Define __KERN_ORG__ inserted to differenciate between original scheduler and our...
authorJens Krieg <jkrieg@mailbox.tu-berlin.de>
Tue, 21 May 2013 14:36:15 +0000 (16:36 +0200)
committerJens Krieg <jkrieg@mailbox.tu-berlin.de>
Tue, 21 May 2013 14:36:15 +0000 (16:36 +0200)
23 files changed:
kernel/Makefile
kernel/sched.new/Makefile [new file with mode: 0644]
kernel/sched.new/clock.c [new file with mode: 0644]
kernel/sched.new/core.c [new file with mode: 0644]
kernel/sched.new/cputime.c [new file with mode: 0644]
kernel/sched.new/sched.h [new file with mode: 0644]
kernel/sched/Makefile
kernel/sched/auto_group.c [new file with mode: 0644]
kernel/sched/auto_group.h [new file with mode: 0644]
kernel/sched/clock.c
kernel/sched/core.c
kernel/sched/cpupri.c [new file with mode: 0644]
kernel/sched/cpupri.h [new file with mode: 0644]
kernel/sched/cputime.c
kernel/sched/debug.c [new file with mode: 0644]
kernel/sched/fair.c [new file with mode: 0644]
kernel/sched/features.h [new file with mode: 0644]
kernel/sched/idle_task.c [new file with mode: 0644]
kernel/sched/rt.c [new file with mode: 0644]
kernel/sched/sched.h
kernel/sched/stats.c [new file with mode: 0644]
kernel/sched/stats.h [new file with mode: 0644]
kernel/sched/stop_task.c [new file with mode: 0644]

index bbde5f1..904c367 100644 (file)
@@ -22,7 +22,11 @@ CFLAGS_REMOVE_cgroup-debug.o = -pg
 CFLAGS_REMOVE_irq_work.o = -pg
 endif
 
+ifdef __KERN_ORG__
 obj-y += sched/
+else
+obj-y += sched.new/
+endif
 obj-y += power/
 
 obj-$(CONFIG_CHECKPOINT_RESTORE) += kcmp.o
diff --git a/kernel/sched.new/Makefile b/kernel/sched.new/Makefile
new file mode 100644 (file)
index 0000000..35630f6
--- /dev/null
@@ -0,0 +1,19 @@
+ifdef CONFIG_FUNCTION_TRACER
+CFLAGS_REMOVE_clock.o = -pg
+endif
+
+ifneq ($(CONFIG_SCHED_OMIT_FRAME_POINTER),y)
+# According to Alan Modra <alan@linuxcare.com.au>, the -fno-omit-frame-pointer is
+# needed for x86 only.  Why this used to be enabled for all architectures is beyond
+# me.  I suspect most platforms don't need this, but until we know that for sure
+# I turn this off for IA-64 only.  Andreas Schwab says it's also needed on m68k
+# to get a correct value for the wait-channel (WCHAN in ps). --davidm
+CFLAGS_core.o := $(PROFILING) -fno-omit-frame-pointer
+endif
+
+obj-y += core.o clock.o cputime.o
+#obj-y += core.o clock.o cputime.o idle_task.o fair.o rt.o stop_task.o
+#obj-$(CONFIG_SMP) += cpupri.o
+#obj-$(CONFIG_SCHED_AUTOGROUP) += auto_group.o
+#obj-$(CONFIG_SCHEDSTATS) += stats.o
+#obj-$(CONFIG_SCHED_DEBUG) += debug.o
diff --git a/kernel/sched.new/clock.c b/kernel/sched.new/clock.c
new file mode 100644 (file)
index 0000000..ea837d4
--- /dev/null
@@ -0,0 +1,27 @@
+
+#include "sched.h"
+
+
+__read_mostly int sched_clock_stable;
+
+/*
+ * We are going deep-idle (irqs are disabled):
+ */
+void sched_clock_idle_sleep_event(void) {
+       return;
+}
+
+/*
+ * We just idled delta nanoseconds (called with irqs disabled):
+ */
+void sched_clock_idle_wakeup_event(u64 delta_ns) {
+       return;
+}
+
+u64 local_clock(void)
+{
+       return 0;
+}
+
+
+
diff --git a/kernel/sched.new/core.c b/kernel/sched.new/core.c
new file mode 100644 (file)
index 0000000..4d584fb
--- /dev/null
@@ -0,0 +1,957 @@
+/*
+ *  kernel/sched/core.c
+ *
+ *  Kernel scheduler and related syscalls
+ *
+ *  Copyright (C) 1991-2002  Linus Torvalds
+ *
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/completion.h>
+#include <linux/kernel_stat.h>
+#include <linux/syscalls.h>
+
+#include <linux/cgroup.h>
+#include "sched.h"
+
+
+
+
+
+//
+// Variables
+//
+
+/*
+ * kernel/sched/rt.c:10
+ * default timeslice is 100 msecs (used only for SCHED_RR tasks).
+ * Timeslices get refilled after they expire. RR_TIMESLICE is defined as
+ * (100 * HZ / 1000) and is assigned to sched_rr_timeslice.
+ */
+int sched_rr_timeslice = RR_TIMESLICE;
+
+/*
+ * kernel/sched/fair.c:80
+ * After fork, child runs first. If set to 0 (default) then
+ * parent will (try to) run first.
+ */
+unsigned int sysctl_sched_child_runs_first = 0;
+
+/*
+ * kernel/sched/core.c:289
+ * Period over which we measure -rt task cpu usage in us.
+ * default: 1s (1000000)
+ */
+unsigned int sysctl_sched_rt_period = 1000000;
+
+/*
+ * /kernel/sched/core.c:2081
+ * Variables and functions for calc_load
+ */
+unsigned long avenrun[3];
+
+/*
+ * kernel/sched/core.c:297
+ * part of the period that we allow rt tasks to run in us.
+ * default: 0.95s (950000)
+ */
+int sysctl_sched_rt_runtime = 950000;
+
+/*
+ * /kernel/sched/core.c:6866
+ *
+ */
+struct task_group root_task_group;
+
+/*
+ * /kernel/sched/core.c:2623
+ * unknown
+ */
+DEFINE_PER_CPU(struct kernel_stat, kstat);
+DEFINE_PER_CPU(struct kernel_cpustat, kernel_cpustat);
+
+
+
+
+
+//
+// Functions
+//
+
+/*
+ * /kernel/sched/cputime.c:436
+ * Account multiple ticks of idle time.
+ * @ticks: number of stolen ticks
+ */
+void account_idle_ticks(unsigned long ticks)
+{
+       return;
+}
+
+/*
+ * /kernel/sched/cputime.c:397
+ * Account a single tick of cpu time.
+ * @p: the process that the cpu time gets accounted to
+ * @user_tick: indicates if the tick is a user or a system tick
+ */
+void account_process_tick(struct task_struct *p, int user_tick)
+{
+       return;
+}
+
+/*
+ * /kernel/sched/core.c:2092
+ * get_avenrun - get the load average array
+ * @loads:    pointer to dest load array
+ * @offset:    offset to add
+ * @shift:    shift count to shift the result left
+ *
+ * These values are estimates at best, so no need for locking.
+ */
+void get_avenrun(unsigned long *loads, unsigned long offset, int shift)
+{
+       return;
+}
+
+/*
+ * /kernel/sched/core.c:2363
+ * calc_load - update the avenrun load estimates 10 ticks after the
+ * CPUs have updated calc_load_tasks.
+ */
+void calc_global_load(unsigned long ticks)
+{
+       return;
+}
+
+/*
+ * /kernel/sched/core.c:2197
+ * We're going into NOHZ mode, if there's any pending delta, fold it
+ * into the pending idle delta.
+ */
+/*void calc_load_enter_idle(void)
+{
+       return;
+}*/
+
+/*
+ * /kernel/sched/core.c:2213
+ * If we're still before the sample window, we're done.
+ *
+ * We woke inside or after the sample window, this means we're already
+ * accounted through the nohz accounting, so skip the entire deal and
+ * sync up for the next window.
+ */
+/*void calc_load_exit_idle(void)
+{
+       return;
+}*/
+
+/*
+ * /kernel/sched/core.c:3668
+ * Check if a task can reduce its nice value
+ * @p: task
+ * @nice: nice value
+ */
+int can_nice(const struct task_struct *p, const int nice)
+{
+       return 0;
+}
+
+/**
+ * kernel/sched/core.c:3768
+ * idle_task - return the idle task for a given cpu.
+ * @cpu: the processor in question.
+ */
+struct task_struct *idle_task(int cpu)
+{
+       return 0;
+}
+
+/**
+ * /kernel/sched/core.c:3742
+ * idle_cpu - is a given cpu idle currently?
+ * @cpu: the processor in question.
+ */
+int idle_cpu(int cpu)
+{
+       return 0;
+}
+
+/**
+ * /kernel/sched/core.c:4674
+ * init_idle - set up an idle thread for a given CPU
+ * @idle: task in question
+ * @cpu: cpu the idle task belongs to
+ *
+ * NOTE: this function does not set the idle thread's NEED_RESCHED
+ * flag, to make booting more robust.
+ */
+void __cpuinit init_idle(struct task_struct *idle, int cpu)
+{
+       return;
+}
+
+/*
+ * /kernel/sched/core.c:4669
+ * Sets sched_class of idle task, see struct sched_class idle_sched_class;
+ */
+void __cpuinit init_idle_bootup_task(struct task_struct *idle)
+{
+       return;
+}
+
+/*
+ * /kernel/sched/core.c:7108
+ * Calls private function
+ * static void normalize_task(struct rq *rq, struct task_struct *p)
+ */
+void normalize_rt_tasks(void)
+{
+       return;
+}
+
+/*
+ * /kernel/sched/core.c:1997
+ * nr_running and nr_context_switches:
+ *
+ * externally visible scheduler statistics:
+ *   current number of runnable threads
+ *   total number of context switches performed since bootup.
+ */
+unsigned long nr_running(void)
+{
+       return 0;
+}
+
+unsigned long long nr_context_switches(void)
+{
+       return 0;
+}
+
+/*
+ * /kernel/sched/core.c:2017
+ * number of threads waiting on IO
+ */
+unsigned long nr_iowait(void)
+{
+       return 0;
+}
+
+/*
+ * rt_mutex_setprio - set the current priority of a task
+ * @p: task
+ * @prio: prio value (kernel-internal form)
+ *
+ * This function changes the 'effective' priority of a task. It does
+ * not touch ->normal_prio like __setscheduler().
+ *
+ * Used by the rt_mutex code to implement priority inheritance logic.
+ */
+void rt_mutex_setprio(struct task_struct *p, int prio)
+{
+       return;
+}
+
+/**
+ * sched_clock_cpu - returns current time in nanosec units
+ * using scheduler clock function.
+ * @param: cpu id
+ */
+u64 sched_clock_cpu(int cpu)
+{
+       return 0;
+}
+
+/*
+ * kernel/sched/clock.c:350
+ * Initialize/Start scheduler clock.
+ */
+void sched_clock_init(void)
+{
+       return;
+}
+
+/*
+ * kernel/sched/core.c:1622
+ * fork()/clone()-time setup:
+ */
+void sched_fork(struct task_struct *p)
+{
+       return;
+}
+
+/**
+ * kernel/sched/core.c:4213
+ * This functions stores the CPU affinity mask for the process or thread with the ID pid in the cpusetsize
+ * bytes long bitmap pointed to by cpuset. If successful, the function always initializes all bits in the
+ * cpu_set_t object and returns zero.
+ *
+ * If pid does not correspond to a process or thread on the system the or the function fails for some other
+ * reason, it returns -1 and errno is set to represent the error condition.
+ */
+long sched_getaffinity(pid_t pid, struct cpumask *mask)
+{
+       return 0;
+}
+
+/**
+ * kernel/sched/core.c:6872
+ * Initialize the scheduler
+ */
+void sched_init(void)
+{
+       printk("sched init\n");
+       return;
+}
+
+/**
+ * kernel/sched/core.c:6850
+ */
+void sched_init_smp(void)
+{
+       return;
+}
+
+/**
+ * kernel/sched/core.c:7571
+ */
+int sched_rr_handler(struct ctl_table *table, int write,
+               void __user *buffer, size_t *lenp,
+               loff_t *ppos)
+{
+       return 0;
+}
+
+/**
+ * kernel/sched/core.c:4111
+ * This function installs the cpusetsize bytes long affinity mask pointed to by cpuset for the process or
+ * thread with the ID pid. If successful the function returns zero and the scheduler will in future take the
+ * affinity information into account.
+ */
+long sched_setaffinity(pid_t pid, const struct cpumask *new_mask)
+{
+       return 0;
+}
+
+/**
+ * kernel/sched/core.c:3975
+ * sched_setscheduler - change the scheduling policy and/or RT priority of a thread.
+ * @p: the task in question.
+ * @policy: new policy.
+ * @param: structure containing the new RT priority.
+ *
+ * NOTE that the task may be already dead.
+ */
+int sched_setscheduler(struct task_struct *p, int policy,
+               const struct sched_param *param)
+{
+       return 0;
+}
+
+/**
+ * kernel/sched/core.c:3993
+ * sched_setscheduler_nocheck - change the scheduling policy and/or RT priority of a thread from kernelspace.
+ * @p: the task in question.
+ * @policy: new policy.
+ * @param: structure containing the new RT priority.
+ *
+ * Just like sched_setscheduler, only don't bother checking if the
+ * current context has permission.  For example, this is needed in
+ * stop_machine(): we create temporary high priority worker threads,
+ * but our caller might not have that capability.
+ */
+int sched_setscheduler_nocheck(struct task_struct *p, int policy,
+const struct sched_param *param)
+{
+       return 0;
+}
+
+/**
+ * kernel/sched/core.c:4601
+ */
+void sched_show_task(struct task_struct *p)
+{
+       return;
+}
+
+/**
+ * kernel/sched/core.c:1905
+ * schedule_tail - first thing a freshly forked thread must call.
+ * @prev: the thread we just switched away from.
+ */
+void schedule_tail(struct task_struct *prev)
+{
+       return;
+}
+
+/*
+ * kernel/sched/core.c:2684
+ * This function gets called by the timer code, with HZ frequency.
+ * We call it with interrupts disabled.
+ */
+void scheduler_tick(void)
+{
+       return;
+}
+
+/*
+ * kernel/sched/core.c:2649
+ * Lock/unlock the current runqueue - to extract task statistics:
+ */
+unsigned long long task_delta_exec(struct task_struct *p)
+{
+       return 0;
+}
+
+/**
+ * kernel/sched/core.c:3727
+ * task_prio - return the priority value of a given task.
+ * @p: the task in question.
+ *
+ * This is the priority value as seen by users in /proc.
+ * RT tasks are offset by -200. Normal tasks are centered
+ * around 0, value goes from -16 to +15.
+ */
+int task_prio(const struct task_struct *p)
+{
+       return 0;
+}
+
+/*
+ * kernel/sched/core.c:2667
+ * Return accounted runtime for the task.
+ * In case the task is currently running, return the runtime plus current's
+ * pending runtime that have not been accounted yet.
+ */
+unsigned long long task_sched_runtime(struct task_struct *task)
+{
+       return 0;
+}
+
+/*
+ * kernel/sched/core.c:2024
+ * this_cpu_load - returns load of the cpu
+ */
+unsigned long this_cpu_load(void)
+{
+       return 0;
+}
+
+/*
+ * kernel/sched/core.c:2556
+ * update_cpu_load_nohz - called from tick_nohz_idle_exit() -- try and fix up the ticks we missed.
+ */
+void update_cpu_load_nohz(void)
+{
+       return;
+}
+
+/*
+ * kernel/sched/core.c:1703
+ * wake_up_new_task - wake up a newly created task for the first time.
+ *
+ * This function will do some initial scheduler statistics housekeeping
+ * that must be done for every newly created context, then puts the task
+ * on the runqueue and wakes it.
+ */
+void wake_up_new_task(struct task_struct *tsk)
+{
+       return;
+}
+
+/*
+ * kernel/sched/core.c:4315
+ */
+int __sched _cond_resched(void)
+{
+       return 0;
+}
+
+/*
+ * kernel/sched/core.c:2966
+ */
+asmlinkage void __sched schedule(void)
+{
+       return;
+}
+
+/**
+ * kernel/sched/core.c:3149
+ * __wake_up - wake up threads blocked on a waitqueue.
+ * @q: the waitqueue
+ * @mode: which threads
+ * @nr_exclusive: how many wake-one or wake-many threads to wake up
+ * @key: is directly passed to the wakeup function
+ *
+ * It may be assumed that this function implies a write memory barrier before
+ * changing the task state if and only if any tasks are woken up.
+ */
+void __wake_up(wait_queue_head_t *q, unsigned int mode, int nr_exclusive, void *key)
+{
+       return;
+}
+
+/**
+ * kernel/sched/core.c:1536
+ * wake_up_process - Wake up a specific process
+ * @p: The process to be woken up.
+ *
+ * Attempt to wake up the nominated process and move it to the set of runnable
+ * processes.  Returns 1 if the process was woken up, 0 if it was already
+ * running.
+ *
+ * It may be assumed that this function implies a write memory barrier before
+ * changing the task state if and only if any tasks are woken up.
+ */
+int wake_up_process(struct task_struct *p)
+{
+       return 0;
+}
+
+/**
+ * kernel/sched/core.c:3322
+ * wait_for_completion: - waits for completion of a task
+ * @x:  holds the state of this particular completion
+ *
+ * This waits to be signaled for completion of a specific task. It is NOT
+ * interruptible and there is no timeout.
+ *
+ * See also similar routines (i.e. wait_for_completion_timeout()) with timeout
+ * and interrupt capability. Also see complete().
+ */
+void __sched wait_for_completion(struct completion *x)
+{
+       return;
+}
+
+/**
+ * kernel/sched/core.c:3231
+ * complete: - signals a single thread waiting on this completion
+ * @x:  holds the state of this particular completion
+ *
+ * This will wake up a single thread waiting on this completion. Threads will be
+ * awakened in the same order in which they were queued.
+ *
+ * See also complete_all(), wait_for_completion() and related routines.
+ *
+ * It may be assumed that this function implies a write memory barrier before
+ * changing the task state if and only if any tasks are woken up.
+ */
+void complete(struct completion *x)
+{
+       return;
+}
+
+/**
+ * kernel/sched/core.c:2995
+ * schedule_preempt_disabled - called with preemption disabled
+ *
+ * Returns with preemption disabled. Note: preempt_count must be 1
+ */
+void __sched schedule_preempt_disabled(void)
+{
+       return;
+}
+
+/*
+ * kernel/sched/core.c:6858
+ */
+int in_sched_functions(unsigned long addr)
+{
+       return 0;
+}
+
+/*
+ * kernel/sched/core.c:4333
+ * __cond_resched_lock() - if a reschedule is pending, drop the given lock,
+ * call schedule, and on return reacquire the lock.
+ *
+ * This works OK both with and without CONFIG_PREEMPT. We do strange low-level
+ * operations here to prevent schedule() from being called twice (once via
+ * spin_unlock(), once by hand).
+ */
+int __cond_resched_lock(spinlock_t *lock)
+{
+       return 0;
+}
+
+/*
+ * kernel/sched/core.c:4333
+ */
+int default_wake_function(wait_queue_t *curr, unsigned mode, int wake_flags, void *key)
+{
+       return 0;
+}
+
+/**
+ * kernel/sched/core.c:3426
+ * wait_for_completion_killable: - waits for completion of a task (killable)
+ * @x:  holds the state of this particular completion
+ *
+ * This waits to be signaled for completion of a specific task. It can be
+ * interrupted by a kill signal.
+ *
+ * The return value is -ERESTARTSYS if interrupted, 0 if completed.
+ */
+int __sched wait_for_completion_killable(struct completion *x)
+{
+       return 0;
+}
+
+/**
+ * kernel/sched/core.c:3192
+ * __wake_up_sync_key - wake up threads blocked on a waitqueue.
+ * @q: the waitqueue
+ * @mode: which threads
+ * @nr_exclusive: how many wake-one or wake-many threads to wake up
+ * @key: opaque value to be passed to wakeup targets
+ *
+ * The sync wakeup differs that the waker knows that it will schedule
+ * away soon, so while the target thread will be woken up, it will not
+ * be migrated to another CPU - ie. the two threads are 'synchronized'
+ * with each other. This can prevent needless bouncing between CPUs.
+ *
+ * On UP it can prevent extra preemption.
+ *
+ * It may be assumed that this function implies a write memory barrier before
+ * changing the task state if and only if any tasks are woken up.
+ */
+void __wake_up_sync_key(wait_queue_head_t *q, unsigned int mode,
+                       int nr_exclusive, void *key)
+{
+       return;
+}
+
+/*
+ * kernel/sched/core.c:1543
+ */
+int wake_up_state(struct task_struct *p, unsigned int state)
+{
+       return 0;
+}
+
+/**
+ * kernel/sched/core.c:4389
+ * yield - yield the current processor to other threads.
+ *
+ * Do not ever use this function, there's a 99% chance you're doing it wrong.
+ *
+ * The scheduler is at all times free to pick the calling task as the most
+ * eligible task to run, if removing the yield() call from your code breaks
+ * it, its already broken.
+ *
+ * Typical broken usage is:
+ *
+ * while (!event)
+ *     yield();
+ *
+ * where one assumes that yield() will let 'the other' process run that will
+ * make event true. If the current task is a SCHED_FIFO task that will never
+ * happen. Never use yield() as a progress guarantee!!
+ *
+ * If you want to use yield() to wait for something, use wait_event().
+ * If you want to use yield() to be 'nice' for others, use cond_resched().
+ * If you still want to use yield(), do not!
+ */
+void __sched yield(void)
+{
+       return;
+}
+
+/**
+ * kernel/sched/core.c:892
+ * task_curr - is this task currently executing on a CPU?
+ * @p: the task in question.
+ */
+inline int task_curr(const struct task_struct *p)
+{
+       return 0;
+}
+
+/**
+ * kernel/sched/core.c:3736
+ * task_nice - return the nice value of a given task.
+ * @p: the task in question.
+ */
+int task_nice(const struct task_struct *p)
+{
+       return 0;
+}
+
+/*
+ * kernel/sched/core.c:3616
+ */
+void set_user_nice(struct task_struct *p, long nice)
+{
+       return;
+}
+
+/*
+ * kernel/sched/core.c:3169
+ */
+void __wake_up_locked_key(wait_queue_head_t *q, unsigned int mode, void *key)
+{
+       return;
+}
+
+/*
+ * kernel/sched/core.c:2018
+ */
+unsigned long nr_iowait_cpu(int cpu)
+{
+       return 0;
+}
+
+/*
+ * kernel/sched/core.c:4474
+ * This task is about to go to sleep on IO. Increment rq->nr_iowait so
+ * that process accounting knows that this is a task in IO wait state.
+ */
+void __sched io_schedule(void)
+{
+       return;
+}
+
+/*
+ * kernel/sched/core.c:4489
+ */
+long __sched io_schedule_timeout(long timeout)
+{
+       return 0;
+}
+
+/*
+ * kernel/sched/core.c:7590
+ */
+int sched_rt_handler(struct ctl_table *table, int write,
+               void __user *buffer, size_t *lenp,
+               loff_t *ppos)
+{
+       return 0;
+}
+
+/*
+ * kernel/sched/core.c:3213
+ * __wake_up_sync - see __wake_up_sync_key()
+ */
+void __wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr_exclusive)
+{
+       return;
+}
+
+/*
+ * kernel/sched/core.c:3163
+ * Same as __wake_up but called with the spinlock in wait_queue_head_t held.
+ */
+void __wake_up_locked(wait_queue_head_t *q, unsigned int mode, int nr)
+{
+       return;
+}
+
+/**
+ * kernel/sched/core.c:3355
+ * wait_for_completion_io: - waits for completion of a task
+ * @x:  holds the state of this particular completion
+ *
+ * This waits to be signaled for completion of a specific task. It is NOT
+ * interruptible and there is no timeout. The caller is accounted as waiting
+ * for IO.
+ */
+void __sched wait_for_completion_io(struct completion *x)
+{
+       return;
+}
+
+/*
+ * kernel/sched/core.c:4634
+ */
+void show_state_filter(unsigned long state_filter)
+{
+       return;
+}
+
+/**
+ * kernel/sched/core.c:3251
+ * complete_all: - signals all threads waiting on this completion
+ * @x:  holds the state of this particular completion
+ *
+ * This will wake up all threads waiting on this particular completion event.
+ *
+ * It may be assumed that this function implies a write memory barrier before
+ * changing the task state if and only if any tasks are woken up.
+ */
+void complete_all(struct completion *x)
+{
+       return;
+}
+
+/**
+ * kernel/sched/core.c:3341
+ * wait_for_completion_timeout: - waits for completion of a task (w/timeout)
+ * @x:  holds the state of this particular completion
+ * @timeout:  timeout value in jiffies
+ *
+ * This waits for either a completion of a specific task to be signaled or for a
+ * specified timeout to expire. The timeout is in jiffies. It is not
+ * interruptible.
+ *
+ * The return value is 0 if timed out, and positive (at least 1, or number of
+ * jiffies left till timeout) if completed.
+ */
+unsigned long __sched
+wait_for_completion_timeout(struct completion *x, unsigned long timeout)
+{
+       return 0;
+}
+
+
+
+
+
+/*
+ * Syscalls
+ *
+ * Help:
+ * SYSCALL_DEFINEx will be replaced by asmlinkage data_type function_name
+ * asmlinkage:         tells the compile that the arguments of the function are
+ *                             not placed in the registers but rather to find on stack
+ */
+
+/*
+ * kernel/sched/core.c:3686
+ * sys_nice - change the priority of the current process.
+ * @increment: priority increment
+ *
+ * sys_setpriority is a more generic, but much slower function that
+ * does similar things.
+ */
+SYSCALL_DEFINE1(nice, int, increment)
+{
+       return 0;
+}
+
+/**
+ * kernel/sched/core.c:4248
+ * sys_sched_getaffinity - get the cpu affinity of a process
+ * @pid: pid of the process
+ * @len: length in bytes of the bitmask pointed to by user_mask_ptr
+ * @user_mask_ptr: user-space pointer to hold the current cpu mask
+ */
+SYSCALL_DEFINE3(sched_getaffinity, pid_t, pid, unsigned int, len,
+               unsigned long __user *, user_mask_ptr)
+{
+       return 0;
+}
+
+/**
+ * kernel/sched/core.c:4197
+ * sys_sched_setaffinity - set the cpu affinity of a process
+ * @pid: pid of the process
+ * @len: length in bytes of the bitmask pointed to by user_mask_ptr
+ * @user_mask_ptr: user-space pointer to the new cpu mask
+ */
+SYSCALL_DEFINE3(sched_setaffinity, pid_t, pid, unsigned int, len,
+               unsigned long __user *, user_mask_ptr)
+{
+       return 0;
+}
+
+/**
+ * kernel/sched/core.c:4562
+ * sys_sched_rr_get_interval - return the default timeslice of a process.
+ * @pid: pid of the process.
+ * @interval: userspace pointer to the timeslice value.
+ *
+ * this syscall writes the default timeslice value of a given process
+ * into the user-space timespec buffer. A value of '0' means infinity.
+ */
+SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid,
+               struct timespec __user *, interval)
+{
+       return 0;
+}
+
+/**
+ * kernel/sched/core.c:4282
+ * sys_sched_yield - yield the current processor to other threads.
+ *
+ * This function yields the current CPU to other tasks. If there are no
+ * other threads running on this CPU then this function will return.
+ */
+SYSCALL_DEFINE0(sched_yield)
+{
+       return 0;
+}
+
+/**
+ * kernel/sched/core.c:4027
+ * sys_sched_setscheduler - set/change the scheduler policy and RT priority
+ * @pid: the pid in question.
+ * @policy: new policy.
+ * @param: structure containing the new RT priority.
+ */
+SYSCALL_DEFINE3(sched_setscheduler, pid_t, pid, int, policy,
+               struct sched_param __user *, param)
+{
+       return 0;
+}
+
+/**
+ * kernel/sched/core.c:4051
+ * sys_sched_getscheduler - get the policy (scheduling class) of a thread
+ * @pid: the pid in question.
+ */
+SYSCALL_DEFINE1(sched_getscheduler, pid_t, pid)
+{
+       return 0;
+}
+
+/**
+ * kernel/sched/core.c:4512
+ * sys_sched_get_priority_max - return maximum RT priority.
+ * @policy: scheduling class.
+ *
+ * this syscall returns the maximum rt_priority that can be used
+ * by a given scheduling class.
+ */
+SYSCALL_DEFINE1(sched_get_priority_max, int, policy)
+{
+       return 0;
+}
+
+/**
+ * kernel/sched/core.c:4537
+ * sys_sched_get_priority_min - return minimum RT priority.
+ * @policy: scheduling class.
+ *
+ * this syscall returns the minimum rt_priority that can be used
+ * by a given scheduling class.
+ */
+SYSCALL_DEFINE1(sched_get_priority_min, int, policy)
+{
+       return 0;
+}
+
+/**
+ * kernel/sched/core.c:4042
+ * sys_sched_setparam - set/change the RT priority of a thread
+ * @pid: the pid in question.
+ * @param: structure containing the new RT priority.
+ */
+SYSCALL_DEFINE2(sched_setparam, pid_t, pid, struct sched_param __user *, param)
+{
+       return 0;
+}
+
+/**
+ * kernel/sched/core.c:4077
+ * sys_sched_getparam - get the RT priority of a thread
+ * @pid: the pid in question.
+ * @param: structure containing the RT priority.
+ */
+SYSCALL_DEFINE2(sched_getparam, pid_t, pid, struct sched_param __user *, param)
+{
+       return 0;
+}
diff --git a/kernel/sched.new/cputime.c b/kernel/sched.new/cputime.c
new file mode 100644 (file)
index 0000000..6b41146
--- /dev/null
@@ -0,0 +1,26 @@
+#include <linux/sched.h>
+#include <linux/kernel_stat.h>
+
+#include "sched.h"
+
+
+struct kernel_cpustat *kcpustat;
+
+void thread_group_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st)
+{
+       return;
+}
+
+/*
+ * Accumulate raw cputime values of dead tasks (sig->[us]time) and live
+ * tasks (sum on group iteration) belonging to @tsk's group.
+ */
+void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times)
+{
+       return;
+}
+
+void task_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st)
+{
+       return;
+}
diff --git a/kernel/sched.new/sched.h b/kernel/sched.new/sched.h
new file mode 100644 (file)
index 0000000..3cfe709
--- /dev/null
@@ -0,0 +1,137 @@
+#include <linux/sched.h>
+#include <linux/sched/sysctl.h>
+#include <linux/sched/rt.h>
+
+
+struct task_group {
+};
+
+struct rq {
+
+};
+
+DECLARE_PER_CPU(struct rq, runqueues);
+
+#define cpu_rq(cpu)            (&per_cpu(runqueues, (cpu)))
+
+void account_idle_ticks(unsigned long ticks);
+
+void account_process_tick(struct task_struct *p, int user_tick);
+
+void get_avenrun(unsigned long *loads, unsigned long offset, int shift);
+
+void calc_global_load(unsigned long ticks);
+
+//void calc_load_enter_idle(void);
+
+//void calc_load_exit_idle(void);
+
+int can_nice(const struct task_struct *p, const int nice);
+
+int idle_cpu(int cpu);
+
+void __cpuinit init_idle(struct task_struct *idle, int cpu);
+
+void __cpuinit init_idle_bootup_task(struct task_struct *idle);
+
+void normalize_rt_tasks(void);
+
+unsigned long nr_running(void);
+
+unsigned long long nr_context_switches(void);
+
+unsigned long nr_iowait(void);
+
+void rt_mutex_setprio(struct task_struct *p, int prio);
+
+u64 sched_clock_cpu(int cpu);
+
+void sched_clock_init(void);;
+
+void sched_fork(struct task_struct *p);
+
+long sched_getaffinity(pid_t pid, struct cpumask *mask);
+
+void sched_init(void);
+
+void sched_init_smp(void);
+
+int sched_rr_handler(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos);
+
+long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
+
+int sched_setscheduler(struct task_struct *p, int policy, const struct sched_param *param);
+
+void sched_show_task(struct task_struct *p);
+
+void schedule_tail(struct task_struct *prev);
+
+void scheduler_tick(void);
+
+long sys_nice(int increment);
+
+long sys_sched_getaffinity(pid_t pid, unsigned int len, unsigned long __user *user_mask_ptr);
+
+long sys_sched_setaffinity(pid_t pid, unsigned int len, unsigned long __user *user_mask_ptr);
+
+unsigned long long task_delta_exec(struct task_struct *);
+
+int task_prio(const struct task_struct *p);
+
+unsigned long long task_sched_runtime(struct task_struct *task);
+
+unsigned long this_cpu_load(void);
+
+void update_cpu_load_nohz(void);
+
+void wake_up_new_task(struct task_struct *tsk);
+
+
+int __sched _cond_resched(void);
+
+asmlinkage void __sched schedule(void);
+
+void __wake_up(wait_queue_head_t *q, unsigned int mode, int nr_exclusive, void *key);
+
+int wake_up_process(struct task_struct *p);
+
+void __sched wait_for_completion(struct completion *x);
+
+void complete(struct completion *x);
+
+void __sched schedule_preempt_disabled(void);
+
+int in_sched_functions(unsigned long addr);
+
+void sched_clock_idle_sleep_event(void);
+
+void sched_clock_idle_wakeup_event(u64 delta_ns);
+
+int __cond_resched_lock(spinlock_t *lock);
+
+u64 local_clock(void);
+
+int default_wake_function(wait_queue_t *curr, unsigned mode, int wake_flags,
+                         void *key);
+
+int __sched wait_for_completion_killable(struct completion *x);
+
+void __wake_up_sync_key(wait_queue_head_t *q, unsigned int mode,
+                       int nr_exclusive, void *key);
+
+int wake_up_state(struct task_struct *p, unsigned int state);
+
+void __sched yield(void);
+
+inline int task_curr(const struct task_struct *p);
+
+int task_nice(const struct task_struct *p);
+
+void set_user_nice(struct task_struct *p, long nice);
+
+void __wake_up_locked_key(wait_queue_head_t *q, unsigned int mode, void *key);
+
+void __wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr_exclusive);
+
+void __wake_up_locked(wait_queue_head_t *q, unsigned int mode, int nr);
+
index 35630f6..f06d249 100644 (file)
@@ -11,9 +11,8 @@ ifneq ($(CONFIG_SCHED_OMIT_FRAME_POINTER),y)
 CFLAGS_core.o := $(PROFILING) -fno-omit-frame-pointer
 endif
 
-obj-y += core.o clock.o cputime.o
-#obj-y += core.o clock.o cputime.o idle_task.o fair.o rt.o stop_task.o
-#obj-$(CONFIG_SMP) += cpupri.o
-#obj-$(CONFIG_SCHED_AUTOGROUP) += auto_group.o
-#obj-$(CONFIG_SCHEDSTATS) += stats.o
-#obj-$(CONFIG_SCHED_DEBUG) += debug.o
+obj-y += core.o clock.o cputime.o idle_task.o fair.o rt.o stop_task.o
+obj-$(CONFIG_SMP) += cpupri.o
+obj-$(CONFIG_SCHED_AUTOGROUP) += auto_group.o
+obj-$(CONFIG_SCHEDSTATS) += stats.o
+obj-$(CONFIG_SCHED_DEBUG) += debug.o
diff --git a/kernel/sched/auto_group.c b/kernel/sched/auto_group.c
new file mode 100644 (file)
index 0000000..64de5f8
--- /dev/null
@@ -0,0 +1,261 @@
+#ifdef CONFIG_SCHED_AUTOGROUP
+
+#include "sched.h"
+
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/kallsyms.h>
+#include <linux/utsname.h>
+#include <linux/security.h>
+#include <linux/export.h>
+
+unsigned int __read_mostly sysctl_sched_autogroup_enabled = 1;
+static struct autogroup autogroup_default;
+static atomic_t autogroup_seq_nr;
+
+void __init autogroup_init(struct task_struct *init_task)
+{
+       autogroup_default.tg = &root_task_group;
+       kref_init(&autogroup_default.kref);
+       init_rwsem(&autogroup_default.lock);
+       init_task->signal->autogroup = &autogroup_default;
+}
+
+void autogroup_free(struct task_group *tg)
+{
+       kfree(tg->autogroup);
+}
+
+static inline void autogroup_destroy(struct kref *kref)
+{
+       struct autogroup *ag = container_of(kref, struct autogroup, kref);
+
+#ifdef CONFIG_RT_GROUP_SCHED
+       /* We've redirected RT tasks to the root task group... */
+       ag->tg->rt_se = NULL;
+       ag->tg->rt_rq = NULL;
+#endif
+       sched_offline_group(ag->tg);
+       sched_destroy_group(ag->tg);
+}
+
+static inline void autogroup_kref_put(struct autogroup *ag)
+{
+       kref_put(&ag->kref, autogroup_destroy);
+}
+
+static inline struct autogroup *autogroup_kref_get(struct autogroup *ag)
+{
+       kref_get(&ag->kref);
+       return ag;
+}
+
+static inline struct autogroup *autogroup_task_get(struct task_struct *p)
+{
+       struct autogroup *ag;
+       unsigned long flags;
+
+       if (!lock_task_sighand(p, &flags))
+               return autogroup_kref_get(&autogroup_default);
+
+       ag = autogroup_kref_get(p->signal->autogroup);
+       unlock_task_sighand(p, &flags);
+
+       return ag;
+}
+
+static inline struct autogroup *autogroup_create(void)
+{
+       struct autogroup *ag = kzalloc(sizeof(*ag), GFP_KERNEL);
+       struct task_group *tg;
+
+       if (!ag)
+               goto out_fail;
+
+       tg = sched_create_group(&root_task_group);
+
+       if (IS_ERR(tg))
+               goto out_free;
+
+       sched_online_group(tg, &root_task_group);
+
+       kref_init(&ag->kref);
+       init_rwsem(&ag->lock);
+       ag->id = atomic_inc_return(&autogroup_seq_nr);
+       ag->tg = tg;
+#ifdef CONFIG_RT_GROUP_SCHED
+       /*
+        * Autogroup RT tasks are redirected to the root task group
+        * so we don't have to move tasks around upon policy change,
+        * or flail around trying to allocate bandwidth on the fly.
+        * A bandwidth exception in __sched_setscheduler() allows
+        * the policy change to proceed.  Thereafter, task_group()
+        * returns &root_task_group, so zero bandwidth is required.
+        */
+       free_rt_sched_group(tg);
+       tg->rt_se = root_task_group.rt_se;
+       tg->rt_rq = root_task_group.rt_rq;
+#endif
+       tg->autogroup = ag;
+
+       return ag;
+
+out_free:
+       kfree(ag);
+out_fail:
+       if (printk_ratelimit()) {
+               printk(KERN_WARNING "autogroup_create: %s failure.\n",
+                       ag ? "sched_create_group()" : "kmalloc()");
+       }
+
+       return autogroup_kref_get(&autogroup_default);
+}
+
+bool task_wants_autogroup(struct task_struct *p, struct task_group *tg)
+{
+       if (tg != &root_task_group)
+               return false;
+
+       if (p->sched_class != &fair_sched_class)
+               return false;
+
+       /*
+        * We can only assume the task group can't go away on us if
+        * autogroup_move_group() can see us on ->thread_group list.
+        */
+       if (p->flags & PF_EXITING)
+               return false;
+
+       return true;
+}
+
+static void
+autogroup_move_group(struct task_struct *p, struct autogroup *ag)
+{
+       struct autogroup *prev;
+       struct task_struct *t;
+       unsigned long flags;
+
+       BUG_ON(!lock_task_sighand(p, &flags));
+
+       prev = p->signal->autogroup;
+       if (prev == ag) {
+               unlock_task_sighand(p, &flags);
+               return;
+       }
+
+       p->signal->autogroup = autogroup_kref_get(ag);
+
+       if (!ACCESS_ONCE(sysctl_sched_autogroup_enabled))
+               goto out;
+
+       t = p;
+       do {
+               sched_move_task(t);
+       } while_each_thread(p, t);
+
+out:
+       unlock_task_sighand(p, &flags);
+       autogroup_kref_put(prev);
+}
+
+/* Allocates GFP_KERNEL, cannot be called under any spinlock */
+void sched_autogroup_create_attach(struct task_struct *p)
+{
+       struct autogroup *ag = autogroup_create();
+
+       autogroup_move_group(p, ag);
+       /* drop extra reference added by autogroup_create() */
+       autogroup_kref_put(ag);
+}
+EXPORT_SYMBOL(sched_autogroup_create_attach);
+
+/* Cannot be called under siglock.  Currently has no users */
+void sched_autogroup_detach(struct task_struct *p)
+{
+       autogroup_move_group(p, &autogroup_default);
+}
+EXPORT_SYMBOL(sched_autogroup_detach);
+
+void sched_autogroup_fork(struct signal_struct *sig)
+{
+       sig->autogroup = autogroup_task_get(current);
+}
+
+void sched_autogroup_exit(struct signal_struct *sig)
+{
+       autogroup_kref_put(sig->autogroup);
+}
+
+static int __init setup_autogroup(char *str)
+{
+       sysctl_sched_autogroup_enabled = 0;
+
+       return 1;
+}
+
+__setup("noautogroup", setup_autogroup);
+
+#ifdef CONFIG_PROC_FS
+
+int proc_sched_autogroup_set_nice(struct task_struct *p, int nice)
+{
+       static unsigned long next = INITIAL_JIFFIES;
+       struct autogroup *ag;
+       int err;
+
+       if (nice < -20 || nice > 19)
+               return -EINVAL;
+
+       err = security_task_setnice(current, nice);
+       if (err)
+               return err;
+
+       if (nice < 0 && !can_nice(current, nice))
+               return -EPERM;
+
+       /* this is a heavy operation taking global locks.. */
+       if (!capable(CAP_SYS_ADMIN) && time_before(jiffies, next))
+               return -EAGAIN;
+
+       next = HZ / 10 + jiffies;
+       ag = autogroup_task_get(p);
+
+       down_write(&ag->lock);
+       err = sched_group_set_shares(ag->tg, prio_to_weight[nice + 20]);
+       if (!err)
+               ag->nice = nice;
+       up_write(&ag->lock);
+
+       autogroup_kref_put(ag);
+
+       return err;
+}
+
+void proc_sched_autogroup_show_task(struct task_struct *p, struct seq_file *m)
+{
+       struct autogroup *ag = autogroup_task_get(p);
+
+       if (!task_group_is_autogroup(ag->tg))
+               goto out;
+
+       down_read(&ag->lock);
+       seq_printf(m, "/autogroup-%ld nice %d\n", ag->id, ag->nice);
+       up_read(&ag->lock);
+
+out:
+       autogroup_kref_put(ag);
+}
+#endif /* CONFIG_PROC_FS */
+
+#ifdef CONFIG_SCHED_DEBUG
+int autogroup_path(struct task_group *tg, char *buf, int buflen)
+{
+       if (!task_group_is_autogroup(tg))
+               return 0;
+
+       return snprintf(buf, buflen, "%s-%ld", "/autogroup", tg->autogroup->id);
+}
+#endif /* CONFIG_SCHED_DEBUG */
+
+#endif /* CONFIG_SCHED_AUTOGROUP */
diff --git a/kernel/sched/auto_group.h b/kernel/sched/auto_group.h
new file mode 100644 (file)
index 0000000..8bd0471
--- /dev/null
@@ -0,0 +1,64 @@
+#ifdef CONFIG_SCHED_AUTOGROUP
+
+#include <linux/kref.h>
+#include <linux/rwsem.h>
+
+struct autogroup {
+       /*
+        * reference doesn't mean how many thread attach to this
+        * autogroup now. It just stands for the number of task
+        * could use this autogroup.
+        */
+       struct kref             kref;
+       struct task_group       *tg;
+       struct rw_semaphore     lock;
+       unsigned long           id;
+       int                     nice;
+};
+
+extern void autogroup_init(struct task_struct *init_task);
+extern void autogroup_free(struct task_group *tg);
+
+static inline bool task_group_is_autogroup(struct task_group *tg)
+{
+       return !!tg->autogroup;
+}
+
+extern bool task_wants_autogroup(struct task_struct *p, struct task_group *tg);
+
+static inline struct task_group *
+autogroup_task_group(struct task_struct *p, struct task_group *tg)
+{
+       int enabled = ACCESS_ONCE(sysctl_sched_autogroup_enabled);
+
+       if (enabled && task_wants_autogroup(p, tg))
+               return p->signal->autogroup->tg;
+
+       return tg;
+}
+
+extern int autogroup_path(struct task_group *tg, char *buf, int buflen);
+
+#else /* !CONFIG_SCHED_AUTOGROUP */
+
+static inline void autogroup_init(struct task_struct *init_task) {  }
+static inline void autogroup_free(struct task_group *tg) { }
+static inline bool task_group_is_autogroup(struct task_group *tg)
+{
+       return 0;
+}
+
+static inline struct task_group *
+autogroup_task_group(struct task_struct *p, struct task_group *tg)
+{
+       return tg;
+}
+
+#ifdef CONFIG_SCHED_DEBUG
+static inline int autogroup_path(struct task_group *tg, char *buf, int buflen)
+{
+       return 0;
+}
+#endif
+
+#endif /* CONFIG_SCHED_AUTOGROUP */
index ea837d4..c3ae144 100644 (file)
+/*
+ * sched_clock for unstable cpu clocks
+ *
+ *  Copyright (C) 2008 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
+ *
+ *  Updates and enhancements:
+ *    Copyright (C) 2008 Red Hat, Inc. Steven Rostedt <srostedt@redhat.com>
+ *
+ * Based on code by:
+ *   Ingo Molnar <mingo@redhat.com>
+ *   Guillaume Chazarain <guichaz@gmail.com>
+ *
+ *
+ * What:
+ *
+ * cpu_clock(i) provides a fast (execution time) high resolution
+ * clock with bounded drift between CPUs. The value of cpu_clock(i)
+ * is monotonic for constant i. The timestamp returned is in nanoseconds.
+ *
+ * ######################### BIG FAT WARNING ##########################
+ * # when comparing cpu_clock(i) to cpu_clock(j) for i != j, time can #
+ * # go backwards !!                                                  #
+ * ####################################################################
+ *
+ * There is no strict promise about the base, although it tends to start
+ * at 0 on boot (but people really shouldn't rely on that).
+ *
+ * cpu_clock(i)       -- can be used from any context, including NMI.
+ * sched_clock_cpu(i) -- must be used with local IRQs disabled (implied by NMI)
+ * local_clock()      -- is cpu_clock() on the current cpu.
+ *
+ * How:
+ *
+ * The implementation either uses sched_clock() when
+ * !CONFIG_HAVE_UNSTABLE_SCHED_CLOCK, which means in that case the
+ * sched_clock() is assumed to provide these properties (mostly it means
+ * the architecture provides a globally synchronized highres time source).
+ *
+ * Otherwise it tries to create a semi stable clock from a mixture of other
+ * clocks, including:
+ *
+ *  - GTOD (clock monotomic)
+ *  - sched_clock()
+ *  - explicit idle events
+ *
+ * We use GTOD as base and use sched_clock() deltas to improve resolution. The
+ * deltas are filtered to provide monotonicity and keeping it within an
+ * expected window.
+ *
+ * Furthermore, explicit sleep and wakeup hooks allow us to account for time
+ * that is otherwise invisible (TSC gets stopped).
+ *
+ *
+ * Notes:
+ *
+ * The !IRQ-safetly of sched_clock() and sched_clock_cpu() comes from things
+ * like cpufreq interrupts that can change the base clock (TSC) multiplier
+ * and cause funny jumps in time -- although the filtering provided by
+ * sched_clock_cpu() should mitigate serious artifacts we cannot rely on it
+ * in general since for !CONFIG_HAVE_UNSTABLE_SCHED_CLOCK we fully rely on
+ * sched_clock().
+ */
+#include <linux/spinlock.h>
+#include <linux/hardirq.h>
+#include <linux/export.h>
+#include <linux/percpu.h>
+#include <linux/ktime.h>
+#include <linux/sched.h>
 
-#include "sched.h"
+/*
+ * Scheduler clock - returns current time in nanosec units.
+ * This is default implementation.
+ * Architectures and sub-architectures can override this.
+ */
+unsigned long long __attribute__((weak)) sched_clock(void)
+{
+       return (unsigned long long)(jiffies - INITIAL_JIFFIES)
+                                       * (NSEC_PER_SEC / HZ);
+}
+EXPORT_SYMBOL_GPL(sched_clock);
 
+__read_mostly int sched_clock_running;
 
+#ifdef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
 __read_mostly int sched_clock_stable;
 
+struct sched_clock_data {
+       u64                     tick_raw;
+       u64                     tick_gtod;
+       u64                     clock;
+};
+
+static DEFINE_PER_CPU_SHARED_ALIGNED(struct sched_clock_data, sched_clock_data);
+
+static inline struct sched_clock_data *this_scd(void)
+{
+       return &__get_cpu_var(sched_clock_data);
+}
+
+static inline struct sched_clock_data *cpu_sdc(int cpu)
+{
+       return &per_cpu(sched_clock_data, cpu);
+}
+
+void sched_clock_init(void)
+{
+       u64 ktime_now = ktime_to_ns(ktime_get());
+       int cpu;
+
+       for_each_possible_cpu(cpu) {
+               struct sched_clock_data *scd = cpu_sdc(cpu);
+
+               scd->tick_raw = 0;
+               scd->tick_gtod = ktime_now;
+               scd->clock = ktime_now;
+       }
+
+       sched_clock_running = 1;
+}
+
+/*
+ * min, max except they take wrapping into account
+ */
+
+static inline u64 wrap_min(u64 x, u64 y)
+{
+       return (s64)(x - y) < 0 ? x : y;
+}
+
+static inline u64 wrap_max(u64 x, u64 y)
+{
+       return (s64)(x - y) > 0 ? x : y;
+}
+
+/*
+ * update the percpu scd from the raw @now value
+ *
+ *  - filter out backward motion
+ *  - use the GTOD tick value to create a window to filter crazy TSC values
+ */
+static u64 sched_clock_local(struct sched_clock_data *scd)
+{
+       u64 now, clock, old_clock, min_clock, max_clock;
+       s64 delta;
+
+again:
+       now = sched_clock();
+       delta = now - scd->tick_raw;
+       if (unlikely(delta < 0))
+               delta = 0;
+
+       old_clock = scd->clock;
+
+       /*
+        * scd->clock = clamp(scd->tick_gtod + delta,
+        *                    max(scd->tick_gtod, scd->clock),
+        *                    scd->tick_gtod + TICK_NSEC);
+        */
+
+       clock = scd->tick_gtod + delta;
+       min_clock = wrap_max(scd->tick_gtod, old_clock);
+       max_clock = wrap_max(old_clock, scd->tick_gtod + TICK_NSEC);
+
+       clock = wrap_max(clock, min_clock);
+       clock = wrap_min(clock, max_clock);
+
+       if (cmpxchg64(&scd->clock, old_clock, clock) != old_clock)
+               goto again;
+
+       return clock;
+}
+
+static u64 sched_clock_remote(struct sched_clock_data *scd)
+{
+       struct sched_clock_data *my_scd = this_scd();
+       u64 this_clock, remote_clock;
+       u64 *ptr, old_val, val;
+
+#if BITS_PER_LONG != 64
+again:
+       /*
+        * Careful here: The local and the remote clock values need to
+        * be read out atomic as we need to compare the values and
+        * then update either the local or the remote side. So the
+        * cmpxchg64 below only protects one readout.
+        *
+        * We must reread via sched_clock_local() in the retry case on
+        * 32bit as an NMI could use sched_clock_local() via the
+        * tracer and hit between the readout of
+        * the low32bit and the high 32bit portion.
+        */
+       this_clock = sched_clock_local(my_scd);
+       /*
+        * We must enforce atomic readout on 32bit, otherwise the
+        * update on the remote cpu can hit inbetween the readout of
+        * the low32bit and the high 32bit portion.
+        */
+       remote_clock = cmpxchg64(&scd->clock, 0, 0);
+#else
+       /*
+        * On 64bit the read of [my]scd->clock is atomic versus the
+        * update, so we can avoid the above 32bit dance.
+        */
+       sched_clock_local(my_scd);
+again:
+       this_clock = my_scd->clock;
+       remote_clock = scd->clock;
+#endif
+
+       /*
+        * Use the opportunity that we have both locks
+        * taken to couple the two clocks: we take the
+        * larger time as the latest time for both
+        * runqueues. (this creates monotonic movement)
+        */
+       if (likely((s64)(remote_clock - this_clock) < 0)) {
+               ptr = &scd->clock;
+               old_val = remote_clock;
+               val = this_clock;
+       } else {
+               /*
+                * Should be rare, but possible:
+                */
+               ptr = &my_scd->clock;
+               old_val = this_clock;
+               val = remote_clock;
+       }
+
+       if (cmpxchg64(ptr, old_val, val) != old_val)
+               goto again;
+
+       return val;
+}
+
+/*
+ * Similar to cpu_clock(), but requires local IRQs to be disabled.
+ *
+ * See cpu_clock().
+ */
+u64 sched_clock_cpu(int cpu)
+{
+       struct sched_clock_data *scd;
+       u64 clock;
+
+       WARN_ON_ONCE(!irqs_disabled());
+
+       if (sched_clock_stable)
+               return sched_clock();
+
+       if (unlikely(!sched_clock_running))
+               return 0ull;
+
+       scd = cpu_sdc(cpu);
+
+       if (cpu != smp_processor_id())
+               clock = sched_clock_remote(scd);
+       else
+               clock = sched_clock_local(scd);
+
+       return clock;
+}
+
+void sched_clock_tick(void)
+{
+       struct sched_clock_data *scd;
+       u64 now, now_gtod;
+
+       if (sched_clock_stable)
+               return;
+
+       if (unlikely(!sched_clock_running))
+               return;
+
+       WARN_ON_ONCE(!irqs_disabled());
+
+       scd = this_scd();
+       now_gtod = ktime_to_ns(ktime_get());
+       now = sched_clock();
+
+       scd->tick_raw = now;
+       scd->tick_gtod = now_gtod;
+       sched_clock_local(scd);
+}
+
 /*
  * We are going deep-idle (irqs are disabled):
  */
-void sched_clock_idle_sleep_event(void) {
-       return;
+void sched_clock_idle_sleep_event(void)
+{
+       sched_clock_cpu(smp_processor_id());
 }
+EXPORT_SYMBOL_GPL(sched_clock_idle_sleep_event);
 
 /*
  * We just idled delta nanoseconds (called with irqs disabled):
  */
-void sched_clock_idle_wakeup_event(u64 delta_ns) {
-       return;
+void sched_clock_idle_wakeup_event(u64 delta_ns)
+{
+       if (timekeeping_suspended)
+               return;
+
+       sched_clock_tick();
+       touch_softlockup_watchdog();
 }
+EXPORT_SYMBOL_GPL(sched_clock_idle_wakeup_event);
 
+/*
+ * As outlined at the top, provides a fast, high resolution, nanosecond
+ * time source that is monotonic per cpu argument and has bounded drift
+ * between cpus.
+ *
+ * ######################### BIG FAT WARNING ##########################
+ * # when comparing cpu_clock(i) to cpu_clock(j) for i != j, time can #
+ * # go backwards !!                                                  #
+ * ####################################################################
+ */
+u64 cpu_clock(int cpu)
+{
+       u64 clock;
+       unsigned long flags;
+
+       local_irq_save(flags);
+       clock = sched_clock_cpu(cpu);
+       local_irq_restore(flags);
+
+       return clock;
+}
+
+/*
+ * Similar to cpu_clock() for the current cpu. Time will only be observed
+ * to be monotonic if care is taken to only compare timestampt taken on the
+ * same CPU.
+ *
+ * See cpu_clock().
+ */
 u64 local_clock(void)
 {
-       return 0;
+       u64 clock;
+       unsigned long flags;
+
+       local_irq_save(flags);
+       clock = sched_clock_cpu(smp_processor_id());
+       local_irq_restore(flags);
+
+       return clock;
 }
 
+#else /* CONFIG_HAVE_UNSTABLE_SCHED_CLOCK */
+
+void sched_clock_init(void)
+{
+       sched_clock_running = 1;
+}
+
+u64 sched_clock_cpu(int cpu)
+{
+       if (unlikely(!sched_clock_running))
+               return 0;
+
+       return sched_clock();
+}
+
+u64 cpu_clock(int cpu)
+{
+       return sched_clock_cpu(cpu);
+}
+
+u64 local_clock(void)
+{
+       return sched_clock_cpu(0);
+}
 
+#endif /* CONFIG_HAVE_UNSTABLE_SCHED_CLOCK */
 
+EXPORT_SYMBOL_GPL(cpu_clock);
+EXPORT_SYMBOL_GPL(local_clock);
index e6eb933..67d0465 100644 (file)
  *
  *  Copyright (C) 1991-2002  Linus Torvalds
  *
- *
+ *  1996-12-23  Modified by Dave Grothe to fix bugs in semaphores and
+ *             make semaphores SMP safe
+ *  1998-11-19 Implemented schedule_timeout() and related stuff
+ *             by Andrea Arcangeli
+ *  2002-01-04 New ultra-scalable O(1) scheduler by Ingo Molnar:
+ *             hybrid priority-list and round-robin design with
+ *             an array-switch method of distributing timeslices
+ *             and per-CPU runqueues.  Cleanups and useful suggestions
+ *             by Davide Libenzi, preemptible kernel bits by Robert Love.
+ *  2003-09-03 Interactivity tuning by Con Kolivas.
+ *  2004-04-02 Scheduler domains code by Nick Piggin
+ *  2007-04-15  Work begun on replacing all interactivity tuning with a
+ *              fair scheduling design by Con Kolivas.
+ *  2007-05-05  Load balancing (smp-nice) and other improvements
+ *              by Peter Williams
+ *  2007-05-06  Interactivity improvements to CFS by Mike Galbraith
+ *  2007-07-01  Group scheduling enhancements by Srivatsa Vaddagiri
+ *  2007-11-29  RT balancing improvements by Steven Rostedt, Gregory Haskins,
+ *              Thomas Gleixner, Mike Kravetz
  */
 
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/nmi.h>
 #include <linux/init.h>
+#include <linux/uaccess.h>
+#include <linux/highmem.h>
+#include <asm/mmu_context.h>
+#include <linux/interrupt.h>
+#include <linux/capability.h>
 #include <linux/completion.h>
 #include <linux/kernel_stat.h>
+#include <linux/debug_locks.h>
+#include <linux/perf_event.h>
+#include <linux/security.h>
+#include <linux/notifier.h>
+#include <linux/profile.h>
+#include <linux/freezer.h>
+#include <linux/vmalloc.h>
+#include <linux/blkdev.h>
+#include <linux/delay.h>
+#include <linux/pid_namespace.h>
+#include <linux/smp.h>
+#include <linux/threads.h>
+#include <linux/timer.h>
+#include <linux/rcupdate.h>
+#include <linux/cpu.h>
+#include <linux/cpuset.h>
+#include <linux/percpu.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/sysctl.h>
 #include <linux/syscalls.h>
+#include <linux/times.h>
+#include <linux/tsacct_kern.h>
+#include <linux/kprobes.h>
+#include <linux/delayacct.h>
+#include <linux/unistd.h>
+#include <linux/pagemap.h>
+#include <linux/hrtimer.h>
+#include <linux/tick.h>
+#include <linux/debugfs.h>
+#include <linux/ctype.h>
+#include <linux/ftrace.h>
+#include <linux/slab.h>
+#include <linux/init_task.h>
+#include <linux/binfmts.h>
+#include <linux/context_tracking.h>
+
+#include <asm/switch_to.h>
+#include <asm/tlb.h>
+#include <asm/irq_regs.h>
+#include <asm/mutex.h>
+#ifdef CONFIG_PARAVIRT
+#include <asm/paravirt.h>
+#endif
 
-#include <linux/cgroup.h>
 #include "sched.h"
+#include "../workqueue_internal.h"
+#include "../smpboot.h"
 
+#define CREATE_TRACE_POINTS
+#include <trace/events/sched.h>
 
+void start_bandwidth_timer(struct hrtimer *period_timer, ktime_t period)
+{
+       unsigned long delta;
+       ktime_t soft, hard, now;
 
-/*
- * kernel/sched/rt.c:10
- * default timeslice is 100 msecs (used only for SCHED_RR tasks).
- * Timeslices get refilled after they expire. RR_TIMESLICE is defined as
- * (100 * HZ / 1000) and is assigned to sched_rr_timeslice.
- */
-int sched_rr_timeslice = RR_TIMESLICE;
+       for (;;) {
+               if (hrtimer_active(period_timer))
+                       break;
 
-/*
- * kernel/sched/fair.c:80
- * After fork, child runs first. If set to 0 (default) then
- * parent will (try to) run first.
- */
-unsigned int sysctl_sched_child_runs_first = 0;
+               now = hrtimer_cb_get_time(period_timer);
+               hrtimer_forward(period_timer, now, period);
 
-/*
- * kernel/sched/core.c:289
- * Period over which we measure -rt task cpu usage in us.
- * default: 1s (1000000)
- */
-unsigned int sysctl_sched_rt_period = 1000000;
+               soft = hrtimer_get_softexpires(period_timer);
+               hard = hrtimer_get_expires(period_timer);
+               delta = ktime_to_ns(ktime_sub(hard, soft));
+               __hrtimer_start_range_ns(period_timer, soft, delta,
+                                        HRTIMER_MODE_ABS_PINNED, 0);
+       }
+}
 
-/*
- * kernel/sched/core.c:297
- * part of the period that we allow rt tasks to run in us.
- * default: 0.95s (950000)
- */
-int sysctl_sched_rt_runtime = 950000;
+DEFINE_MUTEX(sched_domains_mutex);
+DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues);
 
-/*
- * /kernel/sched/core.c:8024
- * No idea.
- */
-struct cgroup_subsys cpu_cgroup_subsys;
+static void update_rq_clock_task(struct rq *rq, s64 delta);
 
-/*
- * /kernel/sched/core.c:8251
- * No idea.
- */
-struct cgroup_subsys cpuacct_subsys;
+void update_rq_clock(struct rq *rq)
+{
+       s64 delta;
+
+       if (rq->skip_clock_update > 0)
+               return;
+
+       delta = sched_clock_cpu(cpu_of(rq)) - rq->clock;
+       rq->clock += delta;
+       update_rq_clock_task(rq, delta);
+}
 
 /*
- * /kernel/sched/core.c:6866
- *
+ * Debugging: various feature bits
  */
-struct task_group root_task_group;
 
+#define SCHED_FEAT(name, enabled)      \
+       (1UL << __SCHED_FEAT_##name) * enabled |
 
-unsigned long avenrun[3];
-DEFINE_PER_CPU(struct kernel_stat, kstat);
-DEFINE_PER_CPU(struct kernel_cpustat, kernel_cpustat);
+const_debug unsigned int sysctl_sched_features =
+#include "features.h"
+       0;
 
+#undef SCHED_FEAT
 
+#ifdef CONFIG_SCHED_DEBUG
+#define SCHED_FEAT(name, enabled)      \
+       #name ,
 
+static const char * const sched_feat_names[] = {
+#include "features.h"
+};
 
+#undef SCHED_FEAT
 
-/*
- * /kernel/sched/cputime.c:436
- * Account multiple ticks of idle time.
- * @ticks: number of stolen ticks
- */
-void account_idle_ticks(unsigned long ticks) {
-       return;
-}
+static int sched_feat_show(struct seq_file *m, void *v)
+{
+       int i;
 
-/*
- * /kernel/sched/cputime.c:397
- * Account a single tick of cpu time.
- * @p: the process that the cpu time gets accounted to
- * @user_tick: indicates if the tick is a user or a system tick
- */
-void account_process_tick(struct task_struct *p, int user_tick) {
-       return;
-}
+       for (i = 0; i < __SCHED_FEAT_NR; i++) {
+               if (!(sysctl_sched_features & (1UL << i)))
+                       seq_puts(m, "NO_");
+               seq_printf(m, "%s ", sched_feat_names[i]);
+       }
+       seq_puts(m, "\n");
 
-/*
- * /kernel/sched/core.c:2092
- * get_avenrun - get the load average array
- * @loads:    pointer to dest load array
- * @offset:    offset to add
- * @shift:    shift count to shift the result left
- *
- * These values are estimates at best, so no need for locking.
- */
-void get_avenrun(unsigned long *loads, unsigned long offset, int shift) {
-       return;
+       return 0;
 }
 
-/*
- * /kernel/sched/core.c:2363
- * calc_load - update the avenrun load estimates 10 ticks after the
- * CPUs have updated calc_load_tasks.
- */
-void calc_global_load(unsigned long ticks) {
-       return;
-}
+#ifdef HAVE_JUMP_LABEL
 
-/*
- * /kernel/sched/core.c:2197
- * We're going into NOHZ mode, if there's any pending delta, fold it
- * into the pending idle delta.
- */
-void calc_load_enter_idle(void) {
-       return;
-}
+#define jump_label_key__true  STATIC_KEY_INIT_TRUE
+#define jump_label_key__false STATIC_KEY_INIT_FALSE
 
-/*
- * /kernel/sched/core.c:2213
- * If we're still before the sample window, we're done.
- *
- * We woke inside or after the sample window, this means we're already
- * accounted through the nohz accounting, so skip the entire deal and
- * sync up for the next window.
- */
-void calc_load_exit_idle(void) {
-       return;
-}
+#define SCHED_FEAT(name, enabled)      \
+       jump_label_key__##enabled ,
 
-/*
- * /kernel/sched/core.c:3668
- * Check if a task can reduce its nice value
- * @p: task
- * @nice: nice value
- */
-int can_nice(const struct task_struct *p, const int nice) {
-       return 0;
-}
+struct static_key sched_feat_keys[__SCHED_FEAT_NR] = {
+#include "features.h"
+};
 
-/**
- * /kernel/sched/core.c:3742
- * idle_cpu - is a given cpu idle currently?
- * @cpu: the processor in question.
- */
-int idle_cpu(int cpu) {
-       return 0;
+#undef SCHED_FEAT
+
+static void sched_feat_disable(int i)
+{
+       if (static_key_enabled(&sched_feat_keys[i]))
+               static_key_slow_dec(&sched_feat_keys[i]);
 }
 
-/**
- * /kernel/sched/core.c:4674
- * init_idle - set up an idle thread for a given CPU
- * @idle: task in question
- * @cpu: cpu the idle task belongs to
- *
- * NOTE: this function does not set the idle thread's NEED_RESCHED
- * flag, to make booting more robust.
- */
-void __cpuinit init_idle(struct task_struct *idle, int cpu) {
-       return;
+static void sched_feat_enable(int i)
+{
+       if (!static_key_enabled(&sched_feat_keys[i]))
+               static_key_slow_inc(&sched_feat_keys[i]);
 }
+#else
+static void sched_feat_disable(int i) { };
+static void sched_feat_enable(int i) { };
+#endif /* HAVE_JUMP_LABEL */
 
-/*
- * /kernel/sched/core.c:4669
- * Sets sched_class of idle task, see struct sched_class idle_sched_class;
- */
-void __cpuinit init_idle_bootup_task(struct task_struct *idle) {
-       return;
+static int sched_feat_set(char *cmp)
+{
+       int i;
+       int neg = 0;
+
+       if (strncmp(cmp, "NO_", 3) == 0) {
+               neg = 1;
+               cmp += 3;
+       }
+
+       for (i = 0; i < __SCHED_FEAT_NR; i++) {
+               if (strcmp(cmp, sched_feat_names[i]) == 0) {
+                       if (neg) {
+                               sysctl_sched_features &= ~(1UL << i);
+                               sched_feat_disable(i);
+                       } else {
+                               sysctl_sched_features |= (1UL << i);
+                               sched_feat_enable(i);
+                       }
+                       break;
+               }
+       }
+
+       return i;
 }
 
-/*
- * /kernel/sched/core.c:7108
- * Calls private function
- * static void normalize_task(struct rq *rq, struct task_struct *p)
- */
-void normalize_rt_tasks(void) {
-       return;
+static ssize_t
+sched_feat_write(struct file *filp, const char __user *ubuf,
+               size_t cnt, loff_t *ppos)
+{
+       char buf[64];
+       char *cmp;
+       int i;
+
+       if (cnt > 63)
+               cnt = 63;
+
+       if (copy_from_user(&buf, ubuf, cnt))
+               return -EFAULT;
+
+       buf[cnt] = 0;
+       cmp = strstrip(buf);
+
+       i = sched_feat_set(cmp);
+       if (i == __SCHED_FEAT_NR)
+               return -EINVAL;
+
+       *ppos += cnt;
+
+       return cnt;
 }
 
-/*
- * /kernel/sched/core.c:1997
- * nr_running and nr_context_switches:
- *
- * externally visible scheduler statistics:
- *   current number of runnable threads
- *   total number of context switches performed since bootup.
- */
-unsigned long nr_running(void) {
-       return 0;
+static int sched_feat_open(struct inode *inode, struct file *filp)
+{
+       return single_open(filp, sched_feat_show, NULL);
 }
 
-unsigned long long nr_context_switches(void) {
+static const struct file_operations sched_feat_fops = {
+       .open           = sched_feat_open,
+       .write          = sched_feat_write,
+       .read           = seq_read,
+       .llseek         = seq_lseek,
+       .release        = single_release,
+};
+
+static __init int sched_init_debug(void)
+{
+       debugfs_create_file("sched_features", 0644, NULL, NULL,
+                       &sched_feat_fops);
+
        return 0;
 }
+late_initcall(sched_init_debug);
+#endif /* CONFIG_SCHED_DEBUG */
 
 /*
- * /kernel/sched/core.c:2017
- * number of threads waiting on IO
+ * Number of tasks to iterate in a single balance run.
+ * Limited because this is done with IRQs disabled.
  */
-unsigned long nr_iowait(void) {
-       return 0;
-}
+const_debug unsigned int sysctl_sched_nr_migrate = 32;
 
 /*
- * rt_mutex_setprio - set the current priority of a task
- * @p: task
- * @prio: prio value (kernel-internal form)
+ * period over which we average the RT time consumption, measured
+ * in ms.
  *
- * This function changes the 'effective' priority of a task. It does
- * not touch ->normal_prio like __setscheduler().
- *
- * Used by the rt_mutex code to implement priority inheritance logic.
+ * default: 1s
  */
-void rt_mutex_setprio(struct task_struct *p, int prio) {
-       return;
-}
+const_debug unsigned int sysctl_sched_time_avg = MSEC_PER_SEC;
 
-/**
- * sched_clock_cpu - returns current time in nanosec units
- * using scheduler clock function.
- * @param: cpu id
+/*
+ * period over which we measure -rt task cpu usage in us.
+ * default: 1s
  */
-u64 sched_clock_cpu(int cpu) {
-       return 0;
-}
+unsigned int sysctl_sched_rt_period = 1000000;
+
+__read_mostly int scheduler_running;
 
 /*
- * kernel/sched/clock.c:350
- * Initialize/Start scheduler clock.
+ * part of the period that we allow rt tasks to run in us.
+ * default: 0.95s
  */
-void sched_clock_init(void) {
-       return;
-}
+int sysctl_sched_rt_runtime = 950000;
+
+
 
 /*
- * kernel/sched/core.c:1622
- * fork()/clone()-time setup:
+ * __task_rq_lock - lock the rq @p resides on.
  */
-void sched_fork(struct task_struct *p) {
-       return;
-}
+static inline struct rq *__task_rq_lock(struct task_struct *p)
+       __acquires(rq->lock)
+{
+       struct rq *rq;
 
-/**
- * kernel/sched/core.c:4213
- * This functions stores the CPU affinity mask for the process or thread with the ID pid in the cpusetsize
- * bytes long bitmap pointed to by cpuset. If successful, the function always initializes all bits in the
- * cpu_set_t object and returns zero.
- *
- * If pid does not correspond to a process or thread on the system the or the function fails for some other
- * reason, it returns -1 and errno is set to represent the error condition.
- */
-long sched_getaffinity(pid_t pid, struct cpumask *mask) {
-       return 0;
-}
+       lockdep_assert_held(&p->pi_lock);
 
-/**
- * kernel/sched/core.c:6872
- * Initialize the scheduler
- */
-void sched_init(void) {
-       return;
+       for (;;) {
+               rq = task_rq(p);
+               raw_spin_lock(&rq->lock);
+               if (likely(rq == task_rq(p)))
+                       return rq;
+               raw_spin_unlock(&rq->lock);
+       }
 }
 
-/**
- * kernel/sched/core.c:6850
+/*
+ * task_rq_lock - lock p->pi_lock and lock the rq @p resides on.
  */
-void sched_init_smp(void) {
-       return;
+static struct rq *task_rq_lock(struct task_struct *p, unsigned long *flags)
+       __acquires(p->pi_lock)
+       __acquires(rq->lock)
+{
+       struct rq *rq;
+
+       for (;;) {
+               raw_spin_lock_irqsave(&p->pi_lock, *flags);
+               rq = task_rq(p);
+               raw_spin_lock(&rq->lock);
+               if (likely(rq == task_rq(p)))
+                       return rq;
+               raw_spin_unlock(&rq->lock);
+               raw_spin_unlock_irqrestore(&p->pi_lock, *flags);
+       }
 }
 
-/**
- * kernel/sched/core.c:7571
- */
-int sched_rr_handler(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) {
-       return 0;
+static void __task_rq_unlock(struct rq *rq)
+       __releases(rq->lock)
+{
+       raw_spin_unlock(&rq->lock);
 }
 
-/**
- * kernel/sched/core.c:4111
- * This function installs the cpusetsize bytes long affinity mask pointed to by cpuset for the process or
- * thread with the ID pid. If successful the function returns zero and the scheduler will in future take the
- * affinity information into account.
- */
-long sched_setaffinity(pid_t pid, const struct cpumask *new_mask) {
-       return 0;
+static inline void
+task_rq_unlock(struct rq *rq, struct task_struct *p, unsigned long *flags)
+       __releases(rq->lock)
+       __releases(p->pi_lock)
+{
+       raw_spin_unlock(&rq->lock);
+       raw_spin_unlock_irqrestore(&p->pi_lock, *flags);
 }
 
-/**
- * kernel/sched/core.c:3975
- * sched_setscheduler - change the scheduling policy and/or RT priority of a thread.
- * @p: the task in question.
- * @policy: new policy.
- * @param: structure containing the new RT priority.
- *
- * NOTE that the task may be already dead.
+/*
+ * this_rq_lock - lock this runqueue and disable interrupts.
  */
-int sched_setscheduler(struct task_struct *p, int policy, const struct sched_param *param) {
-       return 0;
+static struct rq *this_rq_lock(void)
+       __acquires(rq->lock)
+{
+       struct rq *rq;
+
+       local_irq_disable();
+       rq = this_rq();
+       raw_spin_lock(&rq->lock);
+
+       return rq;
 }
 
-/**
- * kernel/sched/core.c:3993
- * sched_setscheduler_nocheck - change the scheduling policy and/or RT priority of a thread from kernelspace.
- * @p: the task in question.
- * @policy: new policy.
- * @param: structure containing the new RT priority.
+#ifdef CONFIG_SCHED_HRTICK
+/*
+ * Use HR-timers to deliver accurate preemption points.
  *
- * Just like sched_setscheduler, only don't bother checking if the
- * current context has permission.  For example, this is needed in
- * stop_machine(): we create temporary high priority worker threads,
- * but our caller might not have that capability.
+ * Its all a bit involved since we cannot program an hrt while holding the
+ * rq->lock. So what we do is store a state in in rq->hrtick_* and ask for a
+ * reschedule event.
+ *
+ * When we get rescheduled we reprogram the hrtick_timer outside of the
+ * rq->lock.
  */
-int sched_setscheduler_nocheck(struct task_struct *p, int policy, const struct sched_param *param) {
-       return 0;
-}
 
-/**
- * kernel/sched/core.c:4601
- */
-void sched_show_task(struct task_struct *p) {
-       return;
+static void hrtick_clear(struct rq *rq)
+{
+       if (hrtimer_active(&rq->hrtick_timer))
+               hrtimer_cancel(&rq->hrtick_timer);
 }
 
-/**
- * kernel/sched/core.c:1905
- * schedule_tail - first thing a freshly forked thread must call.
- * @prev: the thread we just switched away from.
+/*
+ * High-resolution timer tick.
+ * Runs from hardirq context with interrupts disabled.
  */
-void schedule_tail(struct task_struct *prev) {
-       return;
+static enum hrtimer_restart hrtick(struct hrtimer *timer)
+{
+       struct rq *rq = container_of(timer, struct rq, hrtick_timer);
+
+       WARN_ON_ONCE(cpu_of(rq) != smp_processor_id());
+
+       raw_spin_lock(&rq->lock);
+       update_rq_clock(rq);
+       rq->curr->sched_class->task_tick(rq, rq->curr, 1);
+       raw_spin_unlock(&rq->lock);
+
+       return HRTIMER_NORESTART;
 }
 
+#ifdef CONFIG_SMP
 /*
- * kernel/sched/core.c:2684
- * This function gets called by the timer code, with HZ frequency.
- * We call it with interrupts disabled.
+ * called from hardirq (IPI) context
  */
-void scheduler_tick(void) {
-       return;
+static void __hrtick_start(void *arg)
+{
+       struct rq *rq = arg;
+
+       raw_spin_lock(&rq->lock);
+       hrtimer_restart(&rq->hrtick_timer);
+       rq->hrtick_csd_pending = 0;
+       raw_spin_unlock(&rq->lock);
 }
 
-/**
- * kernel/sched/core.c:3686
- * sys_nice - change the priority of the current process.
- * @increment: priority increment
+/*
+ * Called to set the hrtick timer state.
  *
- * sys_setpriority is a more generic, but much slower function that
- * does similar things.
+ * called with rq->lock held and irqs disabled
  */
-long sys_nice(int increment) {
-       return 0;
-}
+void hrtick_start(struct rq *rq, u64 delay)
+{
+       struct hrtimer *timer = &rq->hrtick_timer;
+       ktime_t time = ktime_add_ns(timer->base->get_time(), delay);
 
-/**
- * kernel/sched/core.c:4248
- * sys_sched_getaffinity - get the cpu affinity of a process
- * @pid: pid of the process
- * @len: length in bytes of the bitmask pointed to by user_mask_ptr
- * @user_mask_ptr: user-space pointer to hold the current cpu mask
- */
-long sys_sched_getaffinity(pid_t pid, unsigned int len, unsigned long __user *user_mask_ptr) {
-       return 0;
+       hrtimer_set_expires(timer, time);
+
+       if (rq == this_rq()) {
+               hrtimer_restart(timer);
+       } else if (!rq->hrtick_csd_pending) {
+               __smp_call_function_single(cpu_of(rq), &rq->hrtick_csd, 0);
+               rq->hrtick_csd_pending = 1;
+       }
 }
 
-/**
- * kernel/sched/core.c:4197
- * Set the cpu affinity of a process
- * @pid: pid of the process
- * @len: length in bytes of the bitmask pointed to by user_mask_ptr
- * @user_mask_ptr: user-space pointer to the new cpu mask
- */
-long sys_sched_setaffinity(pid_t pid, unsigned int len, unsigned long __user *user_mask_ptr) {
-       return 0;
+static int
+hotplug_hrtick(struct notifier_block *nfb, unsigned long action, void *hcpu)
+{
+       int cpu = (int)(long)hcpu;
+
+       switch (action) {
+       case CPU_UP_CANCELED:
+       case CPU_UP_CANCELED_FROZEN:
+       case CPU_DOWN_PREPARE:
+       case CPU_DOWN_PREPARE_FROZEN:
+       case CPU_DEAD:
+       case CPU_DEAD_FROZEN:
+               hrtick_clear(cpu_rq(cpu));
+               return NOTIFY_OK;
+       }
+
+       return NOTIFY_DONE;
 }
 
+static __init void init_hrtick(void)
+{
+       hotcpu_notifier(hotplug_hrtick, 0);
+}
+#else
 /*
- * kernel/sched/core.c:2649
- * Lock/unlock the current runqueue - to extract task statistics:
+ * Called to set the hrtick timer state.
+ *
+ * called with rq->lock held and irqs disabled
  */
-unsigned long long task_delta_exec(struct task_struct *p) {
-       return 0;
+void hrtick_start(struct rq *rq, u64 delay)
+{
+       __hrtimer_start_range_ns(&rq->hrtick_timer, ns_to_ktime(delay), 0,
+                       HRTIMER_MODE_REL_PINNED, 0);
 }
 
-/**
- * kernel/sched/core.c:3727
- * task_prio - return the priority value of a given task.
- * @p: the task in question.
- *
- * This is the priority value as seen by users in /proc.
- * RT tasks are offset by -200. Normal tasks are centered
- * around 0, value goes from -16 to +15.
- */
-int task_prio(const struct task_struct *p) {
-       return 0;
+static inline void init_hrtick(void)
+{
 }
+#endif /* CONFIG_SMP */
 
-/*
- * kernel/sched/core.c:2667
- * Return accounted runtime for the task.
- * In case the task is currently running, return the runtime plus current's
- * pending runtime that have not been accounted yet.
- */
-unsigned long long task_sched_runtime(struct task_struct *task) {
-       return 0;
+static void init_rq_hrtick(struct rq *rq)
+{
+#ifdef CONFIG_SMP
+       rq->hrtick_csd_pending = 0;
+
+       rq->hrtick_csd.flags = 0;
+       rq->hrtick_csd.func = __hrtick_start;
+       rq->hrtick_csd.info = rq;
+#endif
+
+       hrtimer_init(&rq->hrtick_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+       rq->hrtick_timer.function = hrtick;
+}
+#else  /* CONFIG_SCHED_HRTICK */
+static inline void hrtick_clear(struct rq *rq)
+{
 }
 
-/*
- * kernel/sched/core.c:2024
- * this_cpu_load - returns load of the cpu
- */
-unsigned long this_cpu_load(void) {
-       return 0;
+static inline void init_rq_hrtick(struct rq *rq)
+{
 }
 
-/*
- * kernel/sched/core.c:2556
- * update_cpu_load_nohz - called from tick_nohz_idle_exit() -- try and fix up the ticks we missed.
- */
-void update_cpu_load_nohz(void) {
-       return;
+static inline void init_hrtick(void)
+{
 }
+#endif /* CONFIG_SCHED_HRTICK */
 
 /*
- * kernel/sched/core.c:1703
- * wake_up_new_task - wake up a newly created task for the first time.
+ * resched_task - mark a task 'to be rescheduled now'.
  *
- * This function will do some initial scheduler statistics housekeeping
- * that must be done for every newly created context, then puts the task
- * on the runqueue and wakes it.
+ * On UP this means the setting of the need_resched flag, on SMP it
+ * might also involve a cross-CPU call to trigger the scheduler on
+ * the target CPU.
  */
-void wake_up_new_task(struct task_struct *tsk) {
-       return;
-}
+#ifdef CONFIG_SMP
 
+#ifndef tsk_is_polling
+#define tsk_is_polling(t) 0
+#endif
 
+void resched_task(struct task_struct *p)
+{
+       int cpu;
 
+       assert_raw_spin_locked(&task_rq(p)->lock);
 
+       if (test_tsk_need_resched(p))
+               return;
 
+       set_tsk_need_resched(p);
 
+       cpu = task_cpu(p);
+       if (cpu == smp_processor_id())
+               return;
 
-int __sched _cond_resched(void)
-{
-       return 0;
+       /* NEED_RESCHED must be visible before we test polling */
+       smp_mb();
+       if (!tsk_is_polling(p))
+               smp_send_reschedule(cpu);
 }
 
-asmlinkage void __sched schedule(void)
+void resched_cpu(int cpu)
 {
-       return;
-}
+       struct rq *rq = cpu_rq(cpu);
+       unsigned long flags;
 
-void __wake_up(wait_queue_head_t *q, unsigned int mode, int nr_exclusive, void *key) {
-       return;
+       if (!raw_spin_trylock_irqsave(&rq->lock, flags))
+               return;
+       resched_task(cpu_curr(cpu));
+       raw_spin_unlock_irqrestore(&rq->lock, flags);
 }
 
-/**
- * wake_up_process - Wake up a specific process
- * @p: The process to be woken up.
+#ifdef CONFIG_NO_HZ
+/*
+ * In the semi idle case, use the nearest busy cpu for migrating timers
+ * from an idle cpu.  This is good for power-savings.
  *
- * Attempt to wake up the nominated process and move it to the set of runnable
- * processes.  Returns 1 if the process was woken up, 0 if it was already
- * running.
- *
- * It may be assumed that this function implies a write memory barrier before
- * changing the task state if and only if any tasks are woken up.
+ * We don't do similar optimization for completely idle system, as
+ * selecting an idle cpu will add more delays to the timers than intended
+ * (as that cpu's timer base may not be uptodate wrt jiffies etc).
  */
-int wake_up_process(struct task_struct *p)
+int get_nohz_timer_target(void)
 {
-       return 0;
-}
+       int cpu = smp_processor_id();
+       int i;
+       struct sched_domain *sd;
 
-/**
- * wait_for_completion: - waits for completion of a task
- * @x:  holds the state of this particular completion
- *
- * This waits to be signaled for completion of a specific task. It is NOT
- * interruptible and there is no timeout.
- *
- * See also similar routines (i.e. wait_for_completion_timeout()) with timeout
- * and interrupt capability. Also see complete().
- */
-void __sched wait_for_completion(struct completion *x) {
-       return;
+       rcu_read_lock();
+       for_each_domain(cpu, sd) {
+               for_each_cpu(i, sched_domain_span(sd)) {
+                       if (!idle_cpu(i)) {
+                               cpu = i;
+                               goto unlock;
+                       }
+               }
+       }
+unlock:
+       rcu_read_unlock();
+       return cpu;
 }
-
-/**
- * complete: - signals a single thread waiting on this completion
- * @x:  holds the state of this particular completion
- *
- * This will wake up a single thread waiting on this completion. Threads will be
- * awakened in the same order in which they were queued.
- *
- * See also complete_all(), wait_for_completion() and related routines.
- *
- * It may be assumed that this function implies a write memory barrier before
- * changing the task state if and only if any tasks are woken up.
+/*
+ * When add_timer_on() enqueues a timer into the timer wheel of an
+ * idle CPU then this timer might expire before the next timer event
+ * which is scheduled to wake up that CPU. In case of a completely
+ * idle system the next event might even be infinite time into the
+ * future. wake_up_idle_cpu() ensures that the CPU is woken up and
+ * leaves the inner idle loop so the newly added timer is taken into
+ * account when the CPU goes back to idle and evaluates the timer
+ * wheel for the next timer event.
  */
-void complete(struct completion *x) {
-       return;
-}
+void wake_up_idle_cpu(int cpu)
+{
+       struct rq *rq = cpu_rq(cpu);
 
-/**
- * schedule_preempt_disabled - called with preemption disabled
- *
- * Returns with preemption disabled. Note: preempt_count must be 1
- */
-void __sched schedule_preempt_disabled(void) {
-       return;
-}
+       if (cpu == smp_processor_id())
+               return;
 
-int in_sched_functions(unsigned long addr) {
-       return 0;
-}
+       /*
+        * This is safe, as this function is called with the timer
+        * wheel base lock of (cpu) held. When the CPU is on the way
+        * to idle and has not yet set rq->curr to idle then it will
+        * be serialized on the timer wheel base lock and take the new
+        * timer into account automatically.
+        */
+       if (rq->curr != rq->idle)
+               return;
 
-/*
- * __cond_resched_lock() - if a reschedule is pending, drop the given lock,
- * call schedule, and on return reacquire the lock.
- *
- * This works OK both with and without CONFIG_PREEMPT. We do strange low-level
- * operations here to prevent schedule() from being called twice (once via
- * spin_unlock(), once by hand).
- */
-int __cond_resched_lock(spinlock_t *lock) {
-       return 0;
+       /*
+        * We can set TIF_RESCHED on the idle task of the other CPU
+        * lockless. The worst case is that the other CPU runs the
+        * idle task through an additional NOOP schedule()
+        */
+       set_tsk_need_resched(rq->idle);
+
+       /* NEED_RESCHED must be visible before we test polling */
+       smp_mb();
+       if (!tsk_is_polling(rq->idle))
+               smp_send_reschedule(cpu);
 }
 
-int default_wake_function(wait_queue_t *curr, unsigned mode, int wake_flags, void *key)
+static inline bool got_nohz_idle_kick(void)
 {
-       return 0;
+       int cpu = smp_processor_id();
+       return idle_cpu(cpu) && test_bit(NOHZ_BALANCE_KICK, nohz_flags(cpu));
 }
 
-/**
- * wait_for_completion_killable: - waits for completion of a task (killable)
- * @x:  holds the state of this particular completion
- *
- * This waits to be signaled for completion of a specific task. It can be
- * interrupted by a kill signal.
- *
- * The return value is -ERESTARTSYS if interrupted, 0 if completed.
- */
-int __sched wait_for_completion_killable(struct completion *x)
+#else /* CONFIG_NO_HZ */
+
+static inline bool got_nohz_idle_kick(void)
 {
-       return 0;
+       return false;
 }
 
-/**
- * __wake_up_sync_key - wake up threads blocked on a waitqueue.
- * @q: the waitqueue
- * @mode: which threads
- * @nr_exclusive: how many wake-one or wake-many threads to wake up
- * @key: opaque value to be passed to wakeup targets
- *
- * The sync wakeup differs that the waker knows that it will schedule
- * away soon, so while the target thread will be woken up, it will not
- * be migrated to another CPU - ie. the two threads are 'synchronized'
- * with each other. This can prevent needless bouncing between CPUs.
- *
- * On UP it can prevent extra preemption.
- *
- * It may be assumed that this function implies a write memory barrier before
- * changing the task state if and only if any tasks are woken up.
- */
-void __wake_up_sync_key(wait_queue_head_t *q, unsigned int mode,
-                       int nr_exclusive, void *key)
+#endif /* CONFIG_NO_HZ */
+
+void sched_avg_update(struct rq *rq)
 {
-       return;
+       s64 period = sched_avg_period();
+
+       while ((s64)(rq->clock - rq->age_stamp) > period) {
+               /*
+                * Inline assembly required to prevent the compiler
+                * optimising this loop into a divmod call.
+                * See __iter_div_u64_rem() for another example of this.
+                */
+               asm("" : "+rm" (rq->age_stamp));
+               rq->age_stamp += period;
+               rq->rt_avg /= 2;
+       }
 }
 
-int wake_up_state(struct task_struct *p, unsigned int state)
+#else /* !CONFIG_SMP */
+void resched_task(struct task_struct *p)
 {
-       return 0;
+       assert_raw_spin_locked(&task_rq(p)->lock);
+       set_tsk_need_resched(p);
 }
+#endif /* CONFIG_SMP */
 
-/**
- * yield - yield the current processor to other threads.
- *
- * Do not ever use this function, there's a 99% chance you're doing it wrong.
- *
- * The scheduler is at all times free to pick the calling task as the most
- * eligible task to run, if removing the yield() call from your code breaks
- * it, its already broken.
- *
- * Typical broken usage is:
- *
- * while (!event)
- *     yield();
- *
- * where one assumes that yield() will let 'the other' process run that will
- * make event true. If the current task is a SCHED_FIFO task that will never
- * happen. Never use yield() as a progress guarantee!!
+#if defined(CONFIG_RT_GROUP_SCHED) || (defined(CONFIG_FAIR_GROUP_SCHED) && \
+                       (defined(CONFIG_SMP) || defined(CONFIG_CFS_BANDWIDTH)))
+/*
+ * Iterate task_group tree rooted at *from, calling @down when first entering a
+ * node and @up when leaving it for the final time.
  *
- * If you want to use yield() to wait for something, use wait_event().
- * If you want to use yield() to be 'nice' for others, use cond_resched().
- * If you still want to use yield(), do not!
+ * Caller must hold rcu_lock or sufficient equivalent.
  */
-void __sched yield(void)
+int walk_tg_tree_from(struct task_group *from,
+                            tg_visitor down, tg_visitor up, void *data)
 {
-       return;
-}
+       struct task_group *parent, *child;
+       int ret;
 
+       parent = from;
 
-/**
- * task_curr - is this task currently executing on a CPU?
- * @p: the task in question.
- */
-inline int task_curr(const struct task_struct *p)
+down:
+       ret = (*down)(parent, data);
+       if (ret)
+               goto out;
+       list_for_each_entry_rcu(child, &parent->children, siblings) {
+               parent = child;
+               goto down;
+
+up:
+               continue;
+       }
+       ret = (*up)(parent, data);
+       if (ret || parent == from)
+               goto out;
+
+       child = parent;
+       parent = parent->parent;
+       if (parent)
+               goto up;
+out:
+       return ret;
+}
+
+int tg_nop(struct task_group *tg, void *data)
 {
        return 0;
 }
+#endif
 
-
-/**
- * task_nice - return the nice value of a given task.
- * @p: the task in question.
- */
-int task_nice(const struct task_struct *p)
+static void set_load_weight(struct task_struct *p)
 {
-       return 0;
+       int prio = p->static_prio - MAX_RT_PRIO;
+       struct load_weight *load = &p->se.load;
+
+       /*
+        * SCHED_IDLE tasks get minimal weight:
+        */
+       if (p->policy == SCHED_IDLE) {
+               load->weight = scale_load(WEIGHT_IDLEPRIO);
+               load->inv_weight = WMULT_IDLEPRIO;
+               return;
+       }
+
+       load->weight = scale_load(prio_to_weight[prio]);
+       load->inv_weight = prio_to_wmult[prio];
 }
 
-void set_user_nice(struct task_struct *p, long nice)
+static void enqueue_task(struct rq *rq, struct task_struct *p, int flags)
 {
-       return;
+       update_rq_clock(rq);
+       sched_info_queued(p);
+       p->sched_class->enqueue_task(rq, p, flags);
 }
 
-void __wake_up_locked_key(wait_queue_head_t *q, unsigned int mode, void *key)
+static void dequeue_task(struct rq *rq, struct task_struct *p, int flags)
 {
-       return;
+       update_rq_clock(rq);
+       sched_info_dequeued(p);
+       p->sched_class->dequeue_task(rq, p, flags);
 }
 
-unsigned long nr_iowait_cpu(int cpu)
+void activate_task(struct rq *rq, struct task_struct *p, int flags)
 {
-       return 0;
+       if (task_contributes_to_load(p))
+               rq->nr_uninterruptible--;
+
+       enqueue_task(rq, p, flags);
 }
 
-/**
- * idle_task - return the idle task for a given cpu.
- * @cpu: the processor in question.
- */
-struct task_struct *idle_task(int cpu)
+void deactivate_task(struct rq *rq, struct task_struct *p, int flags)
 {
-       return 0;
+       if (task_contributes_to_load(p))
+               rq->nr_uninterruptible++;
+
+       dequeue_task(rq, p, flags);
 }
 
+static void update_rq_clock_task(struct rq *rq, s64 delta)
+{
 /*
- * This task is about to go to sleep on IO. Increment rq->nr_iowait so
- * that process accounting knows that this is a task in IO wait state.
+ * In theory, the compile should just see 0 here, and optimize out the call
+ * to sched_rt_avg_update. But I don't trust it...
  */
-void __sched io_schedule(void)
-{
-       return;
+#if defined(CONFIG_IRQ_TIME_ACCOUNTING) || defined(CONFIG_PARAVIRT_TIME_ACCOUNTING)
+       s64 steal = 0, irq_delta = 0;
+#endif
+#ifdef CONFIG_IRQ_TIME_ACCOUNTING
+       irq_delta = irq_time_read(cpu_of(rq)) - rq->prev_irq_time;
+
+       /*
+        * Since irq_time is only updated on {soft,}irq_exit, we might run into
+        * this case when a previous update_rq_clock() happened inside a
+        * {soft,}irq region.
+        *
+        * When this happens, we stop ->clock_task and only update the
+        * prev_irq_time stamp to account for the part that fit, so that a next
+        * update will consume the rest. This ensures ->clock_task is
+        * monotonic.
+        *
+        * It does however cause some slight miss-attribution of {soft,}irq
+        * time, a more accurate solution would be to update the irq_time using
+        * the current rq->clock timestamp, except that would require using
+        * atomic ops.
+        */
+       if (irq_delta > delta)
+               irq_delta = delta;
+
+       rq->prev_irq_time += irq_delta;
+       delta -= irq_delta;
+#endif
+#ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING
+       if (static_key_false((&paravirt_steal_rq_enabled))) {
+               u64 st;
+
+               steal = paravirt_steal_clock(cpu_of(rq));
+               steal -= rq->prev_steal_time_rq;
+
+               if (unlikely(steal > delta))
+                       steal = delta;
+
+               st = steal_ticks(steal);
+               steal = st * TICK_NSEC;
+
+               rq->prev_steal_time_rq += steal;
+
+               delta -= steal;
+       }
+#endif
+
+       rq->clock_task += delta;
+
+#if defined(CONFIG_IRQ_TIME_ACCOUNTING) || defined(CONFIG_PARAVIRT_TIME_ACCOUNTING)
+       if ((irq_delta + steal) && sched_feat(NONTASK_POWER))
+               sched_rt_avg_update(rq, irq_delta + steal);
+#endif
 }
 
-long __sched io_schedule_timeout(long timeout)
+void sched_set_stop_task(int cpu, struct task_struct *stop)
 {
-       return 0;
+       struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 };
+       struct task_struct *old_stop = cpu_rq(cpu)->stop;
+
+       if (stop) {
+               /*
+                * Make it appear like a SCHED_FIFO task, its something
+                * userspace knows about and won't get confused about.
+                *
+                * Also, it will make PI more or less work without too
+                * much confusion -- but then, stop work should not
+                * rely on PI working anyway.
+                */
+               sched_setscheduler_nocheck(stop, SCHED_FIFO, &param);
+
+               stop->sched_class = &stop_sched_class;
+       }
+
+       cpu_rq(cpu)->stop = stop;
+
+       if (old_stop) {
+               /*
+                * Reset it back to a normal scheduling class so that
+                * it can die in pieces.
+                */
+               old_stop->sched_class = &rt_sched_class;
+       }
 }
 
-int sched_rt_handler(struct ctl_table *table, int write,
-               void __user *buffer, size_t *lenp,
-               loff_t *ppos)
+/*
+ * __normal_prio - return the priority that is based on the static prio
+ */
+static inline int __normal_prio(struct task_struct *p)
 {
-       return 0;
+       return p->static_prio;
 }
 
 /*
- * __wake_up_sync - see __wake_up_sync_key()
+ * Calculate the expected normal priority: i.e. priority
+ * without taking RT-inheritance into account. Might be
+ * boosted by interactivity modifiers. Changes upon fork,
+ * setprio syscalls, and whenever the interactivity
+ * estimator recalculates.
  */
-void __wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr_exclusive)
+static inline int normal_prio(struct task_struct *p)
 {
-       return;
-}
+       int prio;
 
+       if (task_has_rt_policy(p))
+               prio = MAX_RT_PRIO-1 - p->rt_priority;
+       else
+               prio = __normal_prio(p);
+       return prio;
+}
 
 /*
- * Same as __wake_up but called with the spinlock in wait_queue_head_t held.
+ * Calculate the current priority, i.e. the priority
+ * taken into account by the scheduler. This value might
+ * be boosted by RT tasks, or might be boosted by
+ * interactivity modifiers. Will be RT if the task got
+ * RT-boosted. If not then it returns p->normal_prio.
  */
-void __wake_up_locked(wait_queue_head_t *q, unsigned int mode, int nr)
+static int effective_prio(struct task_struct *p)
 {
-       return;
+       p->normal_prio = normal_prio(p);
+       /*
+        * If we are RT tasks or we were boosted to RT priority,
+        * keep the priority unchanged. Otherwise, update priority
+        * to the normal priority:
+        */
+       if (!rt_prio(p->prio))
+               return p->normal_prio;
+       return p->prio;
 }
 
 /**
- * wait_for_completion_io: - waits for completion of a task
- * @x:  holds the state of this particular completion
- *
- * This waits to be signaled for completion of a specific task. It is NOT
- * interruptible and there is no timeout. The caller is accounted as waiting
- * for IO.
+ * task_curr - is this task currently executing on a CPU?
+ * @p: the task in question.
  */
-void __sched wait_for_completion_io(struct completion *x)
+inline int task_curr(const struct task_struct *p)
 {
-       return;
+       return cpu_curr(task_cpu(p)) == p;
 }
 
-void show_state_filter(unsigned long state_filter)
+static inline void check_class_changed(struct rq *rq, struct task_struct *p,
+                                      const struct sched_class *prev_class,
+                                      int oldprio)
 {
-       return;
+       if (prev_class != p->sched_class) {
+               if (prev_class->switched_from)
+                       prev_class->switched_from(rq, p);
+               p->sched_class->switched_to(rq, p);
+       } else if (oldprio != p->prio)
+               p->sched_class->prio_changed(rq, p, oldprio);
 }
 
-/**
- * complete_all: - signals all threads waiting on this completion
- * @x:  holds the state of this particular completion
+void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags)
+{
+       const struct sched_class *class;
+
+       if (p->sched_class == rq->curr->sched_class) {
+               rq->curr->sched_class->check_preempt_curr(rq, p, flags);
+       } else {
+               for_each_class(class) {
+                       if (class == rq->curr->sched_class)
+                               break;
+                       if (class == p->sched_class) {
+                               resched_task(rq->curr);
+                               break;
+                       }
+               }
+       }
+
+       /*
+        * A queue event has occurred, and we're going to schedule.  In
+        * this case, we can save a useless back to back clock update.
+        */
+       if (rq->curr->on_rq && test_tsk_need_resched(rq->curr))
+               rq->skip_clock_update = 1;
+}
+
+static ATOMIC_NOTIFIER_HEAD(task_migration_notifier);
+
+void register_task_migration_notifier(struct notifier_block *n)
+{
+       atomic_notifier_chain_register(&task_migration_notifier, n);
+}
+
+#ifdef CONFIG_SMP
+void set_task_cpu(struct task_struct *p, unsigned int new_cpu)
+{
+#ifdef CONFIG_SCHED_DEBUG
+       /*
+        * We should never call set_task_cpu() on a blocked task,
+        * ttwu() will sort out the placement.
+        */
+       WARN_ON_ONCE(p->state != TASK_RUNNING && p->state != TASK_WAKING &&
+                       !(task_thread_info(p)->preempt_count & PREEMPT_ACTIVE));
+
+#ifdef CONFIG_LOCKDEP
+       /*
+        * The caller should hold either p->pi_lock or rq->lock, when changing
+        * a task's CPU. ->pi_lock for waking tasks, rq->lock for runnable tasks.
+        *
+        * sched_move_task() holds both and thus holding either pins the cgroup,
+        * see task_group().
+        *
+        * Furthermore, all task_rq users should acquire both locks, see
+        * task_rq_lock().
+        */
+       WARN_ON_ONCE(debug_locks && !(lockdep_is_held(&p->pi_lock) ||
+                                     lockdep_is_held(&task_rq(p)->lock)));
+#endif
+#endif
+
+       trace_sched_migrate_task(p, new_cpu);
+
+       if (task_cpu(p) != new_cpu) {
+               struct task_migration_notifier tmn;
+
+               if (p->sched_class->migrate_task_rq)
+                       p->sched_class->migrate_task_rq(p, new_cpu);
+               p->se.nr_migrations++;
+               perf_sw_event(PERF_COUNT_SW_CPU_MIGRATIONS, 1, NULL, 0);
+
+               tmn.task = p;
+               tmn.from_cpu = task_cpu(p);
+               tmn.to_cpu = new_cpu;
+
+               atomic_notifier_call_chain(&task_migration_notifier, 0, &tmn);
+       }
+
+       __set_task_cpu(p, new_cpu);
+}
+
+struct migration_arg {
+       struct task_struct *task;
+       int dest_cpu;
+};
+
+static int migration_cpu_stop(void *data);
+
+/*
+ * wait_task_inactive - wait for a thread to unschedule.
  *
- * This will wake up all threads waiting on this particular completion event.
+ * If @match_state is nonzero, it's the @p->state value just checked and
+ * not expected to change.  If it changes, i.e. @p might have woken up,
+ * then return zero.  When we succeed in waiting for @p to be off its CPU,
+ * we return a positive number (its total switch count).  If a second call
+ * a short while later returns the same number, the caller can be sure that
+ * @p has remained unscheduled the whole time.
  *
- * It may be assumed that this function implies a write memory barrier before
- * changing the task state if and only if any tasks are woken up.
+ * The caller must ensure that the task *will* unschedule sometime soon,
+ * else this function might spin for a *long* time. This function can't
+ * be called with interrupts off, or it may introduce deadlock with
+ * smp_call_function() if an IPI is sent by the same process we are
+ * waiting to become inactive.
  */
-void complete_all(struct completion *x)
+unsigned long wait_task_inactive(struct task_struct *p, long match_state)
 {
-       return;
+       unsigned long flags;
+       int running, on_rq;
+       unsigned long ncsw;
+       struct rq *rq;
+
+       for (;;) {
+               /*
+                * We do the initial early heuristics without holding
+                * any task-queue locks at all. We'll only try to get
+                * the runqueue lock when things look like they will
+                * work out!
+                */
+               rq = task_rq(p);
+
+               /*
+                * If the task is actively running on another CPU
+                * still, just relax and busy-wait without holding
+                * any locks.
+                *
+                * NOTE! Since we don't hold any locks, it's not
+                * even sure that "rq" stays as the right runqueue!
+                * But we don't care, since "task_running()" will
+                * return false if the runqueue has changed and p
+                * is actually now running somewhere else!
+                */
+               while (task_running(rq, p)) {
+                       if (match_state && unlikely(p->state != match_state))
+                               return 0;
+                       cpu_relax();
+               }
+
+               /*
+                * Ok, time to look more closely! We need the rq
+                * lock now, to be *sure*. If we're wrong, we'll
+                * just go back and repeat.
+                */
+               rq = task_rq_lock(p, &flags);
+               trace_sched_wait_task(p);
+               running = task_running(rq, p);
+               on_rq = p->on_rq;
+               ncsw = 0;
+               if (!match_state || p->state == match_state)
+                       ncsw = p->nvcsw | LONG_MIN; /* sets MSB */
+               task_rq_unlock(rq, p, &flags);
+
+               /*
+                * If it changed from the expected state, bail out now.
+                */
+               if (unlikely(!ncsw))
+                       break;
+
+               /*
+                * Was it really running after all now that we
+                * checked with the proper locks actually held?
+                *
+                * Oops. Go back and try again..
+                */
+               if (unlikely(running)) {
+                       cpu_relax();
+                       continue;
+               }
+
+               /*
+                * It's not enough that it's not actively running,
+                * it must be off the runqueue _entirely_, and not
+                * preempted!
+                *
+                * So if it was still runnable (but just not actively
+                * running right now), it's preempted, and we should
+                * yield - it could be a while.
+                */
+               if (unlikely(on_rq)) {
+                       ktime_t to = ktime_set(0, NSEC_PER_SEC/HZ);
+
+                       set_current_state(TASK_UNINTERRUPTIBLE);
+                       schedule_hrtimeout(&to, HRTIMER_MODE_REL);
+                       continue;
+               }
+
+               /*
+                * Ahh, all good. It wasn't running, and it wasn't
+                * runnable, which means that it will never become
+                * running in the future either. We're all done!
+                */
+               break;
+       }
+
+       return ncsw;
 }
 
-/**
- * wait_for_completion_timeout: - waits for completion of a task (w/timeout)
- * @x:  holds the state of this particular completion
- * @timeout:  timeout value in jiffies
+/***
+ * kick_process - kick a running thread to enter/exit the kernel
+ * @p: the to-be-kicked thread
  *
- * This waits for either a completion of a specific task to be signaled or for a
- * specified timeout to expire. The timeout is in jiffies. It is not
- * interruptible.
+ * Cause a process which is running on another CPU to enter
+ * kernel-mode, without any delay. (to get signals handled.)
  *
- * The return value is 0 if timed out, and positive (at least 1, or number of
- * jiffies left till timeout) if completed.
+ * NOTE: this function doesn't have to take the runqueue lock,
+ * because all it wants to ensure is that the remote task enters
+ * the kernel. If the IPI races and the task has been migrated
+ * to another CPU then no harm is done and the purpose has been
+ * achieved as well.
  */
-unsigned long __sched
-wait_for_completion_timeout(struct completion *x, unsigned long timeout)
+void kick_process(struct task_struct *p)
 {
-       return 0;
+       int cpu;
+
+       preempt_disable();
+       cpu = task_cpu(p);
+       if ((cpu != smp_processor_id()) && task_curr(p))
+               smp_send_reschedule(cpu);
+       preempt_enable();
 }
+EXPORT_SYMBOL_GPL(kick_process);
+#endif /* CONFIG_SMP */
 
-/**
- * sys_sched_rr_get_interval - return the default timeslice of a process.
- * @pid: pid of the process.
- * @interval: userspace pointer to the timeslice value.
- *
- * this syscall writes the default timeslice value of a given process
- * into the user-space timespec buffer. A value of '0' means infinity.
+#ifdef CONFIG_SMP
+/*
+ * ->cpus_allowed is protected by both rq->lock and p->pi_lock
  */
-SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid,
-               struct timespec __user *, interval)
+static int select_fallback_rq(int cpu, struct task_struct *p)
 {
-       return 0;
+       int nid = cpu_to_node(cpu);
+       const struct cpumask *nodemask = NULL;
+       enum { cpuset, possible, fail } state = cpuset;
+       int dest_cpu;
+
+       /*
+        * If the node that the cpu is on has been offlined, cpu_to_node()
+        * will return -1. There is no cpu on the node, and we should
+        * select the cpu on the other node.
+        */
+       if (nid != -1) {
+               nodemask = cpumask_of_node(nid);
+
+               /* Look for allowed, online CPU in same node. */
+               for_each_cpu(dest_cpu, nodemask) {
+                       if (!cpu_online(dest_cpu))
+                               continue;
+                       if (!cpu_active(dest_cpu))
+                               continue;
+                       if (cpumask_test_cpu(dest_cpu, tsk_cpus_allowed(p)))
+                               return dest_cpu;
+               }
+       }
+
+       for (;;) {
+               /* Any allowed, online CPU? */
+               for_each_cpu(dest_cpu, tsk_cpus_allowed(p)) {
+                       if (!cpu_online(dest_cpu))
+                               continue;
+                       if (!cpu_active(dest_cpu))
+                               continue;
+                       goto out;
+               }
+
+               switch (state) {
+               case cpuset:
+                       /* No more Mr. Nice Guy. */
+                       cpuset_cpus_allowed_fallback(p);
+                       state = possible;
+                       break;
+
+               case possible:
+                       do_set_cpus_allowed(p, cpu_possible_mask);
+                       state = fail;
+                       break;
+
+               case fail:
+                       BUG();
+                       break;
+               }
+       }
+
+out:
+       if (state != cpuset) {
+               /*
+                * Don't tell them about moving exiting tasks or
+                * kernel threads (both mm NULL), since they never
+                * leave kernel.
+                */
+               if (p->mm && printk_ratelimit()) {
+                       printk_sched("process %d (%s) no longer affine to cpu%d\n",
+                                       task_pid_nr(p), p->comm, cpu);
+               }
+       }
+
+       return dest_cpu;
+}
+
+/*
+ * The caller (fork, wakeup) owns p->pi_lock, ->cpus_allowed is stable.
+ */
+static inline
+int select_task_rq(struct task_struct *p, int sd_flags, int wake_flags)
+{
+       int cpu = p->sched_class->select_task_rq(p, sd_flags, wake_flags);
+
+       /*
+        * In order not to call set_task_cpu() on a blocking task we need
+        * to rely on ttwu() to place the task on a valid ->cpus_allowed
+        * cpu.
+        *
+        * Since this is common to all placement strategies, this lives here.
+        *
+        * [ this allows ->select_task() to simply return task_cpu(p) and
+        *   not worry about this generic constraint ]
+        */
+       if (unlikely(!cpumask_test_cpu(cpu, tsk_cpus_allowed(p)) ||
+                    !cpu_online(cpu)))
+               cpu = select_fallback_rq(task_cpu(p), p);
+
+       return cpu;
+}
+
+static void update_avg(u64 *avg, u64 sample)
+{
+       s64 diff = sample - *avg;
+       *avg += diff >> 3;
+}
+#endif
+
+static void
+ttwu_stat(struct task_struct *p, int cpu, int wake_flags)
+{
+#ifdef CONFIG_SCHEDSTATS
+       struct rq *rq = this_rq();
+
+#ifdef CONFIG_SMP
+       int this_cpu = smp_processor_id();
+
+       if (cpu == this_cpu) {
+               schedstat_inc(rq, ttwu_local);
+               schedstat_inc(p, se.statistics.nr_wakeups_local);
+       } else {
+               struct sched_domain *sd;
+
+               schedstat_inc(p, se.statistics.nr_wakeups_remote);
+               rcu_read_lock();
+               for_each_domain(this_cpu, sd) {
+                       if (cpumask_test_cpu(cpu, sched_domain_span(sd))) {
+                               schedstat_inc(sd, ttwu_wake_remote);
+                               break;
+                       }
+               }
+               rcu_read_unlock();
+       }
+
+       if (wake_flags & WF_MIGRATED)
+               schedstat_inc(p, se.statistics.nr_wakeups_migrate);
+
+#endif /* CONFIG_SMP */
+
+       schedstat_inc(rq, ttwu_count);
+       schedstat_inc(p, se.statistics.nr_wakeups);
+
+       if (wake_flags & WF_SYNC)
+               schedstat_inc(p, se.statistics.nr_wakeups_sync);
+
+#endif /* CONFIG_SCHEDSTATS */
+}
+
+static void ttwu_activate(struct rq *rq, struct task_struct *p, int en_flags)
+{
+       activate_task(rq, p, en_flags);
+       p->on_rq = 1;
+
+       /* if a worker is waking up, notify workqueue */
+       if (p->flags & PF_WQ_WORKER)
+               wq_worker_waking_up(p, cpu_of(rq));
+}
+
+/*
+ * Mark the task runnable and perform wakeup-preemption.
+ */
+static void
+ttwu_do_wakeup(struct rq *rq, struct task_struct *p, int wake_flags)
+{
+       trace_sched_wakeup(p, true);
+       check_preempt_curr(rq, p, wake_flags);
+
+       p->state = TASK_RUNNING;
+#ifdef CONFIG_SMP
+       if (p->sched_class->task_woken)
+               p->sched_class->task_woken(rq, p);
+
+       if (rq->idle_stamp) {
+               u64 delta = rq->clock - rq->idle_stamp;
+               u64 max = 2*sysctl_sched_migration_cost;
+
+               if (delta > max)
+                       rq->avg_idle = max;
+               else
+                       update_avg(&rq->avg_idle, delta);
+               rq->idle_stamp = 0;
+       }
+#endif
+}
+
+static void
+ttwu_do_activate(struct rq *rq, struct task_struct *p, int wake_flags)
+{
+#ifdef CONFIG_SMP
+       if (p->sched_contributes_to_load)
+               rq->nr_uninterruptible--;
+#endif
+
+       ttwu_activate(rq, p, ENQUEUE_WAKEUP | ENQUEUE_WAKING);
+       ttwu_do_wakeup(rq, p, wake_flags);
+}
+
+/*
+ * Called in case the task @p isn't fully descheduled from its runqueue,
+ * in this case we must do a remote wakeup. Its a 'light' wakeup though,
+ * since all we need to do is flip p->state to TASK_RUNNING, since
+ * the task is still ->on_rq.
+ */
+static int ttwu_remote(struct task_struct *p, int wake_flags)
+{
+       struct rq *rq;
+       int ret = 0;
+
+       rq = __task_rq_lock(p);
+       if (p->on_rq) {
+               ttwu_do_wakeup(rq, p, wake_flags);
+               ret = 1;
+       }
+       __task_rq_unlock(rq);
+
+       return ret;
+}
+
+#ifdef CONFIG_SMP
+static void sched_ttwu_pending(void)
+{
+       struct rq *rq = this_rq();
+       struct llist_node *llist = llist_del_all(&rq->wake_list);
+       struct task_struct *p;
+
+       raw_spin_lock(&rq->lock);
+
+       while (llist) {
+               p = llist_entry(llist, struct task_struct, wake_entry);
+               llist = llist_next(llist);
+               ttwu_do_activate(rq, p, 0);
+       }
+
+       raw_spin_unlock(&rq->lock);
+}
+
+void scheduler_ipi(void)
+{
+       if (llist_empty(&this_rq()->wake_list) && !got_nohz_idle_kick())
+               return;
+
+       /*
+        * Not all reschedule IPI handlers call irq_enter/irq_exit, since
+        * traditionally all their work was done from the interrupt return
+        * path. Now that we actually do some work, we need to make sure
+        * we do call them.
+        *
+        * Some archs already do call them, luckily irq_enter/exit nest
+        * properly.
+        *
+        * Arguably we should visit all archs and update all handlers,
+        * however a fair share of IPIs are still resched only so this would
+        * somewhat pessimize the simple resched case.
+        */
+       irq_enter();
+       sched_ttwu_pending();
+
+       /*
+        * Check if someone kicked us for doing the nohz idle load balance.
+        */
+       if (unlikely(got_nohz_idle_kick() && !need_resched())) {
+               this_rq()->idle_balance = 1;
+               raise_softirq_irqoff(SCHED_SOFTIRQ);
+       }
+       irq_exit();
+}
+
+static void ttwu_queue_remote(struct task_struct *p, int cpu)
+{
+       if (llist_add(&p->wake_entry, &cpu_rq(cpu)->wake_list))
+               smp_send_reschedule(cpu);
+}
+
+bool cpus_share_cache(int this_cpu, int that_cpu)
+{
+       return per_cpu(sd_llc_id, this_cpu) == per_cpu(sd_llc_id, that_cpu);
+}
+#endif /* CONFIG_SMP */
+
+static void ttwu_queue(struct task_struct *p, int cpu)
+{
+       struct rq *rq = cpu_rq(cpu);
+
+#if defined(CONFIG_SMP)
+       if (sched_feat(TTWU_QUEUE) && !cpus_share_cache(smp_processor_id(), cpu)) {
+               sched_clock_cpu(cpu); /* sync clocks x-cpu */
+               ttwu_queue_remote(p, cpu);
+               return;
+       }
+#endif
+
+       raw_spin_lock(&rq->lock);
+       ttwu_do_activate(rq, p, 0);
+       raw_spin_unlock(&rq->lock);
+}
+
+/**
+ * try_to_wake_up - wake up a thread
+ * @p: the thread to be awakened
+ * @state: the mask of task states that can be woken
+ * @wake_flags: wake modifier flags (WF_*)
+ *
+ * Put it on the run-queue if it's not already there. The "current"
+ * thread is always on the run-queue (except when the actual
+ * re-schedule is in progress), and as such you're allowed to do
+ * the simpler "current->state = TASK_RUNNING" to mark yourself
+ * runnable without the overhead of this.
+ *
+ * Returns %true if @p was woken up, %false if it was already running
+ * or @state didn't match @p's state.
+ */
+static int
+try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags)
+{
+       unsigned long flags;
+       int cpu, success = 0;
+
+       smp_wmb();
+       raw_spin_lock_irqsave(&p->pi_lock, flags);
+       if (!(p->state & state))
+               goto out;
+
+       success = 1; /* we're going to change ->state */
+       cpu = task_cpu(p);
+
+       if (p->on_rq && ttwu_remote(p, wake_flags))
+               goto stat;
+
+#ifdef CONFIG_SMP
+       /*
+        * If the owning (remote) cpu is still in the middle of schedule() with
+        * this task as prev, wait until its done referencing the task.
+        */
+       while (p->on_cpu)
+               cpu_relax();
+       /*
+        * Pairs with the smp_wmb() in finish_lock_switch().
+        */
+       smp_rmb();
+
+       p->sched_contributes_to_load = !!task_contributes_to_load(p);
+       p->state = TASK_WAKING;
+
+       if (p->sched_class->task_waking)
+               p->sched_class->task_waking(p);
+
+       cpu = select_task_rq(p, SD_BALANCE_WAKE, wake_flags);
+       if (task_cpu(p) != cpu) {
+               wake_flags |= WF_MIGRATED;
+               set_task_cpu(p, cpu);
+       }
+#endif /* CONFIG_SMP */
+
+       ttwu_queue(p, cpu);
+stat:
+       ttwu_stat(p, cpu, wake_flags);
+out:
+       raw_spin_unlock_irqrestore(&p->pi_lock, flags);
+
+       return success;
+}
+
+/**
+ * try_to_wake_up_local - try to wake up a local task with rq lock held
+ * @p: the thread to be awakened
+ *
+ * Put @p on the run-queue if it's not already there. The caller must
+ * ensure that this_rq() is locked, @p is bound to this_rq() and not
+ * the current task.
+ */
+static void try_to_wake_up_local(struct task_struct *p)
+{
+       struct rq *rq = task_rq(p);
+
+       if (WARN_ON_ONCE(rq != this_rq()) ||
+           WARN_ON_ONCE(p == current))
+               return;
+
+       lockdep_assert_held(&rq->lock);
+
+       if (!raw_spin_trylock(&p->pi_lock)) {
+               raw_spin_unlock(&rq->lock);
+               raw_spin_lock(&p->pi_lock);
+               raw_spin_lock(&rq->lock);
+       }
+
+       if (!(p->state & TASK_NORMAL))
+               goto out;
+
+       if (!p->on_rq)
+               ttwu_activate(rq, p, ENQUEUE_WAKEUP);
+
+       ttwu_do_wakeup(rq, p, 0);
+       ttwu_stat(p, smp_processor_id(), 0);
+out:
+       raw_spin_unlock(&p->pi_lock);
+}
+
+/**
+ * wake_up_process - Wake up a specific process
+ * @p: The process to be woken up.
+ *
+ * Attempt to wake up the nominated process and move it to the set of runnable
+ * processes.  Returns 1 if the process was woken up, 0 if it was already
+ * running.
+ *
+ * It may be assumed that this function implies a write memory barrier before
+ * changing the task state if and only if any tasks are woken up.
+ */
+int wake_up_process(struct task_struct *p)
+{
+       WARN_ON(task_is_stopped_or_traced(p));
+       return try_to_wake_up(p, TASK_NORMAL, 0);
+}
+EXPORT_SYMBOL(wake_up_process);
+
+int wake_up_state(struct task_struct *p, unsigned int state)
+{
+       return try_to_wake_up(p, state, 0);
+}
+
+/*
+ * Perform scheduler related setup for a newly forked process p.
+ * p is forked by current.
+ *
+ * __sched_fork() is basic setup used by init_idle() too:
+ */
+static void __sched_fork(struct task_struct *p)
+{
+       p->on_rq                        = 0;
+
+       p->se.on_rq                     = 0;
+       p->se.exec_start                = 0;
+       p->se.sum_exec_runtime          = 0;
+       p->se.prev_sum_exec_runtime     = 0;
+       p->se.nr_migrations             = 0;
+       p->se.vruntime                  = 0;
+       INIT_LIST_HEAD(&p->se.group_node);
+
+/*
+ * Load-tracking only depends on SMP, FAIR_GROUP_SCHED dependency below may be
+ * removed when useful for applications beyond shares distribution (e.g.
+ * load-balance).
+ */
+#if defined(CONFIG_SMP) && defined(CONFIG_FAIR_GROUP_SCHED)
+       p->se.avg.runnable_avg_period = 0;
+       p->se.avg.runnable_avg_sum = 0;
+#endif
+#ifdef CONFIG_SCHEDSTATS
+       memset(&p->se.statistics, 0, sizeof(p->se.statistics));
+#endif
+
+       INIT_LIST_HEAD(&p->rt.run_list);
+
+#ifdef CONFIG_PREEMPT_NOTIFIERS
+       INIT_HLIST_HEAD(&p->preempt_notifiers);
+#endif
+
+#ifdef CONFIG_NUMA_BALANCING
+       if (p->mm && atomic_read(&p->mm->mm_users) == 1) {
+               p->mm->numa_next_scan = jiffies;
+               p->mm->numa_next_reset = jiffies;
+               p->mm->numa_scan_seq = 0;
+       }
+
+       p->node_stamp = 0ULL;
+       p->numa_scan_seq = p->mm ? p->mm->numa_scan_seq : 0;
+       p->numa_migrate_seq = p->mm ? p->mm->numa_scan_seq - 1 : 0;
+       p->numa_scan_period = sysctl_numa_balancing_scan_delay;
+       p->numa_work.next = &p->numa_work;
+#endif /* CONFIG_NUMA_BALANCING */
+}
+
+#ifdef CONFIG_NUMA_BALANCING
+#ifdef CONFIG_SCHED_DEBUG
+void set_numabalancing_state(bool enabled)
+{
+       if (enabled)
+               sched_feat_set("NUMA");
+       else
+               sched_feat_set("NO_NUMA");
+}
+#else
+__read_mostly bool numabalancing_enabled;
+
+void set_numabalancing_state(bool enabled)
+{
+       numabalancing_enabled = enabled;
+}
+#endif /* CONFIG_SCHED_DEBUG */
+#endif /* CONFIG_NUMA_BALANCING */
+
+/*
+ * fork()/clone()-time setup:
+ */
+void sched_fork(struct task_struct *p)
+{
+       unsigned long flags;
+       int cpu = get_cpu();
+
+       __sched_fork(p);
+       /*
+        * We mark the process as running here. This guarantees that
+        * nobody will actually run it, and a signal or other external
+        * event cannot wake it up and insert it on the runqueue either.
+        */
+       p->state = TASK_RUNNING;
+
+       /*
+        * Make sure we do not leak PI boosting priority to the child.
+        */
+       p->prio = current->normal_prio;
+
+       /*
+        * Revert to default priority/policy on fork if requested.
+        */
+       if (unlikely(p->sched_reset_on_fork)) {
+               if (task_has_rt_policy(p)) {
+                       p->policy = SCHED_NORMAL;
+                       p->static_prio = NICE_TO_PRIO(0);
+                       p->rt_priority = 0;
+               } else if (PRIO_TO_NICE(p->static_prio) < 0)
+                       p->static_prio = NICE_TO_PRIO(0);
+
+               p->prio = p->normal_prio = __normal_prio(p);
+               set_load_weight(p);
+
+               /*
+                * We don't need the reset flag anymore after the fork. It has
+                * fulfilled its duty:
+                */
+               p->sched_reset_on_fork = 0;
+       }
+
+       if (!rt_prio(p->prio))
+               p->sched_class = &fair_sched_class;
+
+       if (p->sched_class->task_fork)
+               p->sched_class->task_fork(p);
+
+       /*
+        * The child is not yet in the pid-hash so no cgroup attach races,
+        * and the cgroup is pinned to this child due to cgroup_fork()
+        * is ran before sched_fork().
+        *
+        * Silence PROVE_RCU.
+        */
+       raw_spin_lock_irqsave(&p->pi_lock, flags);
+       set_task_cpu(p, cpu);
+       raw_spin_unlock_irqrestore(&p->pi_lock, flags);
+
+#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
+       if (likely(sched_info_on()))
+               memset(&p->sched_info, 0, sizeof(p->sched_info));
+#endif
+#if defined(CONFIG_SMP)
+       p->on_cpu = 0;
+#endif
+#ifdef CONFIG_PREEMPT_COUNT
+       /* Want to start with kernel preemption disabled. */
+       task_thread_info(p)->preempt_count = 1;
+#endif
+#ifdef CONFIG_SMP
+       plist_node_init(&p->pushable_tasks, MAX_PRIO);
+#endif
+
+       put_cpu();
+}
+
+/*
+ * wake_up_new_task - wake up a newly created task for the first time.
+ *
+ * This function will do some initial scheduler statistics housekeeping
+ * that must be done for every newly created context, then puts the task
+ * on the runqueue and wakes it.
+ */
+void wake_up_new_task(struct task_struct *p)
+{
+       unsigned long flags;
+       struct rq *rq;
+
+       raw_spin_lock_irqsave(&p->pi_lock, flags);
+#ifdef CONFIG_SMP
+       /*
+        * Fork balancing, do it here and not earlier because:
+        *  - cpus_allowed can change in the fork path
+        *  - any previously selected cpu might disappear through hotplug
+        */
+       set_task_cpu(p, select_task_rq(p, SD_BALANCE_FORK, 0));
+#endif
+
+       rq = __task_rq_lock(p);
+       activate_task(rq, p, 0);
+       p->on_rq = 1;
+       trace_sched_wakeup_new(p, true);
+       check_preempt_curr(rq, p, WF_FORK);
+#ifdef CONFIG_SMP
+       if (p->sched_class->task_woken)
+               p->sched_class->task_woken(rq, p);
+#endif
+       task_rq_unlock(rq, p, &flags);
+}
+
+#ifdef CONFIG_PREEMPT_NOTIFIERS
+
+/**
+ * preempt_notifier_register - tell me when current is being preempted & rescheduled
+ * @notifier: notifier struct to register
+ */
+void preempt_notifier_register(struct preempt_notifier *notifier)
+{
+       hlist_add_head(&notifier->link, &current->preempt_notifiers);
+}
+EXPORT_SYMBOL_GPL(preempt_notifier_register);
+
+/**
+ * preempt_notifier_unregister - no longer interested in preemption notifications
+ * @notifier: notifier struct to unregister
+ *
+ * This is safe to call from within a preemption notifier.
+ */
+void preempt_notifier_unregister(struct preempt_notifier *notifier)
+{
+       hlist_del(&notifier->link);
+}
+EXPORT_SYMBOL_GPL(preempt_notifier_unregister);
+
+static void fire_sched_in_preempt_notifiers(struct task_struct *curr)
+{
+       struct preempt_notifier *notifier;
+
+       hlist_for_each_entry(notifier, &curr->preempt_notifiers, link)
+               notifier->ops->sched_in(notifier, raw_smp_processor_id());
+}
+
+static void
+fire_sched_out_preempt_notifiers(struct task_struct *curr,
+                                struct task_struct *next)
+{
+       struct preempt_notifier *notifier;
+
+       hlist_for_each_entry(notifier, &curr->preempt_notifiers, link)
+               notifier->ops->sched_out(notifier, next);
+}
+
+#else /* !CONFIG_PREEMPT_NOTIFIERS */
+
+static void fire_sched_in_preempt_notifiers(struct task_struct *curr)
+{
+}
+
+static void
+fire_sched_out_preempt_notifiers(struct task_struct *curr,
+                                struct task_struct *next)
+{
+}
+
+#endif /* CONFIG_PREEMPT_NOTIFIERS */
+
+/**
+ * prepare_task_switch - prepare to switch tasks
+ * @rq: the runqueue preparing to switch
+ * @prev: the current task that is being switched out
+ * @next: the task we are going to switch to.
+ *
+ * This is called with the rq lock held and interrupts off. It must
+ * be paired with a subsequent finish_task_switch after the context
+ * switch.
+ *
+ * prepare_task_switch sets up locking and calls architecture specific
+ * hooks.
+ */
+static inline void
+prepare_task_switch(struct rq *rq, struct task_struct *prev,
+                   struct task_struct *next)
+{
+       trace_sched_switch(prev, next);
+       sched_info_switch(prev, next);
+       perf_event_task_sched_out(prev, next);
+       fire_sched_out_preempt_notifiers(prev, next);
+       prepare_lock_switch(rq, next);
+       prepare_arch_switch(next);
+}
+
+/**
+ * finish_task_switch - clean up after a task-switch
+ * @rq: runqueue associated with task-switch
+ * @prev: the thread we just switched away from.
+ *
+ * finish_task_switch must be called after the context switch, paired
+ * with a prepare_task_switch call before the context switch.
+ * finish_task_switch will reconcile locking set up by prepare_task_switch,
+ * and do any other architecture-specific cleanup actions.
+ *
+ * Note that we may have delayed dropping an mm in context_switch(). If
+ * so, we finish that here outside of the runqueue lock. (Doing it
+ * with the lock held can cause deadlocks; see schedule() for
+ * details.)
+ */
+static void finish_task_switch(struct rq *rq, struct task_struct *prev)
+       __releases(rq->lock)
+{
+       struct mm_struct *mm = rq->prev_mm;
+       long prev_state;
+
+       rq->prev_mm = NULL;
+
+       /*
+        * A task struct has one reference for the use as "current".
+        * If a task dies, then it sets TASK_DEAD in tsk->state and calls
+        * schedule one last time. The schedule call will never return, and
+        * the scheduled task must drop that reference.
+        * The test for TASK_DEAD must occur while the runqueue locks are
+        * still held, otherwise prev could be scheduled on another cpu, die
+        * there before we look at prev->state, and then the reference would
+        * be dropped twice.
+        *              Manfred Spraul <manfred@colorfullife.com>
+        */
+       prev_state = prev->state;
+       vtime_task_switch(prev);
+       finish_arch_switch(prev);
+       perf_event_task_sched_in(prev, current);
+       finish_lock_switch(rq, prev);
+       finish_arch_post_lock_switch();
+
+       fire_sched_in_preempt_notifiers(current);
+       if (mm)
+               mmdrop(mm);
+       if (unlikely(prev_state == TASK_DEAD)) {
+               /*
+                * Remove function-return probe instances associated with this
+                * task and put them back on the free list.
+                */
+               kprobe_flush_task(prev);
+               put_task_struct(prev);
+       }
+}
+
+#ifdef CONFIG_SMP
+
+/* assumes rq->lock is held */
+static inline void pre_schedule(struct rq *rq, struct task_struct *prev)
+{
+       if (prev->sched_class->pre_schedule)
+               prev->sched_class->pre_schedule(rq, prev);
+}
+
+/* rq->lock is NOT held, but preemption is disabled */
+static inline void post_schedule(struct rq *rq)
+{
+       if (rq->post_schedule) {
+               unsigned long flags;
+
+               raw_spin_lock_irqsave(&rq->lock, flags);
+               if (rq->curr->sched_class->post_schedule)
+                       rq->curr->sched_class->post_schedule(rq);
+               raw_spin_unlock_irqrestore(&rq->lock, flags);
+
+               rq->post_schedule = 0;
+       }
+}
+
+#else
+
+static inline void pre_schedule(struct rq *rq, struct task_struct *p)
+{
+}
+
+static inline void post_schedule(struct rq *rq)
+{
+}
+
+#endif
+
+/**
+ * schedule_tail - first thing a freshly forked thread must call.
+ * @prev: the thread we just switched away from.
+ */
+asmlinkage void schedule_tail(struct task_struct *prev)
+       __releases(rq->lock)
+{
+       struct rq *rq = this_rq();
+
+       finish_task_switch(rq, prev);
+
+       /*
+        * FIXME: do we need to worry about rq being invalidated by the
+        * task_switch?
+        */
+       post_schedule(rq);
+
+#ifdef __ARCH_WANT_UNLOCKED_CTXSW
+       /* In this case, finish_task_switch does not reenable preemption */
+       preempt_enable();
+#endif
+       if (current->set_child_tid)
+               put_user(task_pid_vnr(current), current->set_child_tid);
+}
+
+/*
+ * context_switch - switch to the new MM and the new
+ * thread's register state.
+ */
+static inline void
+context_switch(struct rq *rq, struct task_struct *prev,
+              struct task_struct *next)
+{
+       struct mm_struct *mm, *oldmm;
+
+       prepare_task_switch(rq, prev, next);
+
+       mm = next->mm;
+       oldmm = prev->active_mm;
+       /*
+        * For paravirt, this is coupled with an exit in switch_to to
+        * combine the page table reload and the switch backend into
+        * one hypercall.
+        */
+       arch_start_context_switch(prev);
+
+       if (!mm) {
+               next->active_mm = oldmm;
+               atomic_inc(&oldmm->mm_count);
+               enter_lazy_tlb(oldmm, next);
+       } else
+               switch_mm(oldmm, mm, next);
+
+       if (!prev->mm) {
+               prev->active_mm = NULL;
+               rq->prev_mm = oldmm;
+       }
+       /*
+        * Since the runqueue lock will be released by the next
+        * task (which is an invalid locking op but in the case
+        * of the scheduler it's an obvious special-case), so we
+        * do an early lockdep release here:
+        */
+#ifndef __ARCH_WANT_UNLOCKED_CTXSW
+       spin_release(&rq->lock.dep_map, 1, _THIS_IP_);
+#endif
+
+       context_tracking_task_switch(prev, next);
+       /* Here we just switch the register state and the stack. */
+       switch_to(prev, next, prev);
+
+       barrier();
+       /*
+        * this_rq must be evaluated again because prev may have moved
+        * CPUs since it called schedule(), thus the 'rq' on its stack
+        * frame will be invalid.
+        */
+       finish_task_switch(this_rq(), prev);
+}
+
+/*
+ * nr_running and nr_context_switches:
+ *
+ * externally visible scheduler statistics: current number of runnable
+ * threads, total number of context switches performed since bootup.
+ */
+unsigned long nr_running(void)
+{
+       unsigned long i, sum = 0;
+
+       for_each_online_cpu(i)
+               sum += cpu_rq(i)->nr_running;
+
+       return sum;
+}
+
+unsigned long long nr_context_switches(void)
+{
+       int i;
+       unsigned long long sum = 0;
+
+       for_each_possible_cpu(i)
+               sum += cpu_rq(i)->nr_switches;
+
+       return sum;
+}
+
+unsigned long nr_iowait(void)
+{
+       unsigned long i, sum = 0;
+
+       for_each_possible_cpu(i)
+               sum += atomic_read(&cpu_rq(i)->nr_iowait);
+
+       return sum;
+}
+
+unsigned long nr_iowait_cpu(int cpu)
+{
+       struct rq *this = cpu_rq(cpu);
+       return atomic_read(&this->nr_iowait);
+}
+
+unsigned long this_cpu_load(void)
+{
+       struct rq *this = this_rq();
+       return this->cpu_load[0];
+}
+
+
+/*
+ * Global load-average calculations
+ *
+ * We take a distributed and async approach to calculating the global load-avg
+ * in order to minimize overhead.
+ *
+ * The global load average is an exponentially decaying average of nr_running +
+ * nr_uninterruptible.
+ *
+ * Once every LOAD_FREQ:
+ *
+ *   nr_active = 0;
+ *   for_each_possible_cpu(cpu)
+ *     nr_active += cpu_of(cpu)->nr_running + cpu_of(cpu)->nr_uninterruptible;
+ *
+ *   avenrun[n] = avenrun[0] * exp_n + nr_active * (1 - exp_n)
+ *
+ * Due to a number of reasons the above turns in the mess below:
+ *
+ *  - for_each_possible_cpu() is prohibitively expensive on machines with
+ *    serious number of cpus, therefore we need to take a distributed approach
+ *    to calculating nr_active.
+ *
+ *        \Sum_i x_i(t) = \Sum_i x_i(t) - x_i(t_0) | x_i(t_0) := 0
+ *                      = \Sum_i { \Sum_j=1 x_i(t_j) - x_i(t_j-1) }
+ *
+ *    So assuming nr_active := 0 when we start out -- true per definition, we
+ *    can simply take per-cpu deltas and fold those into a global accumulate
+ *    to obtain the same result. See calc_load_fold_active().
+ *
+ *    Furthermore, in order to avoid synchronizing all per-cpu delta folding
+ *    across the machine, we assume 10 ticks is sufficient time for every
+ *    cpu to have completed this task.
+ *
+ *    This places an upper-bound on the IRQ-off latency of the machine. Then
+ *    again, being late doesn't loose the delta, just wrecks the sample.
+ *
+ *  - cpu_rq()->nr_uninterruptible isn't accurately tracked per-cpu because
+ *    this would add another cross-cpu cacheline miss and atomic operation
+ *    to the wakeup path. Instead we increment on whatever cpu the task ran
+ *    when it went into uninterruptible state and decrement on whatever cpu
+ *    did the wakeup. This means that only the sum of nr_uninterruptible over
+ *    all cpus yields the correct result.
+ *
+ *  This covers the NO_HZ=n code, for extra head-aches, see the comment below.
+ */
+
+/* Variables and functions for calc_load */
+static atomic_long_t calc_load_tasks;
+static unsigned long calc_load_update;
+unsigned long avenrun[3];
+EXPORT_SYMBOL(avenrun); /* should be removed */
+
+/**
+ * get_avenrun - get the load average array
+ * @loads:     pointer to dest load array
+ * @offset:    offset to add
+ * @shift:     shift count to shift the result left
+ *
+ * These values are estimates at best, so no need for locking.
+ */
+void get_avenrun(unsigned long *loads, unsigned long offset, int shift)
+{
+       loads[0] = (avenrun[0] + offset) << shift;
+       loads[1] = (avenrun[1] + offset) << shift;
+       loads[2] = (avenrun[2] + offset) << shift;
+}
+
+static long calc_load_fold_active(struct rq *this_rq)
+{
+       long nr_active, delta = 0;
+
+       nr_active = this_rq->nr_running;
+       nr_active += (long) this_rq->nr_uninterruptible;
+
+       if (nr_active != this_rq->calc_load_active) {
+               delta = nr_active - this_rq->calc_load_active;
+               this_rq->calc_load_active = nr_active;
+       }
+
+       return delta;
+}
+
+/*
+ * a1 = a0 * e + a * (1 - e)
+ */
+static unsigned long
+calc_load(unsigned long load, unsigned long exp, unsigned long active)
+{
+       load *= exp;
+       load += active * (FIXED_1 - exp);
+       load += 1UL << (FSHIFT - 1);
+       return load >> FSHIFT;
+}
+
+#ifdef CONFIG_NO_HZ
+/*
+ * Handle NO_HZ for the global load-average.
+ *
+ * Since the above described distributed algorithm to compute the global
+ * load-average relies on per-cpu sampling from the tick, it is affected by
+ * NO_HZ.
+ *
+ * The basic idea is to fold the nr_active delta into a global idle-delta upon
+ * entering NO_HZ state such that we can include this as an 'extra' cpu delta
+ * when we read the global state.
+ *
+ * Obviously reality has to ruin such a delightfully simple scheme:
+ *
+ *  - When we go NO_HZ idle during the window, we can negate our sample
+ *    contribution, causing under-accounting.
+ *
+ *    We avoid this by keeping two idle-delta counters and flipping them
+ *    when the window starts, thus separating old and new NO_HZ load.
+ *
+ *    The only trick is the slight shift in index flip for read vs write.
+ *
+ *        0s            5s            10s           15s
+ *          +10           +10           +10           +10
+ *        |-|-----------|-|-----------|-|-----------|-|
+ *    r:0 0 1           1 0           0 1           1 0
+ *    w:0 1 1           0 0           1 1           0 0
+ *
+ *    This ensures we'll fold the old idle contribution in this window while
+ *    accumlating the new one.
+ *
+ *  - When we wake up from NO_HZ idle during the window, we push up our
+ *    contribution, since we effectively move our sample point to a known
+ *    busy state.
+ *
+ *    This is solved by pushing the window forward, and thus skipping the
+ *    sample, for this cpu (effectively using the idle-delta for this cpu which
+ *    was in effect at the time the window opened). This also solves the issue
+ *    of having to deal with a cpu having been in NOHZ idle for multiple
+ *    LOAD_FREQ intervals.
+ *
+ * When making the ILB scale, we should try to pull this in as well.
+ */
+static atomic_long_t calc_load_idle[2];
+static int calc_load_idx;
+
+static inline int calc_load_write_idx(void)
+{
+       int idx = calc_load_idx;
+
+       /*
+        * See calc_global_nohz(), if we observe the new index, we also
+        * need to observe the new update time.
+        */
+       smp_rmb();
+
+       /*
+        * If the folding window started, make sure we start writing in the
+        * next idle-delta.
+        */
+       if (!time_before(jiffies, calc_load_update))
+               idx++;
+
+       return idx & 1;
+}
+
+static inline int calc_load_read_idx(void)
+{
+       return calc_load_idx & 1;
+}
+
+void calc_load_enter_idle(void)
+{
+       struct rq *this_rq = this_rq();
+       long delta;
+
+       /*
+        * We're going into NOHZ mode, if there's any pending delta, fold it
+        * into the pending idle delta.
+        */
+       delta = calc_load_fold_active(this_rq);
+       if (delta) {
+               int idx = calc_load_write_idx();
+               atomic_long_add(delta, &calc_load_idle[idx]);
+       }
+}
+
+void calc_load_exit_idle(void)
+{
+       struct rq *this_rq = this_rq();
+
+       /*
+        * If we're still before the sample window, we're done.
+        */
+       if (time_before(jiffies, this_rq->calc_load_update))
+               return;
+
+       /*
+        * We woke inside or after the sample window, this means we're already
+        * accounted through the nohz accounting, so skip the entire deal and
+        * sync up for the next window.
+        */
+       this_rq->calc_load_update = calc_load_update;
+       if (time_before(jiffies, this_rq->calc_load_update + 10))
+               this_rq->calc_load_update += LOAD_FREQ;
+}
+
+static long calc_load_fold_idle(void)
+{
+       int idx = calc_load_read_idx();
+       long delta = 0;
+
+       if (atomic_long_read(&calc_load_idle[idx]))
+               delta = atomic_long_xchg(&calc_load_idle[idx], 0);
+
+       return delta;
+}
+
+/**
+ * fixed_power_int - compute: x^n, in O(log n) time
+ *
+ * @x:         base of the power
+ * @frac_bits: fractional bits of @x
+ * @n:         power to raise @x to.
+ *
+ * By exploiting the relation between the definition of the natural power
+ * function: x^n := x*x*...*x (x multiplied by itself for n times), and
+ * the binary encoding of numbers used by computers: n := \Sum n_i * 2^i,
+ * (where: n_i \elem {0, 1}, the binary vector representing n),
+ * we find: x^n := x^(\Sum n_i * 2^i) := \Prod x^(n_i * 2^i), which is
+ * of course trivially computable in O(log_2 n), the length of our binary
+ * vector.
+ */
+static unsigned long
+fixed_power_int(unsigned long x, unsigned int frac_bits, unsigned int n)
+{
+       unsigned long result = 1UL << frac_bits;
+
+       if (n) for (;;) {
+               if (n & 1) {
+                       result *= x;
+                       result += 1UL << (frac_bits - 1);
+                       result >>= frac_bits;
+               }
+               n >>= 1;
+               if (!n)
+                       break;
+               x *= x;
+               x += 1UL << (frac_bits - 1);
+               x >>= frac_bits;
+       }
+
+       return result;
+}
+
+/*
+ * a1 = a0 * e + a * (1 - e)
+ *
+ * a2 = a1 * e + a * (1 - e)
+ *    = (a0 * e + a * (1 - e)) * e + a * (1 - e)
+ *    = a0 * e^2 + a * (1 - e) * (1 + e)
+ *
+ * a3 = a2 * e + a * (1 - e)
+ *    = (a0 * e^2 + a * (1 - e) * (1 + e)) * e + a * (1 - e)
+ *    = a0 * e^3 + a * (1 - e) * (1 + e + e^2)
+ *
+ *  ...
+ *
+ * an = a0 * e^n + a * (1 - e) * (1 + e + ... + e^n-1) [1]
+ *    = a0 * e^n + a * (1 - e) * (1 - e^n)/(1 - e)
+ *    = a0 * e^n + a * (1 - e^n)
+ *
+ * [1] application of the geometric series:
+ *
+ *              n         1 - x^(n+1)
+ *     S_n := \Sum x^i = -------------
+ *             i=0          1 - x
+ */
+static unsigned long
+calc_load_n(unsigned long load, unsigned long exp,
+           unsigned long active, unsigned int n)
+{
+
+       return calc_load(load, fixed_power_int(exp, FSHIFT, n), active);
+}
+
+/*
+ * NO_HZ can leave us missing all per-cpu ticks calling
+ * calc_load_account_active(), but since an idle CPU folds its delta into
+ * calc_load_tasks_idle per calc_load_account_idle(), all we need to do is fold
+ * in the pending idle delta if our idle period crossed a load cycle boundary.
+ *
+ * Once we've updated the global active value, we need to apply the exponential
+ * weights adjusted to the number of cycles missed.
+ */
+static void calc_global_nohz(void)
+{
+       long delta, active, n;
+
+       if (!time_before(jiffies, calc_load_update + 10)) {
+               /*
+                * Catch-up, fold however many we are behind still
+                */
+               delta = jiffies - calc_load_update - 10;
+               n = 1 + (delta / LOAD_FREQ);
+
+               active = atomic_long_read(&calc_load_tasks);
+               active = active > 0 ? active * FIXED_1 : 0;
+
+               avenrun[0] = calc_load_n(avenrun[0], EXP_1, active, n);
+               avenrun[1] = calc_load_n(avenrun[1], EXP_5, active, n);
+               avenrun[2] = calc_load_n(avenrun[2], EXP_15, active, n);
+
+               calc_load_update += n * LOAD_FREQ;
+       }
+
+       /*
+        * Flip the idle index...
+        *
+        * Make sure we first write the new time then flip the index, so that
+        * calc_load_write_idx() will see the new time when it reads the new
+        * index, this avoids a double flip messing things up.
+        */
+       smp_wmb();
+       calc_load_idx++;
+}
+#else /* !CONFIG_NO_HZ */
+
+static inline long calc_load_fold_idle(void) { return 0; }
+static inline void calc_global_nohz(void) { }
+
+#endif /* CONFIG_NO_HZ */
+
+/*
+ * calc_load - update the avenrun load estimates 10 ticks after the
+ * CPUs have updated calc_load_tasks.
+ */
+void calc_global_load(unsigned long ticks)
+{
+       long active, delta;
+
+       if (time_before(jiffies, calc_load_update + 10))
+               return;
+
+       /*
+        * Fold the 'old' idle-delta to include all NO_HZ cpus.
+        */
+       delta = calc_load_fold_idle();
+       if (delta)
+               atomic_long_add(delta, &calc_load_tasks);
+
+       active = atomic_long_read(&calc_load_tasks);
+       active = active > 0 ? active * FIXED_1 : 0;
+
+       avenrun[0] = calc_load(avenrun[0], EXP_1, active);
+       avenrun[1] = calc_load(avenrun[1], EXP_5, active);
+       avenrun[2] = calc_load(avenrun[2], EXP_15, active);
+
+       calc_load_update += LOAD_FREQ;
+
+       /*
+        * In case we idled for multiple LOAD_FREQ intervals, catch up in bulk.
+        */
+       calc_global_nohz();
+}
+
+/*
+ * Called from update_cpu_load() to periodically update this CPU's
+ * active count.
+ */
+static void calc_load_account_active(struct rq *this_rq)
+{
+       long delta;
+
+       if (time_before(jiffies, this_rq->calc_load_update))
+               return;
+
+       delta  = calc_load_fold_active(this_rq);
+       if (delta)
+               atomic_long_add(delta, &calc_load_tasks);
+
+       this_rq->calc_load_update += LOAD_FREQ;
+}
+
+/*
+ * End of global load-average stuff
+ */
+
+/*
+ * The exact cpuload at various idx values, calculated at every tick would be
+ * load = (2^idx - 1) / 2^idx * load + 1 / 2^idx * cur_load
+ *
+ * If a cpu misses updates for n-1 ticks (as it was idle) and update gets called
+ * on nth tick when cpu may be busy, then we have:
+ * load = ((2^idx - 1) / 2^idx)^(n-1) * load
+ * load = (2^idx - 1) / 2^idx) * load + 1 / 2^idx * cur_load
+ *
+ * decay_load_missed() below does efficient calculation of
+ * load = ((2^idx - 1) / 2^idx)^(n-1) * load
+ * avoiding 0..n-1 loop doing load = ((2^idx - 1) / 2^idx) * load
+ *
+ * The calculation is approximated on a 128 point scale.
+ * degrade_zero_ticks is the number of ticks after which load at any
+ * particular idx is approximated to be zero.
+ * degrade_factor is a precomputed table, a row for each load idx.
+ * Each column corresponds to degradation factor for a power of two ticks,
+ * based on 128 point scale.
+ * Example:
+ * row 2, col 3 (=12) says that the degradation at load idx 2 after
+ * 8 ticks is 12/128 (which is an approximation of exact factor 3^8/4^8).
+ *
+ * With this power of 2 load factors, we can degrade the load n times
+ * by looking at 1 bits in n and doing as many mult/shift instead of
+ * n mult/shifts needed by the exact degradation.
+ */
+#define DEGRADE_SHIFT          7
+static const unsigned char
+               degrade_zero_ticks[CPU_LOAD_IDX_MAX] = {0, 8, 32, 64, 128};
+static const unsigned char
+               degrade_factor[CPU_LOAD_IDX_MAX][DEGRADE_SHIFT + 1] = {
+                                       {0, 0, 0, 0, 0, 0, 0, 0},
+                                       {64, 32, 8, 0, 0, 0, 0, 0},
+                                       {96, 72, 40, 12, 1, 0, 0},
+                                       {112, 98, 75, 43, 15, 1, 0},
+                                       {120, 112, 98, 76, 45, 16, 2} };
+
+/*
+ * Update cpu_load for any missed ticks, due to tickless idle. The backlog
+ * would be when CPU is idle and so we just decay the old load without
+ * adding any new load.
+ */
+static unsigned long
+decay_load_missed(unsigned long load, unsigned long missed_updates, int idx)
+{
+       int j = 0;
+
+       if (!missed_updates)
+               return load;
+
+       if (missed_updates >= degrade_zero_ticks[idx])
+               return 0;
+
+       if (idx == 1)
+               return load >> missed_updates;
+
+       while (missed_updates) {
+               if (missed_updates % 2)
+                       load = (load * degrade_factor[idx][j]) >> DEGRADE_SHIFT;
+
+               missed_updates >>= 1;
+               j++;
+       }
+       return load;
+}
+
+/*
+ * Update rq->cpu_load[] statistics. This function is usually called every
+ * scheduler tick (TICK_NSEC). With tickless idle this will not be called
+ * every tick. We fix it up based on jiffies.
+ */
+static void __update_cpu_load(struct rq *this_rq, unsigned long this_load,
+                             unsigned long pending_updates)
+{
+       int i, scale;
+
+       this_rq->nr_load_updates++;
+
+       /* Update our load: */
+       this_rq->cpu_load[0] = this_load; /* Fasttrack for idx 0 */
+       for (i = 1, scale = 2; i < CPU_LOAD_IDX_MAX; i++, scale += scale) {
+               unsigned long old_load, new_load;
+
+               /* scale is effectively 1 << i now, and >> i divides by scale */
+
+               old_load = this_rq->cpu_load[i];
+               old_load = decay_load_missed(old_load, pending_updates - 1, i);
+               new_load = this_load;
+               /*
+                * Round up the averaging division if load is increasing. This
+                * prevents us from getting stuck on 9 if the load is 10, for
+                * example.
+                */
+               if (new_load > old_load)
+                       new_load += scale - 1;
+
+               this_rq->cpu_load[i] = (old_load * (scale - 1) + new_load) >> i;
+       }
+
+       sched_avg_update(this_rq);
+}
+
+#ifdef CONFIG_NO_HZ
+/*
+ * There is no sane way to deal with nohz on smp when using jiffies because the
+ * cpu doing the jiffies update might drift wrt the cpu doing the jiffy reading
+ * causing off-by-one errors in observed deltas; {0,2} instead of {1,1}.
+ *
+ * Therefore we cannot use the delta approach from the regular tick since that
+ * would seriously skew the load calculation. However we'll make do for those
+ * updates happening while idle (nohz_idle_balance) or coming out of idle
+ * (tick_nohz_idle_exit).
+ *
+ * This means we might still be one tick off for nohz periods.
+ */
+
+/*
+ * Called from nohz_idle_balance() to update the load ratings before doing the
+ * idle balance.
+ */
+void update_idle_cpu_load(struct rq *this_rq)
+{
+       unsigned long curr_jiffies = ACCESS_ONCE(jiffies);
+       unsigned long load = this_rq->load.weight;
+       unsigned long pending_updates;
+
+       /*
+        * bail if there's load or we're actually up-to-date.
+        */
+       if (load || curr_jiffies == this_rq->last_load_update_tick)
+               return;
+
+       pending_updates = curr_jiffies - this_rq->last_load_update_tick;
+       this_rq->last_load_update_tick = curr_jiffies;
+
+       __update_cpu_load(this_rq, load, pending_updates);
+}
+
+/*
+ * Called from tick_nohz_idle_exit() -- try and fix up the ticks we missed.
+ */
+void update_cpu_load_nohz(void)
+{
+       struct rq *this_rq = this_rq();
+       unsigned long curr_jiffies = ACCESS_ONCE(jiffies);
+       unsigned long pending_updates;
+
+       if (curr_jiffies == this_rq->last_load_update_tick)
+               return;
+
+       raw_spin_lock(&this_rq->lock);
+       pending_updates = curr_jiffies - this_rq->last_load_update_tick;
+       if (pending_updates) {
+               this_rq->last_load_update_tick = curr_jiffies;
+               /*
+                * We were idle, this means load 0, the current load might be
+                * !0 due to remote wakeups and the sort.
+                */
+               __update_cpu_load(this_rq, 0, pending_updates);
+       }
+       raw_spin_unlock(&this_rq->lock);
+}
+#endif /* CONFIG_NO_HZ */
+
+/*
+ * Called from scheduler_tick()
+ */
+static void update_cpu_load_active(struct rq *this_rq)
+{
+       /*
+        * See the mess around update_idle_cpu_load() / update_cpu_load_nohz().
+        */
+       this_rq->last_load_update_tick = jiffies;
+       __update_cpu_load(this_rq, this_rq->load.weight, 1);
+
+       calc_load_account_active(this_rq);
+}
+
+#ifdef CONFIG_SMP
+
+/*
+ * sched_exec - execve() is a valuable balancing opportunity, because at
+ * this point the task has the smallest effective memory and cache footprint.
+ */
+void sched_exec(void)
+{
+       struct task_struct *p = current;
+       unsigned long flags;
+       int dest_cpu;
+
+       raw_spin_lock_irqsave(&p->pi_lock, flags);
+       dest_cpu = p->sched_class->select_task_rq(p, SD_BALANCE_EXEC, 0);
+       if (dest_cpu == smp_processor_id())
+               goto unlock;
+
+       if (likely(cpu_active(dest_cpu))) {
+               struct migration_arg arg = { p, dest_cpu };
+
+               raw_spin_unlock_irqrestore(&p->pi_lock, flags);
+               stop_one_cpu(task_cpu(p), migration_cpu_stop, &arg);
+               return;
+       }
+unlock:
+       raw_spin_unlock_irqrestore(&p->pi_lock, flags);
+}
+
+#endif
+
+DEFINE_PER_CPU(struct kernel_stat, kstat);
+DEFINE_PER_CPU(struct kernel_cpustat, kernel_cpustat);
+
+EXPORT_PER_CPU_SYMBOL(kstat);
+EXPORT_PER_CPU_SYMBOL(kernel_cpustat);
+
+/*
+ * Return any ns on the sched_clock that have not yet been accounted in
+ * @p in case that task is currently running.
+ *
+ * Called with task_rq_lock() held on @rq.
+ */
+static u64 do_task_delta_exec(struct task_struct *p, struct rq *rq)
+{
+       u64 ns = 0;
+
+       if (task_current(rq, p)) {
+               update_rq_clock(rq);
+               ns = rq->clock_task - p->se.exec_start;
+               if ((s64)ns < 0)
+                       ns = 0;
+       }
+
+       return ns;
+}
+
+unsigned long long task_delta_exec(struct task_struct *p)
+{
+       unsigned long flags;
+       struct rq *rq;
+       u64 ns = 0;
+
+       rq = task_rq_lock(p, &flags);
+       ns = do_task_delta_exec(p, rq);
+       task_rq_unlock(rq, p, &flags);
+
+       return ns;
+}
+
+/*
+ * Return accounted runtime for the task.
+ * In case the task is currently running, return the runtime plus current's
+ * pending runtime that have not been accounted yet.
+ */
+unsigned long long task_sched_runtime(struct task_struct *p)
+{
+       unsigned long flags;
+       struct rq *rq;
+       u64 ns = 0;
+
+       rq = task_rq_lock(p, &flags);
+       ns = p->se.sum_exec_runtime + do_task_delta_exec(p, rq);
+       task_rq_unlock(rq, p, &flags);
+
+       return ns;
+}
+
+/*
+ * This function gets called by the timer code, with HZ frequency.
+ * We call it with interrupts disabled.
+ */
+void scheduler_tick(void)
+{
+       int cpu = smp_processor_id();
+       struct rq *rq = cpu_rq(cpu);
+       struct task_struct *curr = rq->curr;
+
+       sched_clock_tick();
+
+       raw_spin_lock(&rq->lock);
+       update_rq_clock(rq);
+       update_cpu_load_active(rq);
+       curr->sched_class->task_tick(rq, curr, 0);
+       raw_spin_unlock(&rq->lock);
+
+       perf_event_task_tick();
+
+#ifdef CONFIG_SMP
+       rq->idle_balance = idle_cpu(cpu);
+       trigger_load_balance(rq, cpu);
+#endif
+}
+
+notrace unsigned long get_parent_ip(unsigned long addr)
+{
+       if (in_lock_functions(addr)) {
+               addr = CALLER_ADDR2;
+               if (in_lock_functions(addr))
+                       addr = CALLER_ADDR3;
+       }
+       return addr;
+}
+
+#if defined(CONFIG_PREEMPT) && (defined(CONFIG_DEBUG_PREEMPT) || \
+                               defined(CONFIG_PREEMPT_TRACER))
+
+void __kprobes add_preempt_count(int val)
+{
+#ifdef CONFIG_DEBUG_PREEMPT
+       /*
+        * Underflow?
+        */
+       if (DEBUG_LOCKS_WARN_ON((preempt_count() < 0)))
+               return;
+#endif
+       preempt_count() += val;
+#ifdef CONFIG_DEBUG_PREEMPT
+       /*
+        * Spinlock count overflowing soon?
+        */
+       DEBUG_LOCKS_WARN_ON((preempt_count() & PREEMPT_MASK) >=
+                               PREEMPT_MASK - 10);
+#endif
+       if (preempt_count() == val)
+               trace_preempt_off(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1));
+}
+EXPORT_SYMBOL(add_preempt_count);
+
+void __kprobes sub_preempt_count(int val)
+{
+#ifdef CONFIG_DEBUG_PREEMPT
+       /*
+        * Underflow?
+        */
+       if (DEBUG_LOCKS_WARN_ON(val > preempt_count()))
+               return;
+       /*
+        * Is the spinlock portion underflowing?
+        */
+       if (DEBUG_LOCKS_WARN_ON((val < PREEMPT_MASK) &&
+                       !(preempt_count() & PREEMPT_MASK)))
+               return;
+#endif
+
+       if (preempt_count() == val)
+               trace_preempt_on(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1));
+       preempt_count() -= val;
+}
+EXPORT_SYMBOL(sub_preempt_count);
+
+#endif
+
+/*
+ * Print scheduling while atomic bug:
+ */
+static noinline void __schedule_bug(struct task_struct *prev)
+{
+       if (oops_in_progress)
+               return;
+
+       printk(KERN_ERR "BUG: scheduling while atomic: %s/%d/0x%08x\n",
+               prev->comm, prev->pid, preempt_count());
+
+       debug_show_held_locks(prev);
+       print_modules();
+       if (irqs_disabled())
+               print_irqtrace_events(prev);
+       dump_stack();
+       add_taint(TAINT_WARN, LOCKDEP_STILL_OK);
+}
+
+/*
+ * Various schedule()-time debugging checks and statistics:
+ */
+static inline void schedule_debug(struct task_struct *prev)
+{
+       /*
+        * Test if we are atomic. Since do_exit() needs to call into
+        * schedule() atomically, we ignore that path for now.
+        * Otherwise, whine if we are scheduling when we should not be.
+        */
+       if (unlikely(in_atomic_preempt_off() && !prev->exit_state))
+               __schedule_bug(prev);
+       rcu_sleep_check();
+
+       profile_hit(SCHED_PROFILING, __builtin_return_address(0));
+
+       schedstat_inc(this_rq(), sched_count);
+}
+
+static void put_prev_task(struct rq *rq, struct task_struct *prev)
+{
+       if (prev->on_rq || rq->skip_clock_update < 0)
+               update_rq_clock(rq);
+       prev->sched_class->put_prev_task(rq, prev);
+}
+
+/*
+ * Pick up the highest-prio task:
+ */
+static inline struct task_struct *
+pick_next_task(struct rq *rq)
+{
+       const struct sched_class *class;
+       struct task_struct *p;
+
+       /*
+        * Optimization: we know that if all tasks are in
+        * the fair class we can call that function directly:
+        */
+       if (likely(rq->nr_running == rq->cfs.h_nr_running)) {
+               p = fair_sched_class.pick_next_task(rq);
+               if (likely(p))
+                       return p;
+       }
+
+       for_each_class(class) {
+               p = class->pick_next_task(rq);
+               if (p)
+                       return p;
+       }
+
+       BUG(); /* the idle class will always have a runnable task */
+}
+
+/*
+ * __schedule() is the main scheduler function.
+ *
+ * The main means of driving the scheduler and thus entering this function are:
+ *
+ *   1. Explicit blocking: mutex, semaphore, waitqueue, etc.
+ *
+ *   2. TIF_NEED_RESCHED flag is checked on interrupt and userspace return
+ *      paths. For example, see arch/x86/entry_64.S.
+ *
+ *      To drive preemption between tasks, the scheduler sets the flag in timer
+ *      interrupt handler scheduler_tick().
+ *
+ *   3. Wakeups don't really cause entry into schedule(). They add a
+ *      task to the run-queue and that's it.
+ *
+ *      Now, if the new task added to the run-queue preempts the current
+ *      task, then the wakeup sets TIF_NEED_RESCHED and schedule() gets
+ *      called on the nearest possible occasion:
+ *
+ *       - If the kernel is preemptible (CONFIG_PREEMPT=y):
+ *
+ *         - in syscall or exception context, at the next outmost
+ *           preempt_enable(). (this might be as soon as the wake_up()'s
+ *           spin_unlock()!)
+ *
+ *         - in IRQ context, return from interrupt-handler to
+ *           preemptible context
+ *
+ *       - If the kernel is not preemptible (CONFIG_PREEMPT is not set)
+ *         then at the next:
+ *
+ *          - cond_resched() call
+ *          - explicit schedule() call
+ *          - return from syscall or exception to user-space
+ *          - return from interrupt-handler to user-space
+ */
+static void __sched __schedule(void)
+{
+       struct task_struct *prev, *next;
+       unsigned long *switch_count;
+       struct rq *rq;
+       int cpu;
+
+need_resched:
+       preempt_disable();
+       cpu = smp_processor_id();
+       rq = cpu_rq(cpu);
+       rcu_note_context_switch(cpu);
+       prev = rq->curr;
+
+       schedule_debug(prev);
+
+       if (sched_feat(HRTICK))
+               hrtick_clear(rq);
+
+       raw_spin_lock_irq(&rq->lock);
+
+       switch_count = &prev->nivcsw;
+       if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) {
+               if (unlikely(signal_pending_state(prev->state, prev))) {
+                       prev->state = TASK_RUNNING;
+               } else {
+                       deactivate_task(rq, prev, DEQUEUE_SLEEP);
+                       prev->on_rq = 0;
+
+                       /*
+                        * If a worker went to sleep, notify and ask workqueue
+                        * whether it wants to wake up a task to maintain
+                        * concurrency.
+                        */
+                       if (prev->flags & PF_WQ_WORKER) {
+                               struct task_struct *to_wakeup;
+
+                               to_wakeup = wq_worker_sleeping(prev, cpu);
+                               if (to_wakeup)
+                                       try_to_wake_up_local(to_wakeup);
+                       }
+               }
+               switch_count = &prev->nvcsw;
+       }
+
+       pre_schedule(rq, prev);
+
+       if (unlikely(!rq->nr_running))
+               idle_balance(cpu, rq);
+
+       put_prev_task(rq, prev);
+       next = pick_next_task(rq);
+       clear_tsk_need_resched(prev);
+       rq->skip_clock_update = 0;
+
+       if (likely(prev != next)) {
+               rq->nr_switches++;
+               rq->curr = next;
+               ++*switch_count;
+
+               context_switch(rq, prev, next); /* unlocks the rq */
+               /*
+                * The context switch have flipped the stack from under us
+                * and restored the local variables which were saved when
+                * this task called schedule() in the past. prev == current
+                * is still correct, but it can be moved to another cpu/rq.
+                */
+               cpu = smp_processor_id();
+               rq = cpu_rq(cpu);
+       } else
+               raw_spin_unlock_irq(&rq->lock);
+
+       post_schedule(rq);
+
+       sched_preempt_enable_no_resched();
+       if (need_resched())
+               goto need_resched;
+}
+
+static inline void sched_submit_work(struct task_struct *tsk)
+{
+       if (!tsk->state || tsk_is_pi_blocked(tsk))
+               return;
+       /*
+        * If we are going to sleep and we have plugged IO queued,
+        * make sure to submit it to avoid deadlocks.
+        */
+       if (blk_needs_flush_plug(tsk))
+               blk_schedule_flush_plug(tsk);
+}
+
+asmlinkage void __sched schedule(void)
+{
+       struct task_struct *tsk = current;
+
+       sched_submit_work(tsk);
+       __schedule();
+}
+EXPORT_SYMBOL(schedule);
+
+#ifdef CONFIG_CONTEXT_TRACKING
+asmlinkage void __sched schedule_user(void)
+{
+       /*
+        * If we come here after a random call to set_need_resched(),
+        * or we have been woken up remotely but the IPI has not yet arrived,
+        * we haven't yet exited the RCU idle mode. Do it here manually until
+        * we find a better solution.
+        */
+       user_exit();
+       schedule();
+       user_enter();
+}
+#endif
+
+/**
+ * schedule_preempt_disabled - called with preemption disabled
+ *
+ * Returns with preemption disabled. Note: preempt_count must be 1
+ */
+void __sched schedule_preempt_disabled(void)
+{
+       sched_preempt_enable_no_resched();
+       schedule();
+       preempt_disable();
+}
+
+#ifdef CONFIG_MUTEX_SPIN_ON_OWNER
+
+static inline bool owner_running(struct mutex *lock, struct task_struct *owner)
+{
+       if (lock->owner != owner)
+               return false;
+
+       /*
+        * Ensure we emit the owner->on_cpu, dereference _after_ checking
+        * lock->owner still matches owner, if that fails, owner might
+        * point to free()d memory, if it still matches, the rcu_read_lock()
+        * ensures the memory stays valid.
+        */
+       barrier();
+
+       return owner->on_cpu;
+}
+
+/*
+ * Look out! "owner" is an entirely speculative pointer
+ * access and not reliable.
+ */
+int mutex_spin_on_owner(struct mutex *lock, struct task_struct *owner)
+{
+       if (!sched_feat(OWNER_SPIN))
+               return 0;
+
+       rcu_read_lock();
+       while (owner_running(lock, owner)) {
+               if (need_resched())
+                       break;
+
+               arch_mutex_cpu_relax();
+       }
+       rcu_read_unlock();
+
+       /*
+        * We break out the loop above on need_resched() and when the
+        * owner changed, which is a sign for heavy contention. Return
+        * success only when lock->owner is NULL.
+        */
+       return lock->owner == NULL;
+}
+#endif
+
+#ifdef CONFIG_PREEMPT
+/*
+ * this is the entry point to schedule() from in-kernel preemption
+ * off of preempt_enable. Kernel preemptions off return from interrupt
+ * occur there and call schedule directly.
+ */
+asmlinkage void __sched notrace preempt_schedule(void)
+{
+       struct thread_info *ti = current_thread_info();
+
+       /*
+        * If there is a non-zero preempt_count or interrupts are disabled,
+        * we do not want to preempt the current task. Just return..
+        */
+       if (likely(ti->preempt_count || irqs_disabled()))
+               return;
+
+       do {
+               add_preempt_count_notrace(PREEMPT_ACTIVE);
+               __schedule();
+               sub_preempt_count_notrace(PREEMPT_ACTIVE);
+
+               /*
+                * Check again in case we missed a preemption opportunity
+                * between schedule and now.
+                */
+               barrier();
+       } while (need_resched());
+}
+EXPORT_SYMBOL(preempt_schedule);
+
+/*
+ * this is the entry point to schedule() from kernel preemption
+ * off of irq context.
+ * Note, that this is called and return with irqs disabled. This will
+ * protect us against recursive calling from irq.
+ */
+asmlinkage void __sched preempt_schedule_irq(void)
+{
+       struct thread_info *ti = current_thread_info();
+
+       /* Catch callers which need to be fixed */
+       BUG_ON(ti->preempt_count || !irqs_disabled());
+
+       user_exit();
+       do {
+               add_preempt_count(PREEMPT_ACTIVE);
+               local_irq_enable();
+               __schedule();
+               local_irq_disable();
+               sub_preempt_count(PREEMPT_ACTIVE);
+
+               /*
+                * Check again in case we missed a preemption opportunity
+                * between schedule and now.
+                */
+               barrier();
+       } while (need_resched());
+}
+
+#endif /* CONFIG_PREEMPT */
+
+int default_wake_function(wait_queue_t *curr, unsigned mode, int wake_flags,
+                         void *key)
+{
+       return try_to_wake_up(curr->private, mode, wake_flags);
+}
+EXPORT_SYMBOL(default_wake_function);
+
+/*
+ * The core wakeup function. Non-exclusive wakeups (nr_exclusive == 0) just
+ * wake everything up. If it's an exclusive wakeup (nr_exclusive == small +ve
+ * number) then we wake all the non-exclusive tasks and one exclusive task.
+ *
+ * There are circumstances in which we can try to wake a task which has already
+ * started to run but is not in state TASK_RUNNING. try_to_wake_up() returns
+ * zero in this (rare) case, and we handle it by continuing to scan the queue.
+ */
+static void __wake_up_common(wait_queue_head_t *q, unsigned int mode,
+                       int nr_exclusive, int wake_flags, void *key)
+{
+       wait_queue_t *curr, *next;
+
+       list_for_each_entry_safe(curr, next, &q->task_list, task_list) {
+               unsigned flags = curr->flags;
+
+               if (curr->func(curr, mode, wake_flags, key) &&
+                               (flags & WQ_FLAG_EXCLUSIVE) && !--nr_exclusive)
+                       break;
+       }
+}
+
+/**
+ * __wake_up - wake up threads blocked on a waitqueue.
+ * @q: the waitqueue
+ * @mode: which threads
+ * @nr_exclusive: how many wake-one or wake-many threads to wake up
+ * @key: is directly passed to the wakeup function
+ *
+ * It may be assumed that this function implies a write memory barrier before
+ * changing the task state if and only if any tasks are woken up.
+ */
+void __wake_up(wait_queue_head_t *q, unsigned int mode,
+                       int nr_exclusive, void *key)
+{
+       unsigned long flags;
+
+       spin_lock_irqsave(&q->lock, flags);
+       __wake_up_common(q, mode, nr_exclusive, 0, key);
+       spin_unlock_irqrestore(&q->lock, flags);
+}
+EXPORT_SYMBOL(__wake_up);
+
+/*
+ * Same as __wake_up but called with the spinlock in wait_queue_head_t held.
+ */
+void __wake_up_locked(wait_queue_head_t *q, unsigned int mode, int nr)
+{
+       __wake_up_common(q, mode, nr, 0, NULL);
+}
+EXPORT_SYMBOL_GPL(__wake_up_locked);
+
+void __wake_up_locked_key(wait_queue_head_t *q, unsigned int mode, void *key)
+{
+       __wake_up_common(q, mode, 1, 0, key);
+}
+EXPORT_SYMBOL_GPL(__wake_up_locked_key);
+
+/**
+ * __wake_up_sync_key - wake up threads blocked on a waitqueue.
+ * @q: the waitqueue
+ * @mode: which threads
+ * @nr_exclusive: how many wake-one or wake-many threads to wake up
+ * @key: opaque value to be passed to wakeup targets
+ *
+ * The sync wakeup differs that the waker knows that it will schedule
+ * away soon, so while the target thread will be woken up, it will not
+ * be migrated to another CPU - ie. the two threads are 'synchronized'
+ * with each other. This can prevent needless bouncing between CPUs.
+ *
+ * On UP it can prevent extra preemption.
+ *
+ * It may be assumed that this function implies a write memory barrier before
+ * changing the task state if and only if any tasks are woken up.
+ */
+void __wake_up_sync_key(wait_queue_head_t *q, unsigned int mode,
+                       int nr_exclusive, void *key)
+{
+       unsigned long flags;
+       int wake_flags = WF_SYNC;
+
+       if (unlikely(!q))
+               return;
+
+       if (unlikely(!nr_exclusive))
+               wake_flags = 0;
+
+       spin_lock_irqsave(&q->lock, flags);
+       __wake_up_common(q, mode, nr_exclusive, wake_flags, key);
+       spin_unlock_irqrestore(&q->lock, flags);
+}
+EXPORT_SYMBOL_GPL(__wake_up_sync_key);
+
+/*
+ * __wake_up_sync - see __wake_up_sync_key()
+ */
+void __wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr_exclusive)
+{
+       __wake_up_sync_key(q, mode, nr_exclusive, NULL);
+}
+EXPORT_SYMBOL_GPL(__wake_up_sync);     /* For internal use only */
+
+/**
+ * complete: - signals a single thread waiting on this completion
+ * @x:  holds the state of this particular completion
+ *
+ * This will wake up a single thread waiting on this completion. Threads will be
+ * awakened in the same order in which they were queued.
+ *
+ * See also complete_all(), wait_for_completion() and related routines.
+ *
+ * It may be assumed that this function implies a write memory barrier before
+ * changing the task state if and only if any tasks are woken up.
+ */
+void complete(struct completion *x)
+{
+       unsigned long flags;
+
+       spin_lock_irqsave(&x->wait.lock, flags);
+       x->done++;
+       __wake_up_common(&x->wait, TASK_NORMAL, 1, 0, NULL);
+       spin_unlock_irqrestore(&x->wait.lock, flags);
+}
+EXPORT_SYMBOL(complete);
+
+/**
+ * complete_all: - signals all threads waiting on this completion
+ * @x:  holds the state of this particular completion
+ *
+ * This will wake up all threads waiting on this particular completion event.
+ *
+ * It may be assumed that this function implies a write memory barrier before
+ * changing the task state if and only if any tasks are woken up.
+ */
+void complete_all(struct completion *x)
+{
+       unsigned long flags;
+
+       spin_lock_irqsave(&x->wait.lock, flags);
+       x->done += UINT_MAX/2;
+       __wake_up_common(&x->wait, TASK_NORMAL, 0, 0, NULL);
+       spin_unlock_irqrestore(&x->wait.lock, flags);
+}
+EXPORT_SYMBOL(complete_all);
+
+static inline long __sched
+do_wait_for_common(struct completion *x,
+                  long (*action)(long), long timeout, int state)
+{
+       if (!x->done) {
+               DECLARE_WAITQUEUE(wait, current);
+
+               __add_wait_queue_tail_exclusive(&x->wait, &wait);
+               do {
+                       if (signal_pending_state(state, current)) {
+                               timeout = -ERESTARTSYS;
+                               break;
+                       }
+                       __set_current_state(state);
+                       spin_unlock_irq(&x->wait.lock);
+                       timeout = action(timeout);
+                       spin_lock_irq(&x->wait.lock);
+               } while (!x->done && timeout);
+               __remove_wait_queue(&x->wait, &wait);
+               if (!x->done)
+                       return timeout;
+       }
+       x->done--;
+       return timeout ?: 1;
+}
+
+static inline long __sched
+__wait_for_common(struct completion *x,
+                 long (*action)(long), long timeout, int state)
+{
+       might_sleep();
+
+       spin_lock_irq(&x->wait.lock);
+       timeout = do_wait_for_common(x, action, timeout, state);
+       spin_unlock_irq(&x->wait.lock);
+       return timeout;
+}
+
+static long __sched
+wait_for_common(struct completion *x, long timeout, int state)
+{
+       return __wait_for_common(x, schedule_timeout, timeout, state);
+}
+
+static long __sched
+wait_for_common_io(struct completion *x, long timeout, int state)
+{
+       return __wait_for_common(x, io_schedule_timeout, timeout, state);
+}
+
+/**
+ * wait_for_completion: - waits for completion of a task
+ * @x:  holds the state of this particular completion
+ *
+ * This waits to be signaled for completion of a specific task. It is NOT
+ * interruptible and there is no timeout.
+ *
+ * See also similar routines (i.e. wait_for_completion_timeout()) with timeout
+ * and interrupt capability. Also see complete().
+ */
+void __sched wait_for_completion(struct completion *x)
+{
+       wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_UNINTERRUPTIBLE);
+}
+EXPORT_SYMBOL(wait_for_completion);
+
+/**
+ * wait_for_completion_timeout: - waits for completion of a task (w/timeout)
+ * @x:  holds the state of this particular completion
+ * @timeout:  timeout value in jiffies
+ *
+ * This waits for either a completion of a specific task to be signaled or for a
+ * specified timeout to expire. The timeout is in jiffies. It is not
+ * interruptible.
+ *
+ * The return value is 0 if timed out, and positive (at least 1, or number of
+ * jiffies left till timeout) if completed.
+ */
+unsigned long __sched
+wait_for_completion_timeout(struct completion *x, unsigned long timeout)
+{
+       return wait_for_common(x, timeout, TASK_UNINTERRUPTIBLE);
+}
+EXPORT_SYMBOL(wait_for_completion_timeout);
+
+/**
+ * wait_for_completion_io: - waits for completion of a task
+ * @x:  holds the state of this particular completion
+ *
+ * This waits to be signaled for completion of a specific task. It is NOT
+ * interruptible and there is no timeout. The caller is accounted as waiting
+ * for IO.
+ */
+void __sched wait_for_completion_io(struct completion *x)
+{
+       wait_for_common_io(x, MAX_SCHEDULE_TIMEOUT, TASK_UNINTERRUPTIBLE);
+}
+EXPORT_SYMBOL(wait_for_completion_io);
+
+/**
+ * wait_for_completion_io_timeout: - waits for completion of a task (w/timeout)
+ * @x:  holds the state of this particular completion
+ * @timeout:  timeout value in jiffies
+ *
+ * This waits for either a completion of a specific task to be signaled or for a
+ * specified timeout to expire. The timeout is in jiffies. It is not
+ * interruptible. The caller is accounted as waiting for IO.
+ *
+ * The return value is 0 if timed out, and positive (at least 1, or number of
+ * jiffies left till timeout) if completed.
+ */
+unsigned long __sched
+wait_for_completion_io_timeout(struct completion *x, unsigned long timeout)
+{
+       return wait_for_common_io(x, timeout, TASK_UNINTERRUPTIBLE);
+}
+EXPORT_SYMBOL(wait_for_completion_io_timeout);
+
+/**
+ * wait_for_completion_interruptible: - waits for completion of a task (w/intr)
+ * @x:  holds the state of this particular completion
+ *
+ * This waits for completion of a specific task to be signaled. It is
+ * interruptible.
+ *
+ * The return value is -ERESTARTSYS if interrupted, 0 if completed.
+ */
+int __sched wait_for_completion_interruptible(struct completion *x)
+{
+       long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_INTERRUPTIBLE);
+       if (t == -ERESTARTSYS)
+               return t;
+       return 0;
+}
+EXPORT_SYMBOL(wait_for_completion_interruptible);
+
+/**
+ * wait_for_completion_interruptible_timeout: - waits for completion (w/(to,intr))
+ * @x:  holds the state of this particular completion
+ * @timeout:  timeout value in jiffies
+ *
+ * This waits for either a completion of a specific task to be signaled or for a
+ * specified timeout to expire. It is interruptible. The timeout is in jiffies.
+ *
+ * The return value is -ERESTARTSYS if interrupted, 0 if timed out,
+ * positive (at least 1, or number of jiffies left till timeout) if completed.
+ */
+long __sched
+wait_for_completion_interruptible_timeout(struct completion *x,
+                                         unsigned long timeout)
+{
+       return wait_for_common(x, timeout, TASK_INTERRUPTIBLE);
+}
+EXPORT_SYMBOL(wait_for_completion_interruptible_timeout);
+
+/**
+ * wait_for_completion_killable: - waits for completion of a task (killable)
+ * @x:  holds the state of this particular completion
+ *
+ * This waits to be signaled for completion of a specific task. It can be
+ * interrupted by a kill signal.
+ *
+ * The return value is -ERESTARTSYS if interrupted, 0 if completed.
+ */
+int __sched wait_for_completion_killable(struct completion *x)
+{
+       long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_KILLABLE);
+       if (t == -ERESTARTSYS)
+               return t;
+       return 0;
+}
+EXPORT_SYMBOL(wait_for_completion_killable);
+
+/**
+ * wait_for_completion_killable_timeout: - waits for completion of a task (w/(to,killable))
+ * @x:  holds the state of this particular completion
+ * @timeout:  timeout value in jiffies
+ *
+ * This waits for either a completion of a specific task to be
+ * signaled or for a specified timeout to expire. It can be
+ * interrupted by a kill signal. The timeout is in jiffies.
+ *
+ * The return value is -ERESTARTSYS if interrupted, 0 if timed out,
+ * positive (at least 1, or number of jiffies left till timeout) if completed.
+ */
+long __sched
+wait_for_completion_killable_timeout(struct completion *x,
+                                    unsigned long timeout)
+{
+       return wait_for_common(x, timeout, TASK_KILLABLE);
+}
+EXPORT_SYMBOL(wait_for_completion_killable_timeout);
+
+/**
+ *     try_wait_for_completion - try to decrement a completion without blocking
+ *     @x:     completion structure
+ *
+ *     Returns: 0 if a decrement cannot be done without blocking
+ *              1 if a decrement succeeded.
+ *
+ *     If a completion is being used as a counting completion,
+ *     attempt to decrement the counter without blocking. This
+ *     enables us to avoid waiting if the resource the completion
+ *     is protecting is not available.
+ */
+bool try_wait_for_completion(struct completion *x)
+{
+       unsigned long flags;
+       int ret = 1;
+
+       spin_lock_irqsave(&x->wait.lock, flags);
+       if (!x->done)
+               ret = 0;
+       else
+               x->done--;
+       spin_unlock_irqrestore(&x->wait.lock, flags);
+       return ret;
+}
+EXPORT_SYMBOL(try_wait_for_completion);
+
+/**
+ *     completion_done - Test to see if a completion has any waiters
+ *     @x:     completion structure
+ *
+ *     Returns: 0 if there are waiters (wait_for_completion() in progress)
+ *              1 if there are no waiters.
+ *
+ */
+bool completion_done(struct completion *x)
+{
+       unsigned long flags;
+       int ret = 1;
+
+       spin_lock_irqsave(&x->wait.lock, flags);
+       if (!x->done)
+               ret = 0;
+       spin_unlock_irqrestore(&x->wait.lock, flags);
+       return ret;
+}
+EXPORT_SYMBOL(completion_done);
+
+static long __sched
+sleep_on_common(wait_queue_head_t *q, int state, long timeout)
+{
+       unsigned long flags;
+       wait_queue_t wait;
+
+       init_waitqueue_entry(&wait, current);
+
+       __set_current_state(state);
+
+       spin_lock_irqsave(&q->lock, flags);
+       __add_wait_queue(q, &wait);
+       spin_unlock(&q->lock);
+       timeout = schedule_timeout(timeout);
+       spin_lock_irq(&q->lock);
+       __remove_wait_queue(q, &wait);
+       spin_unlock_irqrestore(&q->lock, flags);
+
+       return timeout;
+}
+
+void __sched interruptible_sleep_on(wait_queue_head_t *q)
+{
+       sleep_on_common(q, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
+}
+EXPORT_SYMBOL(interruptible_sleep_on);
+
+long __sched
+interruptible_sleep_on_timeout(wait_queue_head_t *q, long timeout)
+{
+       return sleep_on_common(q, TASK_INTERRUPTIBLE, timeout);
+}
+EXPORT_SYMBOL(interruptible_sleep_on_timeout);
+
+void __sched sleep_on(wait_queue_head_t *q)
+{
+       sleep_on_common(q, TASK_UNINTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
+}
+EXPORT_SYMBOL(sleep_on);
+
+long __sched sleep_on_timeout(wait_queue_head_t *q, long timeout)
+{
+       return sleep_on_common(q, TASK_UNINTERRUPTIBLE, timeout);
+}
+EXPORT_SYMBOL(sleep_on_timeout);
+
+#ifdef CONFIG_RT_MUTEXES
+
+/*
+ * rt_mutex_setprio - set the current priority of a task
+ * @p: task
+ * @prio: prio value (kernel-internal form)
+ *
+ * This function changes the 'effective' priority of a task. It does
+ * not touch ->normal_prio like __setscheduler().
+ *
+ * Used by the rt_mutex code to implement priority inheritance logic.
+ */
+void rt_mutex_setprio(struct task_struct *p, int prio)
+{
+       int oldprio, on_rq, running;
+       struct rq *rq;
+       const struct sched_class *prev_class;
+
+       BUG_ON(prio < 0 || prio > MAX_PRIO);
+
+       rq = __task_rq_lock(p);
+
+       /*
+        * Idle task boosting is a nono in general. There is one
+        * exception, when PREEMPT_RT and NOHZ is active:
+        *
+        * The idle task calls get_next_timer_interrupt() and holds
+        * the timer wheel base->lock on the CPU and another CPU wants
+        * to access the timer (probably to cancel it). We can safely
+        * ignore the boosting request, as the idle CPU runs this code
+        * with interrupts disabled and will complete the lock
+        * protected section without being interrupted. So there is no
+        * real need to boost.
+        */
+       if (unlikely(p == rq->idle)) {
+               WARN_ON(p != rq->curr);
+               WARN_ON(p->pi_blocked_on);
+               goto out_unlock;
+       }
+
+       trace_sched_pi_setprio(p, prio);
+       oldprio = p->prio;
+       prev_class = p->sched_class;
+       on_rq = p->on_rq;
+       running = task_current(rq, p);
+       if (on_rq)
+               dequeue_task(rq, p, 0);
+       if (running)
+               p->sched_class->put_prev_task(rq, p);
+
+       if (rt_prio(prio))
+               p->sched_class = &rt_sched_class;
+       else
+               p->sched_class = &fair_sched_class;
+
+       p->prio = prio;
+
+       if (running)
+               p->sched_class->set_curr_task(rq);
+       if (on_rq)
+               enqueue_task(rq, p, oldprio < prio ? ENQUEUE_HEAD : 0);
+
+       check_class_changed(rq, p, prev_class, oldprio);
+out_unlock:
+       __task_rq_unlock(rq);
+}
+#endif
+void set_user_nice(struct task_struct *p, long nice)
+{
+       int old_prio, delta, on_rq;
+       unsigned long flags;
+       struct rq *rq;
+
+       if (TASK_NICE(p) == nice || nice < -20 || nice > 19)
+               return;
+       /*
+        * We have to be careful, if called from sys_setpriority(),
+        * the task might be in the middle of scheduling on another CPU.
+        */
+       rq = task_rq_lock(p, &flags);
+       /*
+        * The RT priorities are set via sched_setscheduler(), but we still
+        * allow the 'normal' nice value to be set - but as expected
+        * it wont have any effect on scheduling until the task is
+        * SCHED_FIFO/SCHED_RR:
+        */
+       if (task_has_rt_policy(p)) {
+               p->static_prio = NICE_TO_PRIO(nice);
+               goto out_unlock;
+       }
+       on_rq = p->on_rq;
+       if (on_rq)
+               dequeue_task(rq, p, 0);
+
+       p->static_prio = NICE_TO_PRIO(nice);
+       set_load_weight(p);
+       old_prio = p->prio;
+       p->prio = effective_prio(p);
+       delta = p->prio - old_prio;
+
+       if (on_rq) {
+               enqueue_task(rq, p, 0);
+               /*
+                * If the task increased its priority or is running and
+                * lowered its priority, then reschedule its CPU:
+                */
+               if (delta < 0 || (delta > 0 && task_running(rq, p)))
+                       resched_task(rq->curr);
+       }
+out_unlock:
+       task_rq_unlock(rq, p, &flags);
+}
+EXPORT_SYMBOL(set_user_nice);
+
+/*
+ * can_nice - check if a task can reduce its nice value
+ * @p: task
+ * @nice: nice value
+ */
+int can_nice(const struct task_struct *p, const int nice)
+{
+       /* convert nice value [19,-20] to rlimit style value [1,40] */
+       int nice_rlim = 20 - nice;
+
+       return (nice_rlim <= task_rlimit(p, RLIMIT_NICE) ||
+               capable(CAP_SYS_NICE));
+}
+
+#ifdef __ARCH_WANT_SYS_NICE
+
+/*
+ * sys_nice - change the priority of the current process.
+ * @increment: priority increment
+ *
+ * sys_setpriority is a more generic, but much slower function that
+ * does similar things.
+ */
+SYSCALL_DEFINE1(nice, int, increment)
+{
+       long nice, retval;
+
+       /*
+        * Setpriority might change our priority at the same moment.
+        * We don't have to worry. Conceptually one call occurs first
+        * and we have a single winner.
+        */
+       if (increment < -40)
+               increment = -40;
+       if (increment > 40)
+               increment = 40;
+
+       nice = TASK_NICE(current) + increment;
+       if (nice < -20)
+               nice = -20;
+       if (nice > 19)
+               nice = 19;
+
+       if (increment < 0 && !can_nice(current, nice))
+               return -EPERM;
+
+       retval = security_task_setnice(current, nice);
+       if (retval)
+               return retval;
+
+       set_user_nice(current, nice);
+       return 0;
+}
+
+#endif
+
+/**
+ * task_prio - return the priority value of a given task.
+ * @p: the task in question.
+ *
+ * This is the priority value as seen by users in /proc.
+ * RT tasks are offset by -200. Normal tasks are centered
+ * around 0, value goes from -16 to +15.
+ */
+int task_prio(const struct task_struct *p)
+{
+       return p->prio - MAX_RT_PRIO;
+}
+
+/**
+ * task_nice - return the nice value of a given task.
+ * @p: the task in question.
+ */
+int task_nice(const struct task_struct *p)
+{
+       return TASK_NICE(p);
+}
+EXPORT_SYMBOL(task_nice);
+
+/**
+ * idle_cpu - is a given cpu idle currently?
+ * @cpu: the processor in question.
+ */
+int idle_cpu(int cpu)
+{
+       struct rq *rq = cpu_rq(cpu);
+
+       if (rq->curr != rq->idle)
+               return 0;
+
+       if (rq->nr_running)
+               return 0;
+
+#ifdef CONFIG_SMP
+       if (!llist_empty(&rq->wake_list))
+               return 0;
+#endif
+
+       return 1;
+}
+
+/**
+ * idle_task - return the idle task for a given cpu.
+ * @cpu: the processor in question.
+ */
+struct task_struct *idle_task(int cpu)
+{
+       return cpu_rq(cpu)->idle;
+}
+
+/**
+ * find_process_by_pid - find a process with a matching PID value.
+ * @pid: the pid in question.
+ */
+static struct task_struct *find_process_by_pid(pid_t pid)
+{
+       return pid ? find_task_by_vpid(pid) : current;
+}
+
+/* Actually do priority change: must hold rq lock. */
+static void
+__setscheduler(struct rq *rq, struct task_struct *p, int policy, int prio)
+{
+       p->policy = policy;
+       p->rt_priority = prio;
+       p->normal_prio = normal_prio(p);
+       /* we are holding p->pi_lock already */
+       p->prio = rt_mutex_getprio(p);
+       if (rt_prio(p->prio))
+               p->sched_class = &rt_sched_class;
+       else
+               p->sched_class = &fair_sched_class;
+       set_load_weight(p);
+}
+
+/*
+ * check the target process has a UID that matches the current process's
+ */
+static bool check_same_owner(struct task_struct *p)
+{
+       const struct cred *cred = current_cred(), *pcred;
+       bool match;
+
+       rcu_read_lock();
+       pcred = __task_cred(p);
+       match = (uid_eq(cred->euid, pcred->euid) ||
+                uid_eq(cred->euid, pcred->uid));
+       rcu_read_unlock();
+       return match;
+}
+
+static int __sched_setscheduler(struct task_struct *p, int policy,
+                               const struct sched_param *param, bool user)
+{
+       int retval, oldprio, oldpolicy = -1, on_rq, running;
+       unsigned long flags;
+       const struct sched_class *prev_class;
+       struct rq *rq;
+       int reset_on_fork;
+
+       /* may grab non-irq protected spin_locks */
+       BUG_ON(in_interrupt());
+recheck:
+       /* double check policy once rq lock held */
+       if (policy < 0) {
+               reset_on_fork = p->sched_reset_on_fork;
+               policy = oldpolicy = p->policy;
+       } else {
+               reset_on_fork = !!(policy & SCHED_RESET_ON_FORK);
+               policy &= ~SCHED_RESET_ON_FORK;
+
+               if (policy != SCHED_FIFO && policy != SCHED_RR &&
+                               policy != SCHED_NORMAL && policy != SCHED_BATCH &&
+                               policy != SCHED_IDLE)
+                       return -EINVAL;
+       }
+
+       /*
+        * Valid priorities for SCHED_FIFO and SCHED_RR are
+        * 1..MAX_USER_RT_PRIO-1, valid priority for SCHED_NORMAL,
+        * SCHED_BATCH and SCHED_IDLE is 0.
+        */
+       if (param->sched_priority < 0 ||
+           (p->mm && param->sched_priority > MAX_USER_RT_PRIO-1) ||
+           (!p->mm && param->sched_priority > MAX_RT_PRIO-1))
+               return -EINVAL;
+       if (rt_policy(policy) != (param->sched_priority != 0))
+               return -EINVAL;
+
+       /*
+        * Allow unprivileged RT tasks to decrease priority:
+        */
+       if (user && !capable(CAP_SYS_NICE)) {
+               if (rt_policy(policy)) {
+                       unsigned long rlim_rtprio =
+                                       task_rlimit(p, RLIMIT_RTPRIO);
+
+                       /* can't set/change the rt policy */
+                       if (policy != p->policy && !rlim_rtprio)
+                               return -EPERM;
+
+                       /* can't increase priority */
+                       if (param->sched_priority > p->rt_priority &&
+                           param->sched_priority > rlim_rtprio)
+                               return -EPERM;
+               }
+
+               /*
+                * Treat SCHED_IDLE as nice 20. Only allow a switch to
+                * SCHED_NORMAL if the RLIMIT_NICE would normally permit it.
+                */
+               if (p->policy == SCHED_IDLE && policy != SCHED_IDLE) {
+                       if (!can_nice(p, TASK_NICE(p)))
+                               return -EPERM;
+               }
+
+               /* can't change other user's priorities */
+               if (!check_same_owner(p))
+                       return -EPERM;
+
+               /* Normal users shall not reset the sched_reset_on_fork flag */
+               if (p->sched_reset_on_fork && !reset_on_fork)
+                       return -EPERM;
+       }
+
+       if (user) {
+               retval = security_task_setscheduler(p);
+               if (retval)
+                       return retval;
+       }
+
+       /*
+        * make sure no PI-waiters arrive (or leave) while we are
+        * changing the priority of the task:
+        *
+        * To be able to change p->policy safely, the appropriate
+        * runqueue lock must be held.
+        */
+       rq = task_rq_lock(p, &flags);
+
+       /*
+        * Changing the policy of the stop threads its a very bad idea
+        */
+       if (p == rq->stop) {
+               task_rq_unlock(rq, p, &flags);
+               return -EINVAL;
+       }
+
+       /*
+        * If not changing anything there's no need to proceed further:
+        */
+       if (unlikely(policy == p->policy && (!rt_policy(policy) ||
+                       param->sched_priority == p->rt_priority))) {
+               task_rq_unlock(rq, p, &flags);
+               return 0;
+       }
+
+#ifdef CONFIG_RT_GROUP_SCHED
+       if (user) {
+               /*
+                * Do not allow realtime tasks into groups that have no runtime
+                * assigned.
+                */
+               if (rt_bandwidth_enabled() && rt_policy(policy) &&
+                               task_group(p)->rt_bandwidth.rt_runtime == 0 &&
+                               !task_group_is_autogroup(task_group(p))) {
+                       task_rq_unlock(rq, p, &flags);
+                       return -EPERM;
+               }
+       }
+#endif
+
+       /* recheck policy now with rq lock held */
+       if (unlikely(oldpolicy != -1 && oldpolicy != p->policy)) {
+               policy = oldpolicy = -1;
+               task_rq_unlock(rq, p, &flags);
+               goto recheck;
+       }
+       on_rq = p->on_rq;
+       running = task_current(rq, p);
+       if (on_rq)
+               dequeue_task(rq, p, 0);
+       if (running)
+               p->sched_class->put_prev_task(rq, p);
+
+       p->sched_reset_on_fork = reset_on_fork;
+
+       oldprio = p->prio;
+       prev_class = p->sched_class;
+       __setscheduler(rq, p, policy, param->sched_priority);
+
+       if (running)
+               p->sched_class->set_curr_task(rq);
+       if (on_rq)
+               enqueue_task(rq, p, 0);
+
+       check_class_changed(rq, p, prev_class, oldprio);
+       task_rq_unlock(rq, p, &flags);
+
+       rt_mutex_adjust_pi(p);
+
+       return 0;
+}
+
+/**
+ * sched_setscheduler - change the scheduling policy and/or RT priority of a thread.
+ * @p: the task in question.
+ * @policy: new policy.
+ * @param: structure containing the new RT priority.
+ *
+ * NOTE that the task may be already dead.
+ */
+int sched_setscheduler(struct task_struct *p, int policy,
+                      const struct sched_param *param)
+{
+       return __sched_setscheduler(p, policy, param, true);
+}
+EXPORT_SYMBOL_GPL(sched_setscheduler);
+
+/**
+ * sched_setscheduler_nocheck - change the scheduling policy and/or RT priority of a thread from kernelspace.
+ * @p: the task in question.
+ * @policy: new policy.
+ * @param: structure containing the new RT priority.
+ *
+ * Just like sched_setscheduler, only don't bother checking if the
+ * current context has permission.  For example, this is needed in
+ * stop_machine(): we create temporary high priority worker threads,
+ * but our caller might not have that capability.
+ */
+int sched_setscheduler_nocheck(struct task_struct *p, int policy,
+                              const struct sched_param *param)
+{
+       return __sched_setscheduler(p, policy, param, false);
+}
+
+static int
+do_sched_setscheduler(pid_t pid, int policy, struct sched_param __user *param)
+{
+       struct sched_param lparam;
+       struct task_struct *p;
+       int retval;
+
+       if (!param || pid < 0)
+               return -EINVAL;
+       if (copy_from_user(&lparam, param, sizeof(struct sched_param)))
+               return -EFAULT;
+
+       rcu_read_lock();
+       retval = -ESRCH;
+       p = find_process_by_pid(pid);
+       if (p != NULL)
+               retval = sched_setscheduler(p, policy, &lparam);
+       rcu_read_unlock();
+
+       return retval;
+}
+
+/**
+ * sys_sched_setscheduler - set/change the scheduler policy and RT priority
+ * @pid: the pid in question.
+ * @policy: new policy.
+ * @param: structure containing the new RT priority.
+ */
+SYSCALL_DEFINE3(sched_setscheduler, pid_t, pid, int, policy,
+               struct sched_param __user *, param)
+{
+       /* negative values for policy are not valid */
+       if (policy < 0)
+               return -EINVAL;
+
+       return do_sched_setscheduler(pid, policy, param);
+}
+
+/**
+ * sys_sched_setparam - set/change the RT priority of a thread
+ * @pid: the pid in question.
+ * @param: structure containing the new RT priority.
+ */
+SYSCALL_DEFINE2(sched_setparam, pid_t, pid, struct sched_param __user *, param)
+{
+       return do_sched_setscheduler(pid, -1, param);
+}
+
+/**
+ * sys_sched_getscheduler - get the policy (scheduling class) of a thread
+ * @pid: the pid in question.
+ */
+SYSCALL_DEFINE1(sched_getscheduler, pid_t, pid)
+{
+       struct task_struct *p;
+       int retval;
+
+       if (pid < 0)
+               return -EINVAL;
+
+       retval = -ESRCH;
+       rcu_read_lock();
+       p = find_process_by_pid(pid);
+       if (p) {
+               retval = security_task_getscheduler(p);
+               if (!retval)
+                       retval = p->policy
+                               | (p->sched_reset_on_fork ? SCHED_RESET_ON_FORK : 0);
+       }
+       rcu_read_unlock();
+       return retval;
+}
+
+/**
+ * sys_sched_getparam - get the RT priority of a thread
+ * @pid: the pid in question.
+ * @param: structure containing the RT priority.
+ */
+SYSCALL_DEFINE2(sched_getparam, pid_t, pid, struct sched_param __user *, param)
+{
+       struct sched_param lp;
+       struct task_struct *p;
+       int retval;
+
+       if (!param || pid < 0)
+               return -EINVAL;
+
+       rcu_read_lock();
+       p = find_process_by_pid(pid);
+       retval = -ESRCH;
+       if (!p)
+               goto out_unlock;
+
+       retval = security_task_getscheduler(p);
+       if (retval)
+               goto out_unlock;
+
+       lp.sched_priority = p->rt_priority;
+       rcu_read_unlock();
+
+       /*
+        * This one might sleep, we cannot do it with a spinlock held ...
+        */
+       retval = copy_to_user(param, &lp, sizeof(*param)) ? -EFAULT : 0;
+
+       return retval;
+
+out_unlock:
+       rcu_read_unlock();
+       return retval;
+}
+
+long sched_setaffinity(pid_t pid, const struct cpumask *in_mask)
+{
+       cpumask_var_t cpus_allowed, new_mask;
+       struct task_struct *p;
+       int retval;
+
+       get_online_cpus();
+       rcu_read_lock();
+
+       p = find_process_by_pid(pid);
+       if (!p) {
+               rcu_read_unlock();
+               put_online_cpus();
+               return -ESRCH;
+       }
+
+       /* Prevent p going away */
+       get_task_struct(p);
+       rcu_read_unlock();
+
+       if (!alloc_cpumask_var(&cpus_allowed, GFP_KERNEL)) {
+               retval = -ENOMEM;
+               goto out_put_task;
+       }
+       if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) {
+               retval = -ENOMEM;
+               goto out_free_cpus_allowed;
+       }
+       retval = -EPERM;
+       if (!check_same_owner(p)) {
+               rcu_read_lock();
+               if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) {
+                       rcu_read_unlock();
+                       goto out_unlock;
+               }
+               rcu_read_unlock();
+       }
+
+       retval = security_task_setscheduler(p);
+       if (retval)
+               goto out_unlock;
+
+       cpuset_cpus_allowed(p, cpus_allowed);
+       cpumask_and(new_mask, in_mask, cpus_allowed);
+again:
+       retval = set_cpus_allowed_ptr(p, new_mask);
+
+       if (!retval) {
+               cpuset_cpus_allowed(p, cpus_allowed);
+               if (!cpumask_subset(new_mask, cpus_allowed)) {
+                       /*
+                        * We must have raced with a concurrent cpuset
+                        * update. Just reset the cpus_allowed to the
+                        * cpuset's cpus_allowed
+                        */
+                       cpumask_copy(new_mask, cpus_allowed);
+                       goto again;
+               }
+       }
+out_unlock:
+       free_cpumask_var(new_mask);
+out_free_cpus_allowed:
+       free_cpumask_var(cpus_allowed);
+out_put_task:
+       put_task_struct(p);
+       put_online_cpus();
+       return retval;
+}
+
+static int get_user_cpu_mask(unsigned long __user *user_mask_ptr, unsigned len,
+                            struct cpumask *new_mask)
+{
+       if (len < cpumask_size())
+               cpumask_clear(new_mask);
+       else if (len > cpumask_size())
+               len = cpumask_size();
+
+       return copy_from_user(new_mask, user_mask_ptr, len) ? -EFAULT : 0;
+}
+
+/**
+ * sys_sched_setaffinity - set the cpu affinity of a process
+ * @pid: pid of the process
+ * @len: length in bytes of the bitmask pointed to by user_mask_ptr
+ * @user_mask_ptr: user-space pointer to the new cpu mask
+ */
+SYSCALL_DEFINE3(sched_setaffinity, pid_t, pid, unsigned int, len,
+               unsigned long __user *, user_mask_ptr)
+{
+       cpumask_var_t new_mask;
+       int retval;
+
+       if (!alloc_cpumask_var(&new_mask, GFP_KERNEL))
+               return -ENOMEM;
+
+       retval = get_user_cpu_mask(user_mask_ptr, len, new_mask);
+       if (retval == 0)
+               retval = sched_setaffinity(pid, new_mask);
+       free_cpumask_var(new_mask);
+       return retval;
+}
+
+long sched_getaffinity(pid_t pid, struct cpumask *mask)
+{
+       struct task_struct *p;
+       unsigned long flags;
+       int retval;
+
+       get_online_cpus();
+       rcu_read_lock();
+
+       retval = -ESRCH;
+       p = find_process_by_pid(pid);
+       if (!p)
+               goto out_unlock;
+
+       retval = security_task_getscheduler(p);
+       if (retval)
+               goto out_unlock;
+
+       raw_spin_lock_irqsave(&p->pi_lock, flags);
+       cpumask_and(mask, &p->cpus_allowed, cpu_online_mask);
+       raw_spin_unlock_irqrestore(&p->pi_lock, flags);
+
+out_unlock:
+       rcu_read_unlock();
+       put_online_cpus();
+
+       return retval;
+}
+
+/**
+ * sys_sched_getaffinity - get the cpu affinity of a process
+ * @pid: pid of the process
+ * @len: length in bytes of the bitmask pointed to by user_mask_ptr
+ * @user_mask_ptr: user-space pointer to hold the current cpu mask
+ */
+SYSCALL_DEFINE3(sched_getaffinity, pid_t, pid, unsigned int, len,
+               unsigned long __user *, user_mask_ptr)
+{
+       int ret;
+       cpumask_var_t mask;
+
+       if ((len * BITS_PER_BYTE) < nr_cpu_ids)
+               return -EINVAL;
+       if (len & (sizeof(unsigned long)-1))
+               return -EINVAL;
+
+       if (!alloc_cpumask_var(&mask, GFP_KERNEL))
+               return -ENOMEM;
+
+       ret = sched_getaffinity(pid, mask);
+       if (ret == 0) {
+               size_t retlen = min_t(size_t, len, cpumask_size());
+
+               if (copy_to_user(user_mask_ptr, mask, retlen))
+                       ret = -EFAULT;
+               else
+                       ret = retlen;
+       }
+       free_cpumask_var(mask);
+
+       return ret;
+}
+
+/**
+ * sys_sched_yield - yield the current processor to other threads.
+ *
+ * This function yields the current CPU to other tasks. If there are no
+ * other threads running on this CPU then this function will return.
+ */
+SYSCALL_DEFINE0(sched_yield)
+{
+       struct rq *rq = this_rq_lock();
+
+       schedstat_inc(rq, yld_count);
+       current->sched_class->yield_task(rq);
+
+       /*
+        * Since we are going to call schedule() anyway, there's
+        * no need to preempt or enable interrupts:
+        */
+       __release(rq->lock);
+       spin_release(&rq->lock.dep_map, 1, _THIS_IP_);
+       do_raw_spin_unlock(&rq->lock);
+       sched_preempt_enable_no_resched();
+
+       schedule();
+
+       return 0;
+}
+
+static inline int should_resched(void)
+{
+       return need_resched() && !(preempt_count() & PREEMPT_ACTIVE);
+}
+
+static void __cond_resched(void)
+{
+       add_preempt_count(PREEMPT_ACTIVE);
+       __schedule();
+       sub_preempt_count(PREEMPT_ACTIVE);
+}
+
+int __sched _cond_resched(void)
+{
+       if (should_resched()) {
+               __cond_resched();
+               return 1;
+       }
+       return 0;
+}
+EXPORT_SYMBOL(_cond_resched);
+
+/*
+ * __cond_resched_lock() - if a reschedule is pending, drop the given lock,
+ * call schedule, and on return reacquire the lock.
+ *
+ * This works OK both with and without CONFIG_PREEMPT. We do strange low-level
+ * operations here to prevent schedule() from being called twice (once via
+ * spin_unlock(), once by hand).
+ */
+int __cond_resched_lock(spinlock_t *lock)
+{
+       int resched = should_resched();
+       int ret = 0;
+
+       lockdep_assert_held(lock);
+
+       if (spin_needbreak(lock) || resched) {
+               spin_unlock(lock);
+               if (resched)
+                       __cond_resched();
+               else
+                       cpu_relax();
+               ret = 1;
+               spin_lock(lock);
+       }
+       return ret;
+}
+EXPORT_SYMBOL(__cond_resched_lock);
+
+int __sched __cond_resched_softirq(void)
+{
+       BUG_ON(!in_softirq());
+
+       if (should_resched()) {
+               local_bh_enable();
+               __cond_resched();
+               local_bh_disable();
+               return 1;
+       }
+       return 0;
+}
+EXPORT_SYMBOL(__cond_resched_softirq);
+
+/**
+ * yield - yield the current processor to other threads.
+ *
+ * Do not ever use this function, there's a 99% chance you're doing it wrong.
+ *
+ * The scheduler is at all times free to pick the calling task as the most
+ * eligible task to run, if removing the yield() call from your code breaks
+ * it, its already broken.
+ *
+ * Typical broken usage is:
+ *
+ * while (!event)
+ *     yield();
+ *
+ * where one assumes that yield() will let 'the other' process run that will
+ * make event true. If the current task is a SCHED_FIFO task that will never
+ * happen. Never use yield() as a progress guarantee!!
+ *
+ * If you want to use yield() to wait for something, use wait_event().
+ * If you want to use yield() to be 'nice' for others, use cond_resched().
+ * If you still want to use yield(), do not!
+ */
+void __sched yield(void)
+{
+       set_current_state(TASK_RUNNING);
+       sys_sched_yield();
+}
+EXPORT_SYMBOL(yield);
+
+/**
+ * yield_to - yield the current processor to another thread in
+ * your thread group, or accelerate that thread toward the
+ * processor it's on.
+ * @p: target task
+ * @preempt: whether task preemption is allowed or not
+ *
+ * It's the caller's job to ensure that the target task struct
+ * can't go away on us before we can do any checks.
+ *
+ * Returns:
+ *     true (>0) if we indeed boosted the target task.
+ *     false (0) if we failed to boost the target.
+ *     -ESRCH if there's no task to yield to.
+ */
+bool __sched yield_to(struct task_struct *p, bool preempt)
+{
+       struct task_struct *curr = current;
+       struct rq *rq, *p_rq;
+       unsigned long flags;
+       int yielded = 0;
+
+       local_irq_save(flags);
+       rq = this_rq();
+
+again:
+       p_rq = task_rq(p);
+       /*
+        * If we're the only runnable task on the rq and target rq also
+        * has only one task, there's absolutely no point in yielding.
+        */
+       if (rq->nr_running == 1 && p_rq->nr_running == 1) {
+               yielded = -ESRCH;
+               goto out_irq;
+       }
+
+       double_rq_lock(rq, p_rq);
+       while (task_rq(p) != p_rq) {
+               double_rq_unlock(rq, p_rq);
+               goto again;
+       }
+
+       if (!curr->sched_class->yield_to_task)
+               goto out_unlock;
+
+       if (curr->sched_class != p->sched_class)
+               goto out_unlock;
+
+       if (task_running(p_rq, p) || p->state)
+               goto out_unlock;
+
+       yielded = curr->sched_class->yield_to_task(rq, p, preempt);
+       if (yielded) {
+               schedstat_inc(rq, yld_count);
+               /*
+                * Make p's CPU reschedule; pick_next_entity takes care of
+                * fairness.
+                */
+               if (preempt && rq != p_rq)
+                       resched_task(p_rq->curr);
+       }
+
+out_unlock:
+       double_rq_unlock(rq, p_rq);
+out_irq:
+       local_irq_restore(flags);
+
+       if (yielded > 0)
+               schedule();
+
+       return yielded;
+}
+EXPORT_SYMBOL_GPL(yield_to);
+
+/*
+ * This task is about to go to sleep on IO. Increment rq->nr_iowait so
+ * that process accounting knows that this is a task in IO wait state.
+ */
+void __sched io_schedule(void)
+{
+       struct rq *rq = raw_rq();
+
+       delayacct_blkio_start();
+       atomic_inc(&rq->nr_iowait);
+       blk_flush_plug(current);
+       current->in_iowait = 1;
+       schedule();
+       current->in_iowait = 0;
+       atomic_dec(&rq->nr_iowait);
+       delayacct_blkio_end();
+}
+EXPORT_SYMBOL(io_schedule);
+
+long __sched io_schedule_timeout(long timeout)
+{
+       struct rq *rq = raw_rq();
+       long ret;
+
+       delayacct_blkio_start();
+       atomic_inc(&rq->nr_iowait);
+       blk_flush_plug(current);
+       current->in_iowait = 1;
+       ret = schedule_timeout(timeout);
+       current->in_iowait = 0;
+       atomic_dec(&rq->nr_iowait);
+       delayacct_blkio_end();
+       return ret;
+}
+
+/**
+ * sys_sched_get_priority_max - return maximum RT priority.
+ * @policy: scheduling class.
+ *
+ * this syscall returns the maximum rt_priority that can be used
+ * by a given scheduling class.
+ */
+SYSCALL_DEFINE1(sched_get_priority_max, int, policy)
+{
+       int ret = -EINVAL;
+
+       switch (policy) {
+       case SCHED_FIFO:
+       case SCHED_RR:
+               ret = MAX_USER_RT_PRIO-1;
+               break;
+       case SCHED_NORMAL:
+       case SCHED_BATCH:
+       case SCHED_IDLE:
+               ret = 0;
+               break;
+       }
+       return ret;
+}
+
+/**
+ * sys_sched_get_priority_min - return minimum RT priority.
+ * @policy: scheduling class.
+ *
+ * this syscall returns the minimum rt_priority that can be used
+ * by a given scheduling class.
+ */
+SYSCALL_DEFINE1(sched_get_priority_min, int, policy)
+{
+       int ret = -EINVAL;
+
+       switch (policy) {
+       case SCHED_FIFO:
+       case SCHED_RR:
+               ret = 1;
+               break;
+       case SCHED_NORMAL:
+       case SCHED_BATCH:
+       case SCHED_IDLE:
+               ret = 0;
+       }
+       return ret;
+}
+
+/**
+ * sys_sched_rr_get_interval - return the default timeslice of a process.
+ * @pid: pid of the process.
+ * @interval: userspace pointer to the timeslice value.
+ *
+ * this syscall writes the default timeslice value of a given process
+ * into the user-space timespec buffer. A value of '0' means infinity.
+ */
+SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid,
+               struct timespec __user *, interval)
+{
+       struct task_struct *p;
+       unsigned int time_slice;
+       unsigned long flags;
+       struct rq *rq;
+       int retval;
+       struct timespec t;
+
+       if (pid < 0)
+               return -EINVAL;
+
+       retval = -ESRCH;
+       rcu_read_lock();
+       p = find_process_by_pid(pid);
+       if (!p)
+               goto out_unlock;
+
+       retval = security_task_getscheduler(p);
+       if (retval)
+               goto out_unlock;
+
+       rq = task_rq_lock(p, &flags);
+       time_slice = p->sched_class->get_rr_interval(rq, p);
+       task_rq_unlock(rq, p, &flags);
+
+       rcu_read_unlock();
+       jiffies_to_timespec(time_slice, &t);
+       retval = copy_to_user(interval, &t, sizeof(t)) ? -EFAULT : 0;
+       return retval;
+
+out_unlock:
+       rcu_read_unlock();
+       return retval;
+}
+
+static const char stat_nam[] = TASK_STATE_TO_CHAR_STR;
+
+void sched_show_task(struct task_struct *p)
+{
+       unsigned long free = 0;
+       int ppid;
+       unsigned state;
+
+       state = p->state ? __ffs(p->state) + 1 : 0;
+       printk(KERN_INFO "%-15.15s %c", p->comm,
+               state < sizeof(stat_nam) - 1 ? stat_nam[state] : '?');
+#if BITS_PER_LONG == 32
+       if (state == TASK_RUNNING)
+               printk(KERN_CONT " running  ");
+       else
+               printk(KERN_CONT " %08lx ", thread_saved_pc(p));
+#else
+       if (state == TASK_RUNNING)
+               printk(KERN_CONT "  running task    ");
+       else
+               printk(KERN_CONT " %016lx ", thread_saved_pc(p));
+#endif
+#ifdef CONFIG_DEBUG_STACK_USAGE
+       free = stack_not_used(p);
+#endif
+       rcu_read_lock();
+       ppid = task_pid_nr(rcu_dereference(p->real_parent));
+       rcu_read_unlock();
+       printk(KERN_CONT "%5lu %5d %6d 0x%08lx\n", free,
+               task_pid_nr(p), ppid,
+               (unsigned long)task_thread_info(p)->flags);
+
+       show_stack(p, NULL);
+}
+
+void show_state_filter(unsigned long state_filter)
+{
+       struct task_struct *g, *p;
+
+#if BITS_PER_LONG == 32
+       printk(KERN_INFO
+               "  task                PC stack   pid father\n");
+#else
+       printk(KERN_INFO
+               "  task                        PC stack   pid father\n");
+#endif
+       rcu_read_lock();
+       do_each_thread(g, p) {
+               /*
+                * reset the NMI-timeout, listing all files on a slow
+                * console might take a lot of time:
+                */
+               touch_nmi_watchdog();
+               if (!state_filter || (p->state & state_filter))
+                       sched_show_task(p);
+       } while_each_thread(g, p);
+
+       touch_all_softlockup_watchdogs();
+
+#ifdef CONFIG_SCHED_DEBUG
+       sysrq_sched_debug_show();
+#endif
+       rcu_read_unlock();
+       /*
+        * Only show locks if all tasks are dumped:
+        */
+       if (!state_filter)
+               debug_show_all_locks();
+}
+
+void __cpuinit init_idle_bootup_task(struct task_struct *idle)
+{
+       idle->sched_class = &idle_sched_class;
+}
+
+/**
+ * init_idle - set up an idle thread for a given CPU
+ * @idle: task in question
+ * @cpu: cpu the idle task belongs to
+ *
+ * NOTE: this function does not set the idle thread's NEED_RESCHED
+ * flag, to make booting more robust.
+ */
+void __cpuinit init_idle(struct task_struct *idle, int cpu)
+{
+       struct rq *rq = cpu_rq(cpu);
+       unsigned long flags;
+
+       raw_spin_lock_irqsave(&rq->lock, flags);
+
+       __sched_fork(idle);
+       idle->state = TASK_RUNNING;
+       idle->se.exec_start = sched_clock();
+
+       do_set_cpus_allowed(idle, cpumask_of(cpu));
+       /*
+        * We're having a chicken and egg problem, even though we are
+        * holding rq->lock, the cpu isn't yet set to this cpu so the
+        * lockdep check in task_group() will fail.
+        *
+        * Similar case to sched_fork(). / Alternatively we could
+        * use task_rq_lock() here and obtain the other rq->lock.
+        *
+        * Silence PROVE_RCU
+        */
+       rcu_read_lock();
+       __set_task_cpu(idle, cpu);
+       rcu_read_unlock();
+
+       rq->curr = rq->idle = idle;
+#if defined(CONFIG_SMP)
+       idle->on_cpu = 1;
+#endif
+       raw_spin_unlock_irqrestore(&rq->lock, flags);
+
+       /* Set the preempt count _outside_ the spinlocks! */
+       task_thread_info(idle)->preempt_count = 0;
+
+       /*
+        * The idle tasks have their own, simple scheduling class:
+        */
+       idle->sched_class = &idle_sched_class;
+       ftrace_graph_init_idle_task(idle, cpu);
+       vtime_init_idle(idle);
+#if defined(CONFIG_SMP)
+       sprintf(idle->comm, "%s/%d", INIT_TASK_COMM, cpu);
+#endif
+}
+
+#ifdef CONFIG_SMP
+void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask)
+{
+       if (p->sched_class && p->sched_class->set_cpus_allowed)
+               p->sched_class->set_cpus_allowed(p, new_mask);
+
+       cpumask_copy(&p->cpus_allowed, new_mask);
+       p->nr_cpus_allowed = cpumask_weight(new_mask);
+}
+
+/*
+ * This is how migration works:
+ *
+ * 1) we invoke migration_cpu_stop() on the target CPU using
+ *    stop_one_cpu().
+ * 2) stopper starts to run (implicitly forcing the migrated thread
+ *    off the CPU)
+ * 3) it checks whether the migrated task is still in the wrong runqueue.
+ * 4) if it's in the wrong runqueue then the migration thread removes
+ *    it and puts it into the right queue.
+ * 5) stopper completes and stop_one_cpu() returns and the migration
+ *    is done.
+ */
+
+/*
+ * Change a given task's CPU affinity. Migrate the thread to a
+ * proper CPU and schedule it away if the CPU it's executing on
+ * is removed from the allowed bitmask.
+ *
+ * NOTE: the caller must have a valid reference to the task, the
+ * task must not exit() & deallocate itself prematurely. The
+ * call is not atomic; no spinlocks may be held.
+ */
+int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask)
+{
+       unsigned long flags;
+       struct rq *rq;
+       unsigned int dest_cpu;
+       int ret = 0;
+
+       rq = task_rq_lock(p, &flags);
+
+       if (cpumask_equal(&p->cpus_allowed, new_mask))
+               goto out;
+
+       if (!cpumask_intersects(new_mask, cpu_active_mask)) {
+               ret = -EINVAL;
+               goto out;
+       }
+
+       if (unlikely((p->flags & PF_THREAD_BOUND) && p != current)) {
+               ret = -EINVAL;
+               goto out;
+       }
+
+       do_set_cpus_allowed(p, new_mask);
+
+       /* Can the task run on the task's current CPU? If so, we're done */
+       if (cpumask_test_cpu(task_cpu(p), new_mask))
+               goto out;
+
+       dest_cpu = cpumask_any_and(cpu_active_mask, new_mask);
+       if (p->on_rq) {
+               struct migration_arg arg = { p, dest_cpu };
+               /* Need help from migration thread: drop lock and wait. */
+               task_rq_unlock(rq, p, &flags);
+               stop_one_cpu(cpu_of(rq), migration_cpu_stop, &arg);
+               tlb_migrate_finish(p->mm);
+               return 0;
+       }
+out:
+       task_rq_unlock(rq, p, &flags);
+
+       return ret;
+}
+EXPORT_SYMBOL_GPL(set_cpus_allowed_ptr);
+
+/*
+ * Move (not current) task off this cpu, onto dest cpu. We're doing
+ * this because either it can't run here any more (set_cpus_allowed()
+ * away from this CPU, or CPU going down), or because we're
+ * attempting to rebalance this task on exec (sched_exec).
+ *
+ * So we race with normal scheduler movements, but that's OK, as long
+ * as the task is no longer on this CPU.
+ *
+ * Returns non-zero if task was successfully migrated.
+ */
+static int __migrate_task(struct task_struct *p, int src_cpu, int dest_cpu)
+{
+       struct rq *rq_dest, *rq_src;
+       int ret = 0;
+
+       if (unlikely(!cpu_active(dest_cpu)))
+               return ret;
+
+       rq_src = cpu_rq(src_cpu);
+       rq_dest = cpu_rq(dest_cpu);
+
+       raw_spin_lock(&p->pi_lock);
+       double_rq_lock(rq_src, rq_dest);
+       /* Already moved. */
+       if (task_cpu(p) != src_cpu)
+               goto done;
+       /* Affinity changed (again). */
+       if (!cpumask_test_cpu(dest_cpu, tsk_cpus_allowed(p)))
+               goto fail;
+
+       /*
+        * If we're not on a rq, the next wake-up will ensure we're
+        * placed properly.
+        */
+       if (p->on_rq) {
+               dequeue_task(rq_src, p, 0);
+               set_task_cpu(p, dest_cpu);
+               enqueue_task(rq_dest, p, 0);
+               check_preempt_curr(rq_dest, p, 0);
+       }
+done:
+       ret = 1;
+fail:
+       double_rq_unlock(rq_src, rq_dest);
+       raw_spin_unlock(&p->pi_lock);
+       return ret;
+}
+
+/*
+ * migration_cpu_stop - this will be executed by a highprio stopper thread
+ * and performs thread migration by bumping thread off CPU then
+ * 'pushing' onto another runqueue.
+ */
+static int migration_cpu_stop(void *data)
+{
+       struct migration_arg *arg = data;
+
+       /*
+        * The original target cpu might have gone down and we might
+        * be on another cpu but it doesn't matter.
+        */
+       local_irq_disable();
+       __migrate_task(arg->task, raw_smp_processor_id(), arg->dest_cpu);
+       local_irq_enable();
+       return 0;
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+
+/*
+ * Ensures that the idle task is using init_mm right before its cpu goes
+ * offline.
+ */
+void idle_task_exit(void)
+{
+       struct mm_struct *mm = current->active_mm;
+
+       BUG_ON(cpu_online(smp_processor_id()));
+
+       if (mm != &init_mm)
+               switch_mm(mm, &init_mm, current);
+       mmdrop(mm);
+}
+
+/*
+ * Since this CPU is going 'away' for a while, fold any nr_active delta
+ * we might have. Assumes we're called after migrate_tasks() so that the
+ * nr_active count is stable.
+ *
+ * Also see the comment "Global load-average calculations".
+ */
+static void calc_load_migrate(struct rq *rq)
+{
+       long delta = calc_load_fold_active(rq);
+       if (delta)
+               atomic_long_add(delta, &calc_load_tasks);
+}
+
+/*
+ * Migrate all tasks from the rq, sleeping tasks will be migrated by
+ * try_to_wake_up()->select_task_rq().
+ *
+ * Called with rq->lock held even though we'er in stop_machine() and
+ * there's no concurrency possible, we hold the required locks anyway
+ * because of lock validation efforts.
+ */
+static void migrate_tasks(unsigned int dead_cpu)
+{
+       struct rq *rq = cpu_rq(dead_cpu);
+       struct task_struct *next, *stop = rq->stop;
+       int dest_cpu;
+
+       /*
+        * Fudge the rq selection such that the below task selection loop
+        * doesn't get stuck on the currently eligible stop task.
+        *
+        * We're currently inside stop_machine() and the rq is either stuck
+        * in the stop_machine_cpu_stop() loop, or we're executing this code,
+        * either way we should never end up calling schedule() until we're
+        * done here.
+        */
+       rq->stop = NULL;
+
+       for ( ; ; ) {
+               /*
+                * There's this thread running, bail when that's the only
+                * remaining thread.
+                */
+               if (rq->nr_running == 1)
+                       break;
+
+               next = pick_next_task(rq);
+               BUG_ON(!next);
+               next->sched_class->put_prev_task(rq, next);
+
+               /* Find suitable destination for @next, with force if needed. */
+               dest_cpu = select_fallback_rq(dead_cpu, next);
+               raw_spin_unlock(&rq->lock);
+
+               __migrate_task(next, dead_cpu, dest_cpu);
+
+               raw_spin_lock(&rq->lock);
+       }
+
+       rq->stop = stop;
+}
+
+#endif /* CONFIG_HOTPLUG_CPU */
+
+#if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SYSCTL)
+
+static struct ctl_table sd_ctl_dir[] = {
+       {
+               .procname       = "sched_domain",
+               .mode           = 0555,
+       },
+       {}
+};
+
+static struct ctl_table sd_ctl_root[] = {
+       {
+               .procname       = "kernel",
+               .mode           = 0555,
+               .child          = sd_ctl_dir,
+       },
+       {}
+};
+
+static struct ctl_table *sd_alloc_ctl_entry(int n)
+{
+       struct ctl_table *entry =
+               kcalloc(n, sizeof(struct ctl_table), GFP_KERNEL);
+
+       return entry;
+}
+
+static void sd_free_ctl_entry(struct ctl_table **tablep)
+{
+       struct ctl_table *entry;
+
+       /*
+        * In the intermediate directories, both the child directory and
+        * procname are dynamically allocated and could fail but the mode
+        * will always be set. In the lowest directory the names are
+        * static strings and all have proc handlers.
+        */
+       for (entry = *tablep; entry->mode; entry++) {
+               if (entry->child)
+                       sd_free_ctl_entry(&entry->child);
+               if (entry->proc_handler == NULL)
+                       kfree(entry->procname);
+       }
+
+       kfree(*tablep);
+       *tablep = NULL;
+}
+
+static int min_load_idx = 0;
+static int max_load_idx = CPU_LOAD_IDX_MAX-1;
+
+static void
+set_table_entry(struct ctl_table *entry,
+               const char *procname, void *data, int maxlen,
+               umode_t mode, proc_handler *proc_handler,
+               bool load_idx)
+{
+       entry->procname = procname;
+       entry->data = data;
+       entry->maxlen = maxlen;
+       entry->mode = mode;
+       entry->proc_handler = proc_handler;
+
+       if (load_idx) {
+               entry->extra1 = &min_load_idx;
+               entry->extra2 = &max_load_idx;
+       }
+}
+
+static struct ctl_table *
+sd_alloc_ctl_domain_table(struct sched_domain *sd)
+{
+       struct ctl_table *table = sd_alloc_ctl_entry(13);
+
+       if (table == NULL)
+               return NULL;
+
+       set_table_entry(&table[0], "min_interval", &sd->min_interval,
+               sizeof(long), 0644, proc_doulongvec_minmax, false);
+       set_table_entry(&table[1], "max_interval", &sd->max_interval,
+               sizeof(long), 0644, proc_doulongvec_minmax, false);
+       set_table_entry(&table[2], "busy_idx", &sd->busy_idx,
+               sizeof(int), 0644, proc_dointvec_minmax, true);
+       set_table_entry(&table[3], "idle_idx", &sd->idle_idx,
+               sizeof(int), 0644, proc_dointvec_minmax, true);
+       set_table_entry(&table[4], "newidle_idx", &sd->newidle_idx,
+               sizeof(int), 0644, proc_dointvec_minmax, true);
+       set_table_entry(&table[5], "wake_idx", &sd->wake_idx,
+               sizeof(int), 0644, proc_dointvec_minmax, true);
+       set_table_entry(&table[6], "forkexec_idx", &sd->forkexec_idx,
+               sizeof(int), 0644, proc_dointvec_minmax, true);
+       set_table_entry(&table[7], "busy_factor", &sd->busy_factor,
+               sizeof(int), 0644, proc_dointvec_minmax, false);
+       set_table_entry(&table[8], "imbalance_pct", &sd->imbalance_pct,
+               sizeof(int), 0644, proc_dointvec_minmax, false);
+       set_table_entry(&table[9], "cache_nice_tries",
+               &sd->cache_nice_tries,
+               sizeof(int), 0644, proc_dointvec_minmax, false);
+       set_table_entry(&table[10], "flags", &sd->flags,
+               sizeof(int), 0644, proc_dointvec_minmax, false);
+       set_table_entry(&table[11], "name", sd->name,
+               CORENAME_MAX_SIZE, 0444, proc_dostring, false);
+       /* &table[12] is terminator */
+
+       return table;
+}
+
+static ctl_table *sd_alloc_ctl_cpu_table(int cpu)
+{
+       struct ctl_table *entry, *table;
+       struct sched_domain *sd;
+       int domain_num = 0, i;
+       char buf[32];
+
+       for_each_domain(cpu, sd)
+               domain_num++;
+       entry = table = sd_alloc_ctl_entry(domain_num + 1);
+       if (table == NULL)
+               return NULL;
+
+       i = 0;
+       for_each_domain(cpu, sd) {
+               snprintf(buf, 32, "domain%d", i);
+               entry->procname = kstrdup(buf, GFP_KERNEL);
+               entry->mode = 0555;
+               entry->child = sd_alloc_ctl_domain_table(sd);
+               entry++;
+               i++;
+       }
+       return table;
+}
+
+static struct ctl_table_header *sd_sysctl_header;
+static void register_sched_domain_sysctl(void)
+{
+       int i, cpu_num = num_possible_cpus();
+       struct ctl_table *entry = sd_alloc_ctl_entry(cpu_num + 1);
+       char buf[32];
+
+       WARN_ON(sd_ctl_dir[0].child);
+       sd_ctl_dir[0].child = entry;
+
+       if (entry == NULL)
+               return;
+
+       for_each_possible_cpu(i) {
+               snprintf(buf, 32, "cpu%d", i);
+               entry->procname = kstrdup(buf, GFP_KERNEL);
+               entry->mode = 0555;
+               entry->child = sd_alloc_ctl_cpu_table(i);
+               entry++;
+       }
+
+       WARN_ON(sd_sysctl_header);
+       sd_sysctl_header = register_sysctl_table(sd_ctl_root);
+}
+
+/* may be called multiple times per register */
+static void unregister_sched_domain_sysctl(void)
+{
+       if (sd_sysctl_header)
+               unregister_sysctl_table(sd_sysctl_header);
+       sd_sysctl_header = NULL;
+       if (sd_ctl_dir[0].child)
+               sd_free_ctl_entry(&sd_ctl_dir[0].child);
+}
+#else
+static void register_sched_domain_sysctl(void)
+{
+}
+static void unregister_sched_domain_sysctl(void)
+{
+}
+#endif
+
+static void set_rq_online(struct rq *rq)
+{
+       if (!rq->online) {
+               const struct sched_class *class;
+
+               cpumask_set_cpu(rq->cpu, rq->rd->online);
+               rq->online = 1;
+
+               for_each_class(class) {
+                       if (class->rq_online)
+                               class->rq_online(rq);
+               }
+       }
+}
+
+static void set_rq_offline(struct rq *rq)
+{
+       if (rq->online) {
+               const struct sched_class *class;
+
+               for_each_class(class) {
+                       if (class->rq_offline)
+                               class->rq_offline(rq);
+               }
+
+               cpumask_clear_cpu(rq->cpu, rq->rd->online);
+               rq->online = 0;
+       }
+}
+
+/*
+ * migration_call - callback that gets triggered when a CPU is added.
+ * Here we can start up the necessary migration thread for the new CPU.
+ */
+static int __cpuinit
+migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
+{
+       int cpu = (long)hcpu;
+       unsigned long flags;
+       struct rq *rq = cpu_rq(cpu);
+
+       switch (action & ~CPU_TASKS_FROZEN) {
+
+       case CPU_UP_PREPARE:
+               rq->calc_load_update = calc_load_update;
+               break;
+
+       case CPU_ONLINE:
+               /* Update our root-domain */
+               raw_spin_lock_irqsave(&rq->lock, flags);
+               if (rq->rd) {
+                       BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span));
+
+                       set_rq_online(rq);
+               }
+               raw_spin_unlock_irqrestore(&rq->lock, flags);
+               break;
+
+#ifdef CONFIG_HOTPLUG_CPU
+       case CPU_DYING:
+               sched_ttwu_pending();
+               /* Update our root-domain */
+               raw_spin_lock_irqsave(&rq->lock, flags);
+               if (rq->rd) {
+                       BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span));
+                       set_rq_offline(rq);
+               }
+               migrate_tasks(cpu);
+               BUG_ON(rq->nr_running != 1); /* the migration thread */
+               raw_spin_unlock_irqrestore(&rq->lock, flags);
+               break;
+
+       case CPU_DEAD:
+               calc_load_migrate(rq);
+               break;
+#endif
+       }
+
+       update_max_interval();
+
+       return NOTIFY_OK;
+}
+
+/*
+ * Register at high priority so that task migration (migrate_all_tasks)
+ * happens before everything else.  This has to be lower priority than
+ * the notifier in the perf_event subsystem, though.
+ */
+static struct notifier_block __cpuinitdata migration_notifier = {
+       .notifier_call = migration_call,
+       .priority = CPU_PRI_MIGRATION,
+};
+
+static int __cpuinit sched_cpu_active(struct notifier_block *nfb,
+                                     unsigned long action, void *hcpu)
+{
+       switch (action & ~CPU_TASKS_FROZEN) {
+       case CPU_STARTING:
+       case CPU_DOWN_FAILED:
+               set_cpu_active((long)hcpu, true);
+               return NOTIFY_OK;
+       default:
+               return NOTIFY_DONE;
+       }
+}
+
+static int __cpuinit sched_cpu_inactive(struct notifier_block *nfb,
+                                       unsigned long action, void *hcpu)
+{
+       switch (action & ~CPU_TASKS_FROZEN) {
+       case CPU_DOWN_PREPARE:
+               set_cpu_active((long)hcpu, false);
+               return NOTIFY_OK;
+       default:
+               return NOTIFY_DONE;
+       }
+}
+
+static int __init migration_init(void)
+{
+       void *cpu = (void *)(long)smp_processor_id();
+       int err;
+
+       /* Initialize migration for the boot CPU */
+       err = migration_call(&migration_notifier, CPU_UP_PREPARE, cpu);
+       BUG_ON(err == NOTIFY_BAD);
+       migration_call(&migration_notifier, CPU_ONLINE, cpu);
+       register_cpu_notifier(&migration_notifier);
+
+       /* Register cpu active notifiers */
+       cpu_notifier(sched_cpu_active, CPU_PRI_SCHED_ACTIVE);
+       cpu_notifier(sched_cpu_inactive, CPU_PRI_SCHED_INACTIVE);
+
+       return 0;
+}
+early_initcall(migration_init);
+#endif
+
+#ifdef CONFIG_SMP
+
+static cpumask_var_t sched_domains_tmpmask; /* sched_domains_mutex */
+
+#ifdef CONFIG_SCHED_DEBUG
+
+static __read_mostly int sched_debug_enabled;
+
+static int __init sched_debug_setup(char *str)
+{
+       sched_debug_enabled = 1;
+
+       return 0;
+}
+early_param("sched_debug", sched_debug_setup);
+
+static inline bool sched_debug(void)
+{
+       return sched_debug_enabled;
+}
+
+static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level,
+                                 struct cpumask *groupmask)
+{
+       struct sched_group *group = sd->groups;
+       char str[256];
+
+       cpulist_scnprintf(str, sizeof(str), sched_domain_span(sd));
+       cpumask_clear(groupmask);
+
+       printk(KERN_DEBUG "%*s domain %d: ", level, "", level);
+
+       if (!(sd->flags & SD_LOAD_BALANCE)) {
+               printk("does not load-balance\n");
+               if (sd->parent)
+                       printk(KERN_ERR "ERROR: !SD_LOAD_BALANCE domain"
+                                       " has parent");
+               return -1;
+       }
+
+       printk(KERN_CONT "span %s level %s\n", str, sd->name);
+
+       if (!cpumask_test_cpu(cpu, sched_domain_span(sd))) {
+               printk(KERN_ERR "ERROR: domain->span does not contain "
+                               "CPU%d\n", cpu);
+       }
+       if (!cpumask_test_cpu(cpu, sched_group_cpus(group))) {
+               printk(KERN_ERR "ERROR: domain->groups does not contain"
+                               " CPU%d\n", cpu);
+       }
+
+       printk(KERN_DEBUG "%*s groups:", level + 1, "");
+       do {
+               if (!group) {
+                       printk("\n");
+                       printk(KERN_ERR "ERROR: group is NULL\n");
+                       break;
+               }
+
+               /*
+                * Even though we initialize ->power to something semi-sane,
+                * we leave power_orig unset. This allows us to detect if
+                * domain iteration is still funny without causing /0 traps.
+                */
+               if (!group->sgp->power_orig) {
+                       printk(KERN_CONT "\n");
+                       printk(KERN_ERR "ERROR: domain->cpu_power not "
+                                       "set\n");
+                       break;
+               }
+
+               if (!cpumask_weight(sched_group_cpus(group))) {
+                       printk(KERN_CONT "\n");
+                       printk(KERN_ERR "ERROR: empty group\n");
+                       break;
+               }
+
+               if (!(sd->flags & SD_OVERLAP) &&
+                   cpumask_intersects(groupmask, sched_group_cpus(group))) {
+                       printk(KERN_CONT "\n");
+                       printk(KERN_ERR "ERROR: repeated CPUs\n");
+                       break;
+               }
+
+               cpumask_or(groupmask, groupmask, sched_group_cpus(group));
+
+               cpulist_scnprintf(str, sizeof(str), sched_group_cpus(group));
+
+               printk(KERN_CONT " %s", str);
+               if (group->sgp->power != SCHED_POWER_SCALE) {
+                       printk(KERN_CONT " (cpu_power = %d)",
+                               group->sgp->power);
+               }
+
+               group = group->next;
+       } while (group != sd->groups);
+       printk(KERN_CONT "\n");
+
+       if (!cpumask_equal(sched_domain_span(sd), groupmask))
+               printk(KERN_ERR "ERROR: groups don't span domain->span\n");
+
+       if (sd->parent &&
+           !cpumask_subset(groupmask, sched_domain_span(sd->parent)))
+               printk(KERN_ERR "ERROR: parent span is not a superset "
+                       "of domain->span\n");
+       return 0;
+}
+
+static void sched_domain_debug(struct sched_domain *sd, int cpu)
+{
+       int level = 0;
+
+       if (!sched_debug_enabled)
+               return;
+
+       if (!sd) {
+               printk(KERN_DEBUG "CPU%d attaching NULL sched-domain.\n", cpu);
+               return;
+       }
+
+       printk(KERN_DEBUG "CPU%d attaching sched-domain:\n", cpu);
+
+       for (;;) {
+               if (sched_domain_debug_one(sd, cpu, level, sched_domains_tmpmask))
+                       break;
+               level++;
+               sd = sd->parent;
+               if (!sd)
+                       break;
+       }
+}
+#else /* !CONFIG_SCHED_DEBUG */
+# define sched_domain_debug(sd, cpu) do { } while (0)
+static inline bool sched_debug(void)
+{
+       return false;
+}
+#endif /* CONFIG_SCHED_DEBUG */
+
+static int sd_degenerate(struct sched_domain *sd)
+{
+       if (cpumask_weight(sched_domain_span(sd)) == 1)
+               return 1;
+
+       /* Following flags need at least 2 groups */
+       if (sd->flags & (SD_LOAD_BALANCE |
+                        SD_BALANCE_NEWIDLE |
+                        SD_BALANCE_FORK |
+                        SD_BALANCE_EXEC |
+                        SD_SHARE_CPUPOWER |
+                        SD_SHARE_PKG_RESOURCES)) {
+               if (sd->groups != sd->groups->next)
+                       return 0;
+       }
+
+       /* Following flags don't use groups */
+       if (sd->flags & (SD_WAKE_AFFINE))
+               return 0;
+
+       return 1;
+}
+
+static int
+sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent)
+{
+       unsigned long cflags = sd->flags, pflags = parent->flags;
+
+       if (sd_degenerate(parent))
+               return 1;
+
+       if (!cpumask_equal(sched_domain_span(sd), sched_domain_span(parent)))
+               return 0;
+
+       /* Flags needing groups don't count if only 1 group in parent */
+       if (parent->groups == parent->groups->next) {
+               pflags &= ~(SD_LOAD_BALANCE |
+                               SD_BALANCE_NEWIDLE |
+                               SD_BALANCE_FORK |
+                               SD_BALANCE_EXEC |
+                               SD_SHARE_CPUPOWER |
+                               SD_SHARE_PKG_RESOURCES);
+               if (nr_node_ids == 1)
+                       pflags &= ~SD_SERIALIZE;
+       }
+       if (~cflags & pflags)
+               return 0;
+
+       return 1;
+}
+
+static void free_rootdomain(struct rcu_head *rcu)
+{
+       struct root_domain *rd = container_of(rcu, struct root_domain, rcu);
+
+       cpupri_cleanup(&rd->cpupri);
+       free_cpumask_var(rd->rto_mask);
+       free_cpumask_var(rd->online);
+       free_cpumask_var(rd->span);
+       kfree(rd);
+}
+
+static void rq_attach_root(struct rq *rq, struct root_domain *rd)
+{
+       struct root_domain *old_rd = NULL;
+       unsigned long flags;
+
+       raw_spin_lock_irqsave(&rq->lock, flags);
+
+       if (rq->rd) {
+               old_rd = rq->rd;
+
+               if (cpumask_test_cpu(rq->cpu, old_rd->online))
+                       set_rq_offline(rq);
+
+               cpumask_clear_cpu(rq->cpu, old_rd->span);
+
+               /*
+                * If we dont want to free the old_rt yet then
+                * set old_rd to NULL to skip the freeing later
+                * in this function:
+                */
+               if (!atomic_dec_and_test(&old_rd->refcount))
+                       old_rd = NULL;
+       }
+
+       atomic_inc(&rd->refcount);
+       rq->rd = rd;
+
+       cpumask_set_cpu(rq->cpu, rd->span);
+       if (cpumask_test_cpu(rq->cpu, cpu_active_mask))
+               set_rq_online(rq);
+
+       raw_spin_unlock_irqrestore(&rq->lock, flags);
+
+       if (old_rd)
+               call_rcu_sched(&old_rd->rcu, free_rootdomain);
+}
+
+static int init_rootdomain(struct root_domain *rd)
+{
+       memset(rd, 0, sizeof(*rd));
+
+       if (!alloc_cpumask_var(&rd->span, GFP_KERNEL))
+               goto out;
+       if (!alloc_cpumask_var(&rd->online, GFP_KERNEL))
+               goto free_span;
+       if (!alloc_cpumask_var(&rd->rto_mask, GFP_KERNEL))
+               goto free_online;
+
+       if (cpupri_init(&rd->cpupri) != 0)
+               goto free_rto_mask;
+       return 0;
+
+free_rto_mask:
+       free_cpumask_var(rd->rto_mask);
+free_online:
+       free_cpumask_var(rd->online);
+free_span:
+       free_cpumask_var(rd->span);
+out:
+       return -ENOMEM;
+}
+
+/*
+ * By default the system creates a single root-domain with all cpus as
+ * members (mimicking the global state we have today).
+ */
+struct root_domain def_root_domain;
+
+static void init_defrootdomain(void)
+{
+       init_rootdomain(&def_root_domain);
+
+       atomic_set(&def_root_domain.refcount, 1);
+}
+
+static struct root_domain *alloc_rootdomain(void)
+{
+       struct root_domain *rd;
+
+       rd = kmalloc(sizeof(*rd), GFP_KERNEL);
+       if (!rd)
+               return NULL;
+
+       if (init_rootdomain(rd) != 0) {
+               kfree(rd);
+               return NULL;
+       }
+
+       return rd;
+}
+
+static void free_sched_groups(struct sched_group *sg, int free_sgp)
+{
+       struct sched_group *tmp, *first;
+
+       if (!sg)
+               return;
+
+       first = sg;
+       do {
+               tmp = sg->next;
+
+               if (free_sgp && atomic_dec_and_test(&sg->sgp->ref))
+                       kfree(sg->sgp);
+
+               kfree(sg);
+               sg = tmp;
+       } while (sg != first);
+}
+
+static void free_sched_domain(struct rcu_head *rcu)
+{
+       struct sched_domain *sd = container_of(rcu, struct sched_domain, rcu);
+
+       /*
+        * If its an overlapping domain it has private groups, iterate and
+        * nuke them all.
+        */
+       if (sd->flags & SD_OVERLAP) {
+               free_sched_groups(sd->groups, 1);
+       } else if (atomic_dec_and_test(&sd->groups->ref)) {
+               kfree(sd->groups->sgp);
+               kfree(sd->groups);
+       }
+       kfree(sd);
+}
+
+static void destroy_sched_domain(struct sched_domain *sd, int cpu)
+{
+       call_rcu(&sd->rcu, free_sched_domain);
+}
+
+static void destroy_sched_domains(struct sched_domain *sd, int cpu)
+{
+       for (; sd; sd = sd->parent)
+               destroy_sched_domain(sd, cpu);
+}
+
+/*
+ * Keep a special pointer to the highest sched_domain that has
+ * SD_SHARE_PKG_RESOURCE set (Last Level Cache Domain) for this
+ * allows us to avoid some pointer chasing select_idle_sibling().
+ *
+ * Also keep a unique ID per domain (we use the first cpu number in
+ * the cpumask of the domain), this allows us to quickly tell if
+ * two cpus are in the same cache domain, see cpus_share_cache().
+ */
+DEFINE_PER_CPU(struct sched_domain *, sd_llc);
+DEFINE_PER_CPU(int, sd_llc_id);
+
+static void update_top_cache_domain(int cpu)
+{
+       struct sched_domain *sd;
+       int id = cpu;
+
+       sd = highest_flag_domain(cpu, SD_SHARE_PKG_RESOURCES);
+       if (sd)
+               id = cpumask_first(sched_domain_span(sd));
+
+       rcu_assign_pointer(per_cpu(sd_llc, cpu), sd);
+       per_cpu(sd_llc_id, cpu) = id;
+}
+
+/*
+ * Attach the domain 'sd' to 'cpu' as its base domain. Callers must
+ * hold the hotplug lock.
+ */
+static void
+cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu)
+{
+       struct rq *rq = cpu_rq(cpu);
+       struct sched_domain *tmp;
+
+       /* Remove the sched domains which do not contribute to scheduling. */
+       for (tmp = sd; tmp; ) {
+               struct sched_domain *parent = tmp->parent;
+               if (!parent)
+                       break;
+
+               if (sd_parent_degenerate(tmp, parent)) {
+                       tmp->parent = parent->parent;
+                       if (parent->parent)
+                               parent->parent->child = tmp;
+                       destroy_sched_domain(parent, cpu);
+               } else
+                       tmp = tmp->parent;
+       }
+
+       if (sd && sd_degenerate(sd)) {
+               tmp = sd;
+               sd = sd->parent;
+               destroy_sched_domain(tmp, cpu);
+               if (sd)
+                       sd->child = NULL;
+       }
+
+       sched_domain_debug(sd, cpu);
+
+       rq_attach_root(rq, rd);
+       tmp = rq->sd;
+       rcu_assign_pointer(rq->sd, sd);
+       destroy_sched_domains(tmp, cpu);
+
+       update_top_cache_domain(cpu);
+}
+
+/* cpus with isolated domains */
+static cpumask_var_t cpu_isolated_map;
+
+/* Setup the mask of cpus configured for isolated domains */
+static int __init isolated_cpu_setup(char *str)
+{
+       alloc_bootmem_cpumask_var(&cpu_isolated_map);
+       cpulist_parse(str, cpu_isolated_map);
+       return 1;
+}
+
+__setup("isolcpus=", isolated_cpu_setup);
+
+static const struct cpumask *cpu_cpu_mask(int cpu)
+{
+       return cpumask_of_node(cpu_to_node(cpu));
+}
+
+struct sd_data {
+       struct sched_domain **__percpu sd;
+       struct sched_group **__percpu sg;
+       struct sched_group_power **__percpu sgp;
+};
+
+struct s_data {
+       struct sched_domain ** __percpu sd;
+       struct root_domain      *rd;
+};
+
+enum s_alloc {
+       sa_rootdomain,
+       sa_sd,
+       sa_sd_storage,
+       sa_none,
+};
+
+struct sched_domain_topology_level;
+
+typedef struct sched_domain *(*sched_domain_init_f)(struct sched_domain_topology_level *tl, int cpu);
+typedef const struct cpumask *(*sched_domain_mask_f)(int cpu);
+
+#define SDTL_OVERLAP   0x01
+
+struct sched_domain_topology_level {
+       sched_domain_init_f init;
+       sched_domain_mask_f mask;
+       int                 flags;
+       int                 numa_level;
+       struct sd_data      data;
+};
+
+/*
+ * Build an iteration mask that can exclude certain CPUs from the upwards
+ * domain traversal.
+ *
+ * Asymmetric node setups can result in situations where the domain tree is of
+ * unequal depth, make sure to skip domains that already cover the entire
+ * range.
+ *
+ * In that case build_sched_domains() will have terminated the iteration early
+ * and our sibling sd spans will be empty. Domains should always include the
+ * cpu they're built on, so check that.
+ *
+ */
+static void build_group_mask(struct sched_domain *sd, struct sched_group *sg)
+{
+       const struct cpumask *span = sched_domain_span(sd);
+       struct sd_data *sdd = sd->private;
+       struct sched_domain *sibling;
+       int i;
+
+       for_each_cpu(i, span) {
+               sibling = *per_cpu_ptr(sdd->sd, i);
+               if (!cpumask_test_cpu(i, sched_domain_span(sibling)))
+                       continue;
+
+               cpumask_set_cpu(i, sched_group_mask(sg));
+       }
+}
+
+/*
+ * Return the canonical balance cpu for this group, this is the first cpu
+ * of this group that's also in the iteration mask.
+ */
+int group_balance_cpu(struct sched_group *sg)
+{
+       return cpumask_first_and(sched_group_cpus(sg), sched_group_mask(sg));
+}
+
+static int
+build_overlap_sched_groups(struct sched_domain *sd, int cpu)
+{
+       struct sched_group *first = NULL, *last = NULL, *groups = NULL, *sg;
+       const struct cpumask *span = sched_domain_span(sd);
+       struct cpumask *covered = sched_domains_tmpmask;
+       struct sd_data *sdd = sd->private;
+       struct sched_domain *child;
+       int i;
+
+       cpumask_clear(covered);
+
+       for_each_cpu(i, span) {
+               struct cpumask *sg_span;
+
+               if (cpumask_test_cpu(i, covered))
+                       continue;
+
+               child = *per_cpu_ptr(sdd->sd, i);
+
+               /* See the comment near build_group_mask(). */
+               if (!cpumask_test_cpu(i, sched_domain_span(child)))
+                       continue;
+
+               sg = kzalloc_node(sizeof(struct sched_group) + cpumask_size(),
+                               GFP_KERNEL, cpu_to_node(cpu));
+
+               if (!sg)
+                       goto fail;
+
+               sg_span = sched_group_cpus(sg);
+               if (child->child) {
+                       child = child->child;
+                       cpumask_copy(sg_span, sched_domain_span(child));
+               } else
+                       cpumask_set_cpu(i, sg_span);
+
+               cpumask_or(covered, covered, sg_span);
+
+               sg->sgp = *per_cpu_ptr(sdd->sgp, i);
+               if (atomic_inc_return(&sg->sgp->ref) == 1)
+                       build_group_mask(sd, sg);
+
+               /*
+                * Initialize sgp->power such that even if we mess up the
+                * domains and no possible iteration will get us here, we won't
+                * die on a /0 trap.
+                */
+               sg->sgp->power = SCHED_POWER_SCALE * cpumask_weight(sg_span);
+
+               /*
+                * Make sure the first group of this domain contains the
+                * canonical balance cpu. Otherwise the sched_domain iteration
+                * breaks. See update_sg_lb_stats().
+                */
+               if ((!groups && cpumask_test_cpu(cpu, sg_span)) ||
+                   group_balance_cpu(sg) == cpu)
+                       groups = sg;
+
+               if (!first)
+                       first = sg;
+               if (last)
+                       last->next = sg;
+               last = sg;
+               last->next = first;
+       }
+       sd->groups = groups;
+
+       return 0;
+
+fail:
+       free_sched_groups(first, 0);
+
+       return -ENOMEM;
+}
+
+static int get_group(int cpu, struct sd_data *sdd, struct sched_group **sg)
+{
+       struct sched_domain *sd = *per_cpu_ptr(sdd->sd, cpu);
+       struct sched_domain *child = sd->child;
+
+       if (child)
+               cpu = cpumask_first(sched_domain_span(child));
+
+       if (sg) {
+               *sg = *per_cpu_ptr(sdd->sg, cpu);
+               (*sg)->sgp = *per_cpu_ptr(sdd->sgp, cpu);
+               atomic_set(&(*sg)->sgp->ref, 1); /* for claim_allocations */
+       }
+
+       return cpu;
+}
+
+/*
+ * build_sched_groups will build a circular linked list of the groups
+ * covered by the given span, and will set each group's ->cpumask correctly,
+ * and ->cpu_power to 0.
+ *
+ * Assumes the sched_domain tree is fully constructed
+ */
+static int
+build_sched_groups(struct sched_domain *sd, int cpu)
+{
+       struct sched_group *first = NULL, *last = NULL;
+       struct sd_data *sdd = sd->private;
+       const struct cpumask *span = sched_domain_span(sd);
+       struct cpumask *covered;
+       int i;
+
+       get_group(cpu, sdd, &sd->groups);
+       atomic_inc(&sd->groups->ref);
+
+       if (cpu != cpumask_first(sched_domain_span(sd)))
+               return 0;
+
+       lockdep_assert_held(&sched_domains_mutex);
+       covered = sched_domains_tmpmask;
+
+       cpumask_clear(covered);
+
+       for_each_cpu(i, span) {
+               struct sched_group *sg;
+               int group = get_group(i, sdd, &sg);
+               int j;
+
+               if (cpumask_test_cpu(i, covered))
+                       continue;
+
+               cpumask_clear(sched_group_cpus(sg));
+               sg->sgp->power = 0;
+               cpumask_setall(sched_group_mask(sg));
+
+               for_each_cpu(j, span) {
+                       if (get_group(j, sdd, NULL) != group)
+                               continue;
+
+                       cpumask_set_cpu(j, covered);
+                       cpumask_set_cpu(j, sched_group_cpus(sg));
+               }
+
+               if (!first)
+                       first = sg;
+               if (last)
+                       last->next = sg;
+               last = sg;
+       }
+       last->next = first;
+
+       return 0;
+}
+
+/*
+ * Initialize sched groups cpu_power.
+ *
+ * cpu_power indicates the capacity of sched group, which is used while
+ * distributing the load between different sched groups in a sched domain.
+ * Typically cpu_power for all the groups in a sched domain will be same unless
+ * there are asymmetries in the topology. If there are asymmetries, group
+ * having more cpu_power will pickup more load compared to the group having
+ * less cpu_power.
+ */
+static void init_sched_groups_power(int cpu, struct sched_domain *sd)
+{
+       struct sched_group *sg = sd->groups;
+
+       WARN_ON(!sd || !sg);
+
+       do {
+               sg->group_weight = cpumask_weight(sched_group_cpus(sg));
+               sg = sg->next;
+       } while (sg != sd->groups);
+
+       if (cpu != group_balance_cpu(sg))
+               return;
+
+       update_group_power(sd, cpu);
+       atomic_set(&sg->sgp->nr_busy_cpus, sg->group_weight);
+}
+
+int __weak arch_sd_sibling_asym_packing(void)
+{
+       return 0*SD_ASYM_PACKING;
+}
+
+/*
+ * Initializers for schedule domains
+ * Non-inlined to reduce accumulated stack pressure in build_sched_domains()
+ */
+
+#ifdef CONFIG_SCHED_DEBUG
+# define SD_INIT_NAME(sd, type)                sd->name = #type
+#else
+# define SD_INIT_NAME(sd, type)                do { } while (0)
+#endif
+
+#define SD_INIT_FUNC(type)                                             \
+static noinline struct sched_domain *                                  \
+sd_init_##type(struct sched_domain_topology_level *tl, int cpu)        \
+{                                                                      \
+       struct sched_domain *sd = *per_cpu_ptr(tl->data.sd, cpu);       \
+       *sd = SD_##type##_INIT;                                         \
+       SD_INIT_NAME(sd, type);                                         \
+       sd->private = &tl->data;                                        \
+       return sd;                                                      \
+}
+
+SD_INIT_FUNC(CPU)
+#ifdef CONFIG_SCHED_SMT
+ SD_INIT_FUNC(SIBLING)
+#endif
+#ifdef CONFIG_SCHED_MC
+ SD_INIT_FUNC(MC)
+#endif
+#ifdef CONFIG_SCHED_BOOK
+ SD_INIT_FUNC(BOOK)
+#endif
+
+static int default_relax_domain_level = -1;
+int sched_domain_level_max;
+
+static int __init setup_relax_domain_level(char *str)
+{
+       if (kstrtoint(str, 0, &default_relax_domain_level))
+               pr_warn("Unable to set relax_domain_level\n");
+
+       return 1;
+}
+__setup("relax_domain_level=", setup_relax_domain_level);
+
+static void set_domain_attribute(struct sched_domain *sd,
+                                struct sched_domain_attr *attr)
+{
+       int request;
+
+       if (!attr || attr->relax_domain_level < 0) {
+               if (default_relax_domain_level < 0)
+                       return;
+               else
+                       request = default_relax_domain_level;
+       } else
+               request = attr->relax_domain_level;
+       if (request < sd->level) {
+               /* turn off idle balance on this domain */
+               sd->flags &= ~(SD_BALANCE_WAKE|SD_BALANCE_NEWIDLE);
+       } else {
+               /* turn on idle balance on this domain */
+               sd->flags |= (SD_BALANCE_WAKE|SD_BALANCE_NEWIDLE);
+       }
+}
+
+static void __sdt_free(const struct cpumask *cpu_map);
+static int __sdt_alloc(const struct cpumask *cpu_map);
+
+static void __free_domain_allocs(struct s_data *d, enum s_alloc what,
+                                const struct cpumask *cpu_map)
+{
+       switch (what) {
+       case sa_rootdomain:
+               if (!atomic_read(&d->rd->refcount))
+                       free_rootdomain(&d->rd->rcu); /* fall through */
+       case sa_sd:
+               free_percpu(d->sd); /* fall through */
+       case sa_sd_storage:
+               __sdt_free(cpu_map); /* fall through */
+       case sa_none:
+               break;
+       }
+}
+
+static enum s_alloc __visit_domain_allocation_hell(struct s_data *d,
+                                                  const struct cpumask *cpu_map)
+{
+       memset(d, 0, sizeof(*d));
+
+       if (__sdt_alloc(cpu_map))
+               return sa_sd_storage;
+       d->sd = alloc_percpu(struct sched_domain *);
+       if (!d->sd)
+               return sa_sd_storage;
+       d->rd = alloc_rootdomain();
+       if (!d->rd)
+               return sa_sd;
+       return sa_rootdomain;
+}
+
+/*
+ * NULL the sd_data elements we've used to build the sched_domain and
+ * sched_group structure so that the subsequent __free_domain_allocs()
+ * will not free the data we're using.
+ */
+static void claim_allocations(int cpu, struct sched_domain *sd)
+{
+       struct sd_data *sdd = sd->private;
+
+       WARN_ON_ONCE(*per_cpu_ptr(sdd->sd, cpu) != sd);
+       *per_cpu_ptr(sdd->sd, cpu) = NULL;
+
+       if (atomic_read(&(*per_cpu_ptr(sdd->sg, cpu))->ref))
+               *per_cpu_ptr(sdd->sg, cpu) = NULL;
+
+       if (atomic_read(&(*per_cpu_ptr(sdd->sgp, cpu))->ref))
+               *per_cpu_ptr(sdd->sgp, cpu) = NULL;
+}
+
+#ifdef CONFIG_SCHED_SMT
+static const struct cpumask *cpu_smt_mask(int cpu)
+{
+       return topology_thread_cpumask(cpu);
+}
+#endif
+
+/*
+ * Topology list, bottom-up.
+ */
+static struct sched_domain_topology_level default_topology[] = {
+#ifdef CONFIG_SCHED_SMT
+       { sd_init_SIBLING, cpu_smt_mask, },
+#endif
+#ifdef CONFIG_SCHED_MC
+       { sd_init_MC, cpu_coregroup_mask, },
+#endif
+#ifdef CONFIG_SCHED_BOOK
+       { sd_init_BOOK, cpu_book_mask, },
+#endif
+       { sd_init_CPU, cpu_cpu_mask, },
+       { NULL, },
+};
+
+static struct sched_domain_topology_level *sched_domain_topology = default_topology;
+
+#ifdef CONFIG_NUMA
+
+static int sched_domains_numa_levels;
+static int *sched_domains_numa_distance;
+static struct cpumask ***sched_domains_numa_masks;
+static int sched_domains_curr_level;
+
+static inline int sd_local_flags(int level)
+{
+       if (sched_domains_numa_distance[level] > RECLAIM_DISTANCE)
+               return 0;
+
+       return SD_BALANCE_EXEC | SD_BALANCE_FORK | SD_WAKE_AFFINE;
+}
+
+static struct sched_domain *
+sd_numa_init(struct sched_domain_topology_level *tl, int cpu)
+{
+       struct sched_domain *sd = *per_cpu_ptr(tl->data.sd, cpu);
+       int level = tl->numa_level;
+       int sd_weight = cpumask_weight(
+                       sched_domains_numa_masks[level][cpu_to_node(cpu)]);
+
+       *sd = (struct sched_domain){
+               .min_interval           = sd_weight,
+               .max_interval           = 2*sd_weight,
+               .busy_factor            = 32,
+               .imbalance_pct          = 125,
+               .cache_nice_tries       = 2,
+               .busy_idx               = 3,
+               .idle_idx               = 2,
+               .newidle_idx            = 0,
+               .wake_idx               = 0,
+               .forkexec_idx           = 0,
+
+               .flags                  = 1*SD_LOAD_BALANCE
+                                       | 1*SD_BALANCE_NEWIDLE
+                                       | 0*SD_BALANCE_EXEC
+                                       | 0*SD_BALANCE_FORK
+                                       | 0*SD_BALANCE_WAKE
+                                       | 0*SD_WAKE_AFFINE
+                                       | 0*SD_SHARE_CPUPOWER
+                                       | 0*SD_SHARE_PKG_RESOURCES
+                                       | 1*SD_SERIALIZE
+                                       | 0*SD_PREFER_SIBLING
+                                       | sd_local_flags(level)
+                                       ,
+               .last_balance           = jiffies,
+               .balance_interval       = sd_weight,
+       };
+       SD_INIT_NAME(sd, NUMA);
+       sd->private = &tl->data;
+
+       /*
+        * Ugly hack to pass state to sd_numa_mask()...
+        */
+       sched_domains_curr_level = tl->numa_level;
+
+       return sd;
+}
+
+static const struct cpumask *sd_numa_mask(int cpu)
+{
+       return sched_domains_numa_masks[sched_domains_curr_level][cpu_to_node(cpu)];
+}
+
+static void sched_numa_warn(const char *str)
+{
+       static int done = false;
+       int i,j;
+
+       if (done)
+               return;
+
+       done = true;
+
+       printk(KERN_WARNING "ERROR: %s\n\n", str);
+
+       for (i = 0; i < nr_node_ids; i++) {
+               printk(KERN_WARNING "  ");
+               for (j = 0; j < nr_node_ids; j++)
+                       printk(KERN_CONT "%02d ", node_distance(i,j));
+               printk(KERN_CONT "\n");
+       }
+       printk(KERN_WARNING "\n");
+}
+
+static bool find_numa_distance(int distance)
+{
+       int i;
+
+       if (distance == node_distance(0, 0))
+               return true;
+
+       for (i = 0; i < sched_domains_numa_levels; i++) {
+               if (sched_domains_numa_distance[i] == distance)
+                       return true;
+       }
+
+       return false;
+}
+
+static void sched_init_numa(void)
+{
+       int next_distance, curr_distance = node_distance(0, 0);
+       struct sched_domain_topology_level *tl;
+       int level = 0;
+       int i, j, k;
+
+       sched_domains_numa_distance = kzalloc(sizeof(int) * nr_node_ids, GFP_KERNEL);
+       if (!sched_domains_numa_distance)
+               return;
+
+       /*
+        * O(nr_nodes^2) deduplicating selection sort -- in order to find the
+        * unique distances in the node_distance() table.
+        *
+        * Assumes node_distance(0,j) includes all distances in
+        * node_distance(i,j) in order to avoid cubic time.
+        */
+       next_distance = curr_distance;
+       for (i = 0; i < nr_node_ids; i++) {
+               for (j = 0; j < nr_node_ids; j++) {
+                       for (k = 0; k < nr_node_ids; k++) {
+                               int distance = node_distance(i, k);
+
+                               if (distance > curr_distance &&
+                                   (distance < next_distance ||
+                                    next_distance == curr_distance))
+                                       next_distance = distance;
+
+                               /*
+                                * While not a strong assumption it would be nice to know
+                                * about cases where if node A is connected to B, B is not
+                                * equally connected to A.
+                                */
+                               if (sched_debug() && node_distance(k, i) != distance)
+                                       sched_numa_warn("Node-distance not symmetric");
+
+                               if (sched_debug() && i && !find_numa_distance(distance))
+                                       sched_numa_warn("Node-0 not representative");
+                       }
+                       if (next_distance != curr_distance) {
+                               sched_domains_numa_distance[level++] = next_distance;
+                               sched_domains_numa_levels = level;
+                               curr_distance = next_distance;
+                       } else break;
+               }
+
+               /*
+                * In case of sched_debug() we verify the above assumption.
+                */
+               if (!sched_debug())
+                       break;
+       }
+       /*
+        * 'level' contains the number of unique distances, excluding the
+        * identity distance node_distance(i,i).
+        *
+        * The sched_domains_nume_distance[] array includes the actual distance
+        * numbers.
+        */
+
+       /*
+        * Here, we should temporarily reset sched_domains_numa_levels to 0.
+        * If it fails to allocate memory for array sched_domains_numa_masks[][],
+        * the array will contain less then 'level' members. This could be
+        * dangerous when we use it to iterate array sched_domains_numa_masks[][]
+        * in other functions.
+        *
+        * We reset it to 'level' at the end of this function.
+        */
+       sched_domains_numa_levels = 0;
+
+       sched_domains_numa_masks = kzalloc(sizeof(void *) * level, GFP_KERNEL);
+       if (!sched_domains_numa_masks)
+               return;
+
+       /*
+        * Now for each level, construct a mask per node which contains all
+        * cpus of nodes that are that many hops away from us.
+        */
+       for (i = 0; i < level; i++) {
+               sched_domains_numa_masks[i] =
+                       kzalloc(nr_node_ids * sizeof(void *), GFP_KERNEL);
+               if (!sched_domains_numa_masks[i])
+                       return;
+
+               for (j = 0; j < nr_node_ids; j++) {
+                       struct cpumask *mask = kzalloc(cpumask_size(), GFP_KERNEL);
+                       if (!mask)
+                               return;
+
+                       sched_domains_numa_masks[i][j] = mask;
+
+                       for (k = 0; k < nr_node_ids; k++) {
+                               if (node_distance(j, k) > sched_domains_numa_distance[i])
+                                       continue;
+
+                               cpumask_or(mask, mask, cpumask_of_node(k));
+                       }
+               }
+       }
+
+       tl = kzalloc((ARRAY_SIZE(default_topology) + level) *
+                       sizeof(struct sched_domain_topology_level), GFP_KERNEL);
+       if (!tl)
+               return;
+
+       /*
+        * Copy the default topology bits..
+        */
+       for (i = 0; default_topology[i].init; i++)
+               tl[i] = default_topology[i];
+
+       /*
+        * .. and append 'j' levels of NUMA goodness.
+        */
+       for (j = 0; j < level; i++, j++) {
+               tl[i] = (struct sched_domain_topology_level){
+                       .init = sd_numa_init,
+                       .mask = sd_numa_mask,
+                       .flags = SDTL_OVERLAP,
+                       .numa_level = j,
+               };
+       }
+
+       sched_domain_topology = tl;
+
+       sched_domains_numa_levels = level;
+}
+
+static void sched_domains_numa_masks_set(int cpu)
+{
+       int i, j;
+       int node = cpu_to_node(cpu);
+
+       for (i = 0; i < sched_domains_numa_levels; i++) {
+               for (j = 0; j < nr_node_ids; j++) {
+                       if (node_distance(j, node) <= sched_domains_numa_distance[i])
+                               cpumask_set_cpu(cpu, sched_domains_numa_masks[i][j]);
+               }
+       }
+}
+
+static void sched_domains_numa_masks_clear(int cpu)
+{
+       int i, j;
+       for (i = 0; i < sched_domains_numa_levels; i++) {
+               for (j = 0; j < nr_node_ids; j++)
+                       cpumask_clear_cpu(cpu, sched_domains_numa_masks[i][j]);
+       }
+}
+
+/*
+ * Update sched_domains_numa_masks[level][node] array when new cpus
+ * are onlined.
+ */
+static int sched_domains_numa_masks_update(struct notifier_block *nfb,
+                                          unsigned long action,
+                                          void *hcpu)
+{
+       int cpu = (long)hcpu;
+
+       switch (action & ~CPU_TASKS_FROZEN) {
+       case CPU_ONLINE:
+               sched_domains_numa_masks_set(cpu);
+               break;
+
+       case CPU_DEAD:
+               sched_domains_numa_masks_clear(cpu);
+               break;
+
+       default:
+               return NOTIFY_DONE;
+       }
+
+       return NOTIFY_OK;
+}
+#else
+static inline void sched_init_numa(void)
+{
+}
+
+static int sched_domains_numa_masks_update(struct notifier_block *nfb,
+                                          unsigned long action,
+                                          void *hcpu)
+{
+       return 0;
+}
+#endif /* CONFIG_NUMA */
+
+static int __sdt_alloc(const struct cpumask *cpu_map)
+{
+       struct sched_domain_topology_level *tl;
+       int j;
+
+       for (tl = sched_domain_topology; tl->init; tl++) {
+               struct sd_data *sdd = &tl->data;
+
+               sdd->sd = alloc_percpu(struct sched_domain *);
+               if (!sdd->sd)
+                       return -ENOMEM;
+
+               sdd->sg = alloc_percpu(struct sched_group *);
+               if (!sdd->sg)
+                       return -ENOMEM;
+
+               sdd->sgp = alloc_percpu(struct sched_group_power *);
+               if (!sdd->sgp)
+                       return -ENOMEM;
+
+               for_each_cpu(j, cpu_map) {
+                       struct sched_domain *sd;
+                       struct sched_group *sg;
+                       struct sched_group_power *sgp;
+
+                       sd = kzalloc_node(sizeof(struct sched_domain) + cpumask_size(),
+                                       GFP_KERNEL, cpu_to_node(j));
+                       if (!sd)
+                               return -ENOMEM;
+
+                       *per_cpu_ptr(sdd->sd, j) = sd;
+
+                       sg = kzalloc_node(sizeof(struct sched_group) + cpumask_size(),
+                                       GFP_KERNEL, cpu_to_node(j));
+                       if (!sg)
+                               return -ENOMEM;
+
+                       sg->next = sg;
+
+                       *per_cpu_ptr(sdd->sg, j) = sg;
+
+                       sgp = kzalloc_node(sizeof(struct sched_group_power) + cpumask_size(),
+                                       GFP_KERNEL, cpu_to_node(j));
+                       if (!sgp)
+                               return -ENOMEM;
+
+                       *per_cpu_ptr(sdd->sgp, j) = sgp;
+               }
+       }
+
+       return 0;
+}
+
+static void __sdt_free(const struct cpumask *cpu_map)
+{
+       struct sched_domain_topology_level *tl;
+       int j;
+
+       for (tl = sched_domain_topology; tl->init; tl++) {
+               struct sd_data *sdd = &tl->data;
+
+               for_each_cpu(j, cpu_map) {
+                       struct sched_domain *sd;
+
+                       if (sdd->sd) {
+                               sd = *per_cpu_ptr(sdd->sd, j);
+                               if (sd && (sd->flags & SD_OVERLAP))
+                                       free_sched_groups(sd->groups, 0);
+                               kfree(*per_cpu_ptr(sdd->sd, j));
+                       }
+
+                       if (sdd->sg)
+                               kfree(*per_cpu_ptr(sdd->sg, j));
+                       if (sdd->sgp)
+                               kfree(*per_cpu_ptr(sdd->sgp, j));
+               }
+               free_percpu(sdd->sd);
+               sdd->sd = NULL;
+               free_percpu(sdd->sg);
+               sdd->sg = NULL;
+               free_percpu(sdd->sgp);
+               sdd->sgp = NULL;
+       }
+}
+
+struct sched_domain *build_sched_domain(struct sched_domain_topology_level *tl,
+               struct s_data *d, const struct cpumask *cpu_map,
+               struct sched_domain_attr *attr, struct sched_domain *child,
+               int cpu)
+{
+       struct sched_domain *sd = tl->init(tl, cpu);
+       if (!sd)
+               return child;
+
+       cpumask_and(sched_domain_span(sd), cpu_map, tl->mask(cpu));
+       if (child) {
+               sd->level = child->level + 1;
+               sched_domain_level_max = max(sched_domain_level_max, sd->level);
+               child->parent = sd;
+       }
+       sd->child = child;
+       set_domain_attribute(sd, attr);
+
+       return sd;
+}
+
+/*
+ * Build sched domains for a given set of cpus and attach the sched domains
+ * to the individual cpus
+ */
+static int build_sched_domains(const struct cpumask *cpu_map,
+                              struct sched_domain_attr *attr)
+{
+       enum s_alloc alloc_state = sa_none;
+       struct sched_domain *sd;
+       struct s_data d;
+       int i, ret = -ENOMEM;
+
+       alloc_state = __visit_domain_allocation_hell(&d, cpu_map);
+       if (alloc_state != sa_rootdomain)
+               goto error;
+
+       /* Set up domains for cpus specified by the cpu_map. */
+       for_each_cpu(i, cpu_map) {
+               struct sched_domain_topology_level *tl;
+
+               sd = NULL;
+               for (tl = sched_domain_topology; tl->init; tl++) {
+                       sd = build_sched_domain(tl, &d, cpu_map, attr, sd, i);
+                       if (tl->flags & SDTL_OVERLAP || sched_feat(FORCE_SD_OVERLAP))
+                               sd->flags |= SD_OVERLAP;
+                       if (cpumask_equal(cpu_map, sched_domain_span(sd)))
+                               break;
+               }
+
+               while (sd->child)
+                       sd = sd->child;
+
+               *per_cpu_ptr(d.sd, i) = sd;
+       }
+
+       /* Build the groups for the domains */
+       for_each_cpu(i, cpu_map) {
+               for (sd = *per_cpu_ptr(d.sd, i); sd; sd = sd->parent) {
+                       sd->span_weight = cpumask_weight(sched_domain_span(sd));
+                       if (sd->flags & SD_OVERLAP) {
+                               if (build_overlap_sched_groups(sd, i))
+                                       goto error;
+                       } else {
+                               if (build_sched_groups(sd, i))
+                                       goto error;
+                       }
+               }
+       }
+
+       /* Calculate CPU power for physical packages and nodes */
+       for (i = nr_cpumask_bits-1; i >= 0; i--) {
+               if (!cpumask_test_cpu(i, cpu_map))
+                       continue;
+
+               for (sd = *per_cpu_ptr(d.sd, i); sd; sd = sd->parent) {
+                       claim_allocations(i, sd);
+                       init_sched_groups_power(i, sd);
+               }
+       }
+
+       /* Attach the domains */
+       rcu_read_lock();
+       for_each_cpu(i, cpu_map) {
+               sd = *per_cpu_ptr(d.sd, i);
+               cpu_attach_domain(sd, d.rd, i);
+       }
+       rcu_read_unlock();
+
+       ret = 0;
+error:
+       __free_domain_allocs(&d, alloc_state, cpu_map);
+       return ret;
+}
+
+static cpumask_var_t *doms_cur;        /* current sched domains */
+static int ndoms_cur;          /* number of sched domains in 'doms_cur' */
+static struct sched_domain_attr *dattr_cur;
+                               /* attribues of custom domains in 'doms_cur' */
+
+/*
+ * Special case: If a kmalloc of a doms_cur partition (array of
+ * cpumask) fails, then fallback to a single sched domain,
+ * as determined by the single cpumask fallback_doms.
+ */
+static cpumask_var_t fallback_doms;
+
+/*
+ * arch_update_cpu_topology lets virtualized architectures update the
+ * cpu core maps. It is supposed to return 1 if the topology changed
+ * or 0 if it stayed the same.
+ */
+int __attribute__((weak)) arch_update_cpu_topology(void)
+{
+       return 0;
+}
+
+cpumask_var_t *alloc_sched_domains(unsigned int ndoms)
+{
+       int i;
+       cpumask_var_t *doms;
+
+       doms = kmalloc(sizeof(*doms) * ndoms, GFP_KERNEL);
+       if (!doms)
+               return NULL;
+       for (i = 0; i < ndoms; i++) {
+               if (!alloc_cpumask_var(&doms[i], GFP_KERNEL)) {
+                       free_sched_domains(doms, i);
+                       return NULL;
+               }
+       }
+       return doms;
+}
+
+void free_sched_domains(cpumask_var_t doms[], unsigned int ndoms)
+{
+       unsigned int i;
+       for (i = 0; i < ndoms; i++)
+               free_cpumask_var(doms[i]);
+       kfree(doms);
+}
+
+/*
+ * Set up scheduler domains and groups. Callers must hold the hotplug lock.
+ * For now this just excludes isolated cpus, but could be used to
+ * exclude other special cases in the future.
+ */
+static int init_sched_domains(const struct cpumask *cpu_map)
+{
+       int err;
+
+       arch_update_cpu_topology();
+       ndoms_cur = 1;
+       doms_cur = alloc_sched_domains(ndoms_cur);
+       if (!doms_cur)
+               doms_cur = &fallback_doms;
+       cpumask_andnot(doms_cur[0], cpu_map, cpu_isolated_map);
+       err = build_sched_domains(doms_cur[0], NULL);
+       register_sched_domain_sysctl();
+
+       return err;
+}
+
+/*
+ * Detach sched domains from a group of cpus specified in cpu_map
+ * These cpus will now be attached to the NULL domain
+ */
+static void detach_destroy_domains(const struct cpumask *cpu_map)
+{
+       int i;
+
+       rcu_read_lock();
+       for_each_cpu(i, cpu_map)
+               cpu_attach_domain(NULL, &def_root_domain, i);
+       rcu_read_unlock();
+}
+
+/* handle null as "default" */
+static int dattrs_equal(struct sched_domain_attr *cur, int idx_cur,
+                       struct sched_domain_attr *new, int idx_new)
+{
+       struct sched_domain_attr tmp;
+
+       /* fast path */
+       if (!new && !cur)
+               return 1;
+
+       tmp = SD_ATTR_INIT;
+       return !memcmp(cur ? (cur + idx_cur) : &tmp,
+                       new ? (new + idx_new) : &tmp,
+                       sizeof(struct sched_domain_attr));
+}
+
+/*
+ * Partition sched domains as specified by the 'ndoms_new'
+ * cpumasks in the array doms_new[] of cpumasks. This compares
+ * doms_new[] to the current sched domain partitioning, doms_cur[].
+ * It destroys each deleted domain and builds each new domain.
+ *
+ * 'doms_new' is an array of cpumask_var_t's of length 'ndoms_new'.
+ * The masks don't intersect (don't overlap.) We should setup one
+ * sched domain for each mask. CPUs not in any of the cpumasks will
+ * not be load balanced. If the same cpumask appears both in the
+ * current 'doms_cur' domains and in the new 'doms_new', we can leave
+ * it as it is.
+ *
+ * The passed in 'doms_new' should be allocated using
+ * alloc_sched_domains.  This routine takes ownership of it and will
+ * free_sched_domains it when done with it. If the caller failed the
+ * alloc call, then it can pass in doms_new == NULL && ndoms_new == 1,
+ * and partition_sched_domains() will fallback to the single partition
+ * 'fallback_doms', it also forces the domains to be rebuilt.
+ *
+ * If doms_new == NULL it will be replaced with cpu_online_mask.
+ * ndoms_new == 0 is a special case for destroying existing domains,
+ * and it will not create the default domain.
+ *
+ * Call with hotplug lock held
+ */
+void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
+                            struct sched_domain_attr *dattr_new)
+{
+       int i, j, n;
+       int new_topology;
+
+       mutex_lock(&sched_domains_mutex);
+
+       /* always unregister in case we don't destroy any domains */
+       unregister_sched_domain_sysctl();
+
+       /* Let architecture update cpu core mappings. */
+       new_topology = arch_update_cpu_topology();
+
+       n = doms_new ? ndoms_new : 0;
+
+       /* Destroy deleted domains */
+       for (i = 0; i < ndoms_cur; i++) {
+               for (j = 0; j < n && !new_topology; j++) {
+                       if (cpumask_equal(doms_cur[i], doms_new[j])
+                           && dattrs_equal(dattr_cur, i, dattr_new, j))
+                               goto match1;
+               }
+               /* no match - a current sched domain not in new doms_new[] */
+               detach_destroy_domains(doms_cur[i]);
+match1:
+               ;
+       }
+
+       if (doms_new == NULL) {
+               ndoms_cur = 0;
+               doms_new = &fallback_doms;
+               cpumask_andnot(doms_new[0], cpu_active_mask, cpu_isolated_map);
+               WARN_ON_ONCE(dattr_new);
+       }
+
+       /* Build new domains */
+       for (i = 0; i < ndoms_new; i++) {
+               for (j = 0; j < ndoms_cur && !new_topology; j++) {
+                       if (cpumask_equal(doms_new[i], doms_cur[j])
+                           && dattrs_equal(dattr_new, i, dattr_cur, j))
+                               goto match2;
+               }
+               /* no match - add a new doms_new */
+               build_sched_domains(doms_new[i], dattr_new ? dattr_new + i : NULL);
+match2:
+               ;
+       }
+
+       /* Remember the new sched domains */
+       if (doms_cur != &fallback_doms)
+               free_sched_domains(doms_cur, ndoms_cur);
+       kfree(dattr_cur);       /* kfree(NULL) is safe */
+       doms_cur = doms_new;
+       dattr_cur = dattr_new;
+       ndoms_cur = ndoms_new;
+
+       register_sched_domain_sysctl();
+
+       mutex_unlock(&sched_domains_mutex);
+}
+
+static int num_cpus_frozen;    /* used to mark begin/end of suspend/resume */
+
+/*
+ * Update cpusets according to cpu_active mask.  If cpusets are
+ * disabled, cpuset_update_active_cpus() becomes a simple wrapper
+ * around partition_sched_domains().
+ *
+ * If we come here as part of a suspend/resume, don't touch cpusets because we
+ * want to restore it back to its original state upon resume anyway.
+ */
+static int cpuset_cpu_active(struct notifier_block *nfb, unsigned long action,
+                            void *hcpu)
+{
+       switch (action) {
+       case CPU_ONLINE_FROZEN:
+       case CPU_DOWN_FAILED_FROZEN:
+
+               /*
+                * num_cpus_frozen tracks how many CPUs are involved in suspend
+                * resume sequence. As long as this is not the last online
+                * operation in the resume sequence, just build a single sched
+                * domain, ignoring cpusets.
+                */
+               num_cpus_frozen--;
+               if (likely(num_cpus_frozen)) {
+                       partition_sched_domains(1, NULL, NULL);
+                       break;
+               }
+
+               /*
+                * This is the last CPU online operation. So fall through and
+                * restore the original sched domains by considering the
+                * cpuset configurations.
+                */
+
+       case CPU_ONLINE:
+       case CPU_DOWN_FAILED:
+               cpuset_update_active_cpus(true);
+               break;
+       default:
+               return NOTIFY_DONE;
+       }
+       return NOTIFY_OK;
+}
+
+static int cpuset_cpu_inactive(struct notifier_block *nfb, unsigned long action,
+                              void *hcpu)
+{
+       switch (action) {
+       case CPU_DOWN_PREPARE:
+               cpuset_update_active_cpus(false);
+               break;
+       case CPU_DOWN_PREPARE_FROZEN:
+               num_cpus_frozen++;
+               partition_sched_domains(1, NULL, NULL);
+               break;
+       default:
+               return NOTIFY_DONE;
+       }
+       return NOTIFY_OK;
+}
+
+void __init sched_init_smp(void)
+{
+       cpumask_var_t non_isolated_cpus;
+
+       alloc_cpumask_var(&non_isolated_cpus, GFP_KERNEL);
+       alloc_cpumask_var(&fallback_doms, GFP_KERNEL);
+
+       sched_init_numa();
+
+       get_online_cpus();
+       mutex_lock(&sched_domains_mutex);
+       init_sched_domains(cpu_active_mask);
+       cpumask_andnot(non_isolated_cpus, cpu_possible_mask, cpu_isolated_map);
+       if (cpumask_empty(non_isolated_cpus))
+               cpumask_set_cpu(smp_processor_id(), non_isolated_cpus);
+       mutex_unlock(&sched_domains_mutex);
+       put_online_cpus();
+
+       hotcpu_notifier(sched_domains_numa_masks_update, CPU_PRI_SCHED_ACTIVE);
+       hotcpu_notifier(cpuset_cpu_active, CPU_PRI_CPUSET_ACTIVE);
+       hotcpu_notifier(cpuset_cpu_inactive, CPU_PRI_CPUSET_INACTIVE);
+
+       /* RT runtime code needs to handle some hotplug events */
+       hotcpu_notifier(update_runtime, 0);
+
+       init_hrtick();
+
+       /* Move init over to a non-isolated CPU */
+       if (set_cpus_allowed_ptr(current, non_isolated_cpus) < 0)
+               BUG();
+       sched_init_granularity();
+       free_cpumask_var(non_isolated_cpus);
+
+       init_sched_rt_class();
+}
+#else
+void __init sched_init_smp(void)
+{
+       sched_init_granularity();
+}
+#endif /* CONFIG_SMP */
+
+const_debug unsigned int sysctl_timer_migration = 1;
+
+int in_sched_functions(unsigned long addr)
+{
+       return in_lock_functions(addr) ||
+               (addr >= (unsigned long)__sched_text_start
+               && addr < (unsigned long)__sched_text_end);
+}
+
+#ifdef CONFIG_CGROUP_SCHED
+struct task_group root_task_group;
+LIST_HEAD(task_groups);
+#endif
+
+DECLARE_PER_CPU(cpumask_var_t, load_balance_tmpmask);
+
+void __init sched_init(void)
+{
+       int i, j;
+       unsigned long alloc_size = 0, ptr;
+
+#ifdef CONFIG_FAIR_GROUP_SCHED
+       alloc_size += 2 * nr_cpu_ids * sizeof(void **);
+#endif
+#ifdef CONFIG_RT_GROUP_SCHED
+       alloc_size += 2 * nr_cpu_ids * sizeof(void **);
+#endif
+#ifdef CONFIG_CPUMASK_OFFSTACK
+       alloc_size += num_possible_cpus() * cpumask_size();
+#endif
+       if (alloc_size) {
+               ptr = (unsigned long)kzalloc(alloc_size, GFP_NOWAIT);
+
+#ifdef CONFIG_FAIR_GROUP_SCHED
+               root_task_group.se = (struct sched_entity **)ptr;
+               ptr += nr_cpu_ids * sizeof(void **);
+
+               root_task_group.cfs_rq = (struct cfs_rq **)ptr;
+               ptr += nr_cpu_ids * sizeof(void **);
+
+#endif /* CONFIG_FAIR_GROUP_SCHED */
+#ifdef CONFIG_RT_GROUP_SCHED
+               root_task_group.rt_se = (struct sched_rt_entity **)ptr;
+               ptr += nr_cpu_ids * sizeof(void **);
+
+               root_task_group.rt_rq = (struct rt_rq **)ptr;
+               ptr += nr_cpu_ids * sizeof(void **);
+
+#endif /* CONFIG_RT_GROUP_SCHED */
+#ifdef CONFIG_CPUMASK_OFFSTACK
+               for_each_possible_cpu(i) {
+                       per_cpu(load_balance_tmpmask, i) = (void *)ptr;
+                       ptr += cpumask_size();
+               }
+#endif /* CONFIG_CPUMASK_OFFSTACK */
+       }
+
+#ifdef CONFIG_SMP
+       init_defrootdomain();
+#endif
+
+       init_rt_bandwidth(&def_rt_bandwidth,
+                       global_rt_period(), global_rt_runtime());
+
+#ifdef CONFIG_RT_GROUP_SCHED
+       init_rt_bandwidth(&root_task_group.rt_bandwidth,
+                       global_rt_period(), global_rt_runtime());
+#endif /* CONFIG_RT_GROUP_SCHED */
+
+#ifdef CONFIG_CGROUP_SCHED
+       list_add(&root_task_group.list, &task_groups);
+       INIT_LIST_HEAD(&root_task_group.children);
+       INIT_LIST_HEAD(&root_task_group.siblings);
+       autogroup_init(&init_task);
+
+#endif /* CONFIG_CGROUP_SCHED */
+
+#ifdef CONFIG_CGROUP_CPUACCT
+       root_cpuacct.cpustat = &kernel_cpustat;
+       root_cpuacct.cpuusage = alloc_percpu(u64);
+       /* Too early, not expected to fail */
+       BUG_ON(!root_cpuacct.cpuusage);
+#endif
+       for_each_possible_cpu(i) {
+               struct rq *rq;
+
+               rq = cpu_rq(i);
+               raw_spin_lock_init(&rq->lock);
+               rq->nr_running = 0;
+               rq->calc_load_active = 0;
+               rq->calc_load_update = jiffies + LOAD_FREQ;
+               init_cfs_rq(&rq->cfs);
+               init_rt_rq(&rq->rt, rq);
+#ifdef CONFIG_FAIR_GROUP_SCHED
+               root_task_group.shares = ROOT_TASK_GROUP_LOAD;
+               INIT_LIST_HEAD(&rq->leaf_cfs_rq_list);
+               /*
+                * How much cpu bandwidth does root_task_group get?
+                *
+                * In case of task-groups formed thr' the cgroup filesystem, it
+                * gets 100% of the cpu resources in the system. This overall
+                * system cpu resource is divided among the tasks of
+                * root_task_group and its child task-groups in a fair manner,
+                * based on each entity's (task or task-group's) weight
+                * (se->load.weight).
+                *
+                * In other words, if root_task_group has 10 tasks of weight
+                * 1024) and two child groups A0 and A1 (of weight 1024 each),
+                * then A0's share of the cpu resource is:
+                *
+                *      A0's bandwidth = 1024 / (10*1024 + 1024 + 1024) = 8.33%
+                *
+                * We achieve this by letting root_task_group's tasks sit
+                * directly in rq->cfs (i.e root_task_group->se[] = NULL).
+                */
+               init_cfs_bandwidth(&root_task_group.cfs_bandwidth);
+               init_tg_cfs_entry(&root_task_group, &rq->cfs, NULL, i, NULL);
+#endif /* CONFIG_FAIR_GROUP_SCHED */
+
+               rq->rt.rt_runtime = def_rt_bandwidth.rt_runtime;
+#ifdef CONFIG_RT_GROUP_SCHED
+               INIT_LIST_HEAD(&rq->leaf_rt_rq_list);
+               init_tg_rt_entry(&root_task_group, &rq->rt, NULL, i, NULL);
+#endif
+
+               for (j = 0; j < CPU_LOAD_IDX_MAX; j++)
+                       rq->cpu_load[j] = 0;
+
+               rq->last_load_update_tick = jiffies;
+
+#ifdef CONFIG_SMP
+               rq->sd = NULL;
+               rq->rd = NULL;
+               rq->cpu_power = SCHED_POWER_SCALE;
+               rq->post_schedule = 0;
+               rq->active_balance = 0;
+               rq->next_balance = jiffies;
+               rq->push_cpu = 0;
+               rq->cpu = i;
+               rq->online = 0;
+               rq->idle_stamp = 0;
+               rq->avg_idle = 2*sysctl_sched_migration_cost;
+
+               INIT_LIST_HEAD(&rq->cfs_tasks);
+
+               rq_attach_root(rq, &def_root_domain);
+#ifdef CONFIG_NO_HZ
+               rq->nohz_flags = 0;
+#endif
+#endif
+               init_rq_hrtick(rq);
+               atomic_set(&rq->nr_iowait, 0);
+       }
+
+       set_load_weight(&init_task);
+
+#ifdef CONFIG_PREEMPT_NOTIFIERS
+       INIT_HLIST_HEAD(&init_task.preempt_notifiers);
+#endif
+
+#ifdef CONFIG_RT_MUTEXES
+       plist_head_init(&init_task.pi_waiters);
+#endif
+
+       /*
+        * The boot idle thread does lazy MMU switching as well:
+        */
+       atomic_inc(&init_mm.mm_count);
+       enter_lazy_tlb(&init_mm, current);
+
+       /*
+        * Make us the idle thread. Technically, schedule() should not be
+        * called from this thread, however somewhere below it might be,
+        * but because we are the idle thread, we just pick up running again
+        * when this runqueue becomes "idle".
+        */
+       init_idle(current, smp_processor_id());
+
+       calc_load_update = jiffies + LOAD_FREQ;
+
+       /*
+        * During early bootup we pretend to be a normal task:
+        */
+       current->sched_class = &fair_sched_class;
+
+#ifdef CONFIG_SMP
+       zalloc_cpumask_var(&sched_domains_tmpmask, GFP_NOWAIT);
+       /* May be allocated at isolcpus cmdline parse time */
+       if (cpu_isolated_map == NULL)
+               zalloc_cpumask_var(&cpu_isolated_map, GFP_NOWAIT);
+       idle_thread_set_boot_cpu();
+#endif
+       init_sched_fair_class();
+
+       scheduler_running = 1;
+}
+
+#ifdef CONFIG_DEBUG_ATOMIC_SLEEP
+static inline int preempt_count_equals(int preempt_offset)
+{
+       int nested = (preempt_count() & ~PREEMPT_ACTIVE) + rcu_preempt_depth();
+
+       return (nested == preempt_offset);
+}
+
+void __might_sleep(const char *file, int line, int preempt_offset)
+{
+       static unsigned long prev_jiffy;        /* ratelimiting */
+
+       rcu_sleep_check(); /* WARN_ON_ONCE() by default, no rate limit reqd. */
+       if ((preempt_count_equals(preempt_offset) && !irqs_disabled()) ||
+           system_state != SYSTEM_RUNNING || oops_in_progress)
+               return;
+       if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy)
+               return;
+       prev_jiffy = jiffies;
+
+       printk(KERN_ERR
+               "BUG: sleeping function called from invalid context at %s:%d\n",
+                       file, line);
+       printk(KERN_ERR
+               "in_atomic(): %d, irqs_disabled(): %d, pid: %d, name: %s\n",
+                       in_atomic(), irqs_disabled(),
+                       current->pid, current->comm);
+
+       debug_show_held_locks(current);
+       if (irqs_disabled())
+               print_irqtrace_events(current);
+       dump_stack();
+}
+EXPORT_SYMBOL(__might_sleep);
+#endif
+
+#ifdef CONFIG_MAGIC_SYSRQ
+static void normalize_task(struct rq *rq, struct task_struct *p)
+{
+       const struct sched_class *prev_class = p->sched_class;
+       int old_prio = p->prio;
+       int on_rq;
+
+       on_rq = p->on_rq;
+       if (on_rq)
+               dequeue_task(rq, p, 0);
+       __setscheduler(rq, p, SCHED_NORMAL, 0);
+       if (on_rq) {
+               enqueue_task(rq, p, 0);
+               resched_task(rq->curr);
+       }
+
+       check_class_changed(rq, p, prev_class, old_prio);
+}
+
+void normalize_rt_tasks(void)
+{
+       struct task_struct *g, *p;
+       unsigned long flags;
+       struct rq *rq;
+
+       read_lock_irqsave(&tasklist_lock, flags);
+       do_each_thread(g, p) {
+               /*
+                * Only normalize user tasks:
+                */
+               if (!p->mm)
+                       continue;
+
+               p->se.exec_start                = 0;
+#ifdef CONFIG_SCHEDSTATS
+               p->se.statistics.wait_start     = 0;
+               p->se.statistics.sleep_start    = 0;
+               p->se.statistics.block_start    = 0;
+#endif
+
+               if (!rt_task(p)) {
+                       /*
+                        * Renice negative nice level userspace
+                        * tasks back to 0:
+                        */
+                       if (TASK_NICE(p) < 0 && p->mm)
+                               set_user_nice(p, 0);
+                       continue;
+               }
+
+               raw_spin_lock(&p->pi_lock);
+               rq = __task_rq_lock(p);
+
+               normalize_task(rq, p);
+
+               __task_rq_unlock(rq);
+               raw_spin_unlock(&p->pi_lock);
+       } while_each_thread(g, p);
+
+       read_unlock_irqrestore(&tasklist_lock, flags);
+}
+
+#endif /* CONFIG_MAGIC_SYSRQ */
+
+#if defined(CONFIG_IA64) || defined(CONFIG_KGDB_KDB)
+/*
+ * These functions are only useful for the IA64 MCA handling, or kdb.
+ *
+ * They can only be called when the whole system has been
+ * stopped - every CPU needs to be quiescent, and no scheduling
+ * activity can take place. Using them for anything else would
+ * be a serious bug, and as a result, they aren't even visible
+ * under any other configuration.
+ */
+
+/**
+ * curr_task - return the current task for a given cpu.
+ * @cpu: the processor in question.
+ *
+ * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED!
+ */
+struct task_struct *curr_task(int cpu)
+{
+       return cpu_curr(cpu);
+}
+
+#endif /* defined(CONFIG_IA64) || defined(CONFIG_KGDB_KDB) */
+
+#ifdef CONFIG_IA64
+/**
+ * set_curr_task - set the current task for a given cpu.
+ * @cpu: the processor in question.
+ * @p: the task pointer to set.
+ *
+ * Description: This function must only be used when non-maskable interrupts
+ * are serviced on a separate stack. It allows the architecture to switch the
+ * notion of the current task on a cpu in a non-blocking manner. This function
+ * must be called with all CPU's synchronized, and interrupts disabled, the
+ * and caller must save the original value of the current task (see
+ * curr_task() above) and restore that value before reenabling interrupts and
+ * re-starting the system.
+ *
+ * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED!
+ */
+void set_curr_task(int cpu, struct task_struct *p)
+{
+       cpu_curr(cpu) = p;
+}
+
+#endif
+
+#ifdef CONFIG_CGROUP_SCHED
+/* task_group_lock serializes the addition/removal of task groups */
+static DEFINE_SPINLOCK(task_group_lock);
+
+static void free_sched_group(struct task_group *tg)
+{
+       free_fair_sched_group(tg);
+       free_rt_sched_group(tg);
+       autogroup_free(tg);
+       kfree(tg);
+}
+
+/* allocate runqueue etc for a new task group */
+struct task_group *sched_create_group(struct task_group *parent)
+{
+       struct task_group *tg;
+
+       tg = kzalloc(sizeof(*tg), GFP_KERNEL);
+       if (!tg)
+               return ERR_PTR(-ENOMEM);
+
+       if (!alloc_fair_sched_group(tg, parent))
+               goto err;
+
+       if (!alloc_rt_sched_group(tg, parent))
+               goto err;
+
+       return tg;
+
+err:
+       free_sched_group(tg);
+       return ERR_PTR(-ENOMEM);
+}
+
+void sched_online_group(struct task_group *tg, struct task_group *parent)
+{
+       unsigned long flags;
+
+       spin_lock_irqsave(&task_group_lock, flags);
+       list_add_rcu(&tg->list, &task_groups);
+
+       WARN_ON(!parent); /* root should already exist */
+
+       tg->parent = parent;
+       INIT_LIST_HEAD(&tg->children);
+       list_add_rcu(&tg->siblings, &parent->children);
+       spin_unlock_irqrestore(&task_group_lock, flags);
+}
+
+/* rcu callback to free various structures associated with a task group */
+static void free_sched_group_rcu(struct rcu_head *rhp)
+{
+       /* now it should be safe to free those cfs_rqs */
+       free_sched_group(container_of(rhp, struct task_group, rcu));
+}
+
+/* Destroy runqueue etc associated with a task group */
+void sched_destroy_group(struct task_group *tg)
+{
+       /* wait for possible concurrent references to cfs_rqs complete */
+       call_rcu(&tg->rcu, free_sched_group_rcu);
+}
+
+void sched_offline_group(struct task_group *tg)
+{
+       unsigned long flags;
+       int i;
+
+       /* end participation in shares distribution */
+       for_each_possible_cpu(i)
+               unregister_fair_sched_group(tg, i);
+
+       spin_lock_irqsave(&task_group_lock, flags);
+       list_del_rcu(&tg->list);
+       list_del_rcu(&tg->siblings);
+       spin_unlock_irqrestore(&task_group_lock, flags);
+}
+
+/* change task's runqueue when it moves between groups.
+ *     The caller of this function should have put the task in its new group
+ *     by now. This function just updates tsk->se.cfs_rq and tsk->se.parent to
+ *     reflect its new group.
+ */
+void sched_move_task(struct task_struct *tsk)
+{
+       struct task_group *tg;
+       int on_rq, running;
+       unsigned long flags;
+       struct rq *rq;
+
+       rq = task_rq_lock(tsk, &flags);
+
+       running = task_current(rq, tsk);
+       on_rq = tsk->on_rq;
+
+       if (on_rq)
+               dequeue_task(rq, tsk, 0);
+       if (unlikely(running))
+               tsk->sched_class->put_prev_task(rq, tsk);
+
+       tg = container_of(task_subsys_state_check(tsk, cpu_cgroup_subsys_id,
+                               lockdep_is_held(&tsk->sighand->siglock)),
+                         struct task_group, css);
+       tg = autogroup_task_group(tsk, tg);
+       tsk->sched_task_group = tg;
+
+#ifdef CONFIG_FAIR_GROUP_SCHED
+       if (tsk->sched_class->task_move_group)
+               tsk->sched_class->task_move_group(tsk, on_rq);
+       else
+#endif
+               set_task_rq(tsk, task_cpu(tsk));
+
+       if (unlikely(running))
+               tsk->sched_class->set_curr_task(rq);
+       if (on_rq)
+               enqueue_task(rq, tsk, 0);
+
+       task_rq_unlock(rq, tsk, &flags);
+}
+#endif /* CONFIG_CGROUP_SCHED */
+
+#if defined(CONFIG_RT_GROUP_SCHED) || defined(CONFIG_CFS_BANDWIDTH)
+static unsigned long to_ratio(u64 period, u64 runtime)
+{
+       if (runtime == RUNTIME_INF)
+               return 1ULL << 20;
+
+       return div64_u64(runtime << 20, period);
+}
+#endif
+
+#ifdef CONFIG_RT_GROUP_SCHED
+/*
+ * Ensure that the real time constraints are schedulable.
+ */
+static DEFINE_MUTEX(rt_constraints_mutex);
+
+/* Must be called with tasklist_lock held */
+static inline int tg_has_rt_tasks(struct task_group *tg)
+{
+       struct task_struct *g, *p;
+
+       do_each_thread(g, p) {
+               if (rt_task(p) && task_rq(p)->rt.tg == tg)
+                       return 1;
+       } while_each_thread(g, p);
+
+       return 0;
+}
+
+struct rt_schedulable_data {
+       struct task_group *tg;
+       u64 rt_period;
+       u64 rt_runtime;
+};
+
+static int tg_rt_schedulable(struct task_group *tg, void *data)
+{
+       struct rt_schedulable_data *d = data;
+       struct task_group *child;
+       unsigned long total, sum = 0;
+       u64 period, runtime;
+
+       period = ktime_to_ns(tg->rt_bandwidth.rt_period);
+       runtime = tg->rt_bandwidth.rt_runtime;
+
+       if (tg == d->tg) {
+               period = d->rt_period;
+               runtime = d->rt_runtime;
+       }
+
+       /*
+        * Cannot have more runtime than the period.
+        */
+       if (runtime > period && runtime != RUNTIME_INF)
+               return -EINVAL;
+
+       /*
+        * Ensure we don't starve existing RT tasks.
+        */
+       if (rt_bandwidth_enabled() && !runtime && tg_has_rt_tasks(tg))
+               return -EBUSY;
+
+       total = to_ratio(period, runtime);
+
+       /*
+        * Nobody can have more than the global setting allows.
+        */
+       if (total > to_ratio(global_rt_period(), global_rt_runtime()))
+               return -EINVAL;
+
+       /*
+        * The sum of our children's runtime should not exceed our own.
+        */
+       list_for_each_entry_rcu(child, &tg->children, siblings) {
+               period = ktime_to_ns(child->rt_bandwidth.rt_period);
+               runtime = child->rt_bandwidth.rt_runtime;
+
+               if (child == d->tg) {
+                       period = d->rt_period;
+                       runtime = d->rt_runtime;
+               }
+
+               sum += to_ratio(period, runtime);
+       }
+
+       if (sum > total)
+               return -EINVAL;
+
+       return 0;
+}
+
+static int __rt_schedulable(struct task_group *tg, u64 period, u64 runtime)
+{
+       int ret;
+
+       struct rt_schedulable_data data = {
+               .tg = tg,
+               .rt_period = period,
+               .rt_runtime = runtime,
+       };
+
+       rcu_read_lock();
+       ret = walk_tg_tree(tg_rt_schedulable, tg_nop, &data);
+       rcu_read_unlock();
+
+       return ret;
+}
+
+static int tg_set_rt_bandwidth(struct task_group *tg,
+               u64 rt_period, u64 rt_runtime)
+{
+       int i, err = 0;
+
+       mutex_lock(&rt_constraints_mutex);
+       read_lock(&tasklist_lock);
+       err = __rt_schedulable(tg, rt_period, rt_runtime);
+       if (err)
+               goto unlock;
+
+       raw_spin_lock_irq(&tg->rt_bandwidth.rt_runtime_lock);
+       tg->rt_bandwidth.rt_period = ns_to_ktime(rt_period);
+       tg->rt_bandwidth.rt_runtime = rt_runtime;
+
+       for_each_possible_cpu(i) {
+               struct rt_rq *rt_rq = tg->rt_rq[i];
+
+               raw_spin_lock(&rt_rq->rt_runtime_lock);
+               rt_rq->rt_runtime = rt_runtime;
+               raw_spin_unlock(&rt_rq->rt_runtime_lock);
+       }
+       raw_spin_unlock_irq(&tg->rt_bandwidth.rt_runtime_lock);
+unlock:
+       read_unlock(&tasklist_lock);
+       mutex_unlock(&rt_constraints_mutex);
+
+       return err;
+}
+
+int sched_group_set_rt_runtime(struct task_group *tg, long rt_runtime_us)
+{
+       u64 rt_runtime, rt_period;
+
+       rt_period = ktime_to_ns(tg->rt_bandwidth.rt_period);
+       rt_runtime = (u64)rt_runtime_us * NSEC_PER_USEC;
+       if (rt_runtime_us < 0)
+               rt_runtime = RUNTIME_INF;
+
+       return tg_set_rt_bandwidth(tg, rt_period, rt_runtime);
+}
+
+long sched_group_rt_runtime(struct task_group *tg)
+{
+       u64 rt_runtime_us;
+
+       if (tg->rt_bandwidth.rt_runtime == RUNTIME_INF)
+               return -1;
+
+       rt_runtime_us = tg->rt_bandwidth.rt_runtime;
+       do_div(rt_runtime_us, NSEC_PER_USEC);
+       return rt_runtime_us;
+}
+
+int sched_group_set_rt_period(struct task_group *tg, long rt_period_us)
+{
+       u64 rt_runtime, rt_period;
+
+       rt_period = (u64)rt_period_us * NSEC_PER_USEC;
+       rt_runtime = tg->rt_bandwidth.rt_runtime;
+
+       if (rt_period == 0)
+               return -EINVAL;
+
+       return tg_set_rt_bandwidth(tg, rt_period, rt_runtime);
+}
+
+long sched_group_rt_period(struct task_group *tg)
+{
+       u64 rt_period_us;
+
+       rt_period_us = ktime_to_ns(tg->rt_bandwidth.rt_period);
+       do_div(rt_period_us, NSEC_PER_USEC);
+       return rt_period_us;
+}
+
+static int sched_rt_global_constraints(void)
+{
+       u64 runtime, period;
+       int ret = 0;
+
+       if (sysctl_sched_rt_period <= 0)
+               return -EINVAL;
+
+       runtime = global_rt_runtime();
+       period = global_rt_period();
+
+       /*
+        * Sanity check on the sysctl variables.
+        */
+       if (runtime > period && runtime != RUNTIME_INF)
+               return -EINVAL;
+
+       mutex_lock(&rt_constraints_mutex);
+       read_lock(&tasklist_lock);
+       ret = __rt_schedulable(NULL, 0, 0);
+       read_unlock(&tasklist_lock);
+       mutex_unlock(&rt_constraints_mutex);
+
+       return ret;
+}
+
+int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk)
+{
+       /* Don't accept realtime tasks when there is no way for them to run */
+       if (rt_task(tsk) && tg->rt_bandwidth.rt_runtime == 0)
+               return 0;
+
+       return 1;
+}
+
+#else /* !CONFIG_RT_GROUP_SCHED */
+static int sched_rt_global_constraints(void)
+{
+       unsigned long flags;
+       int i;
+
+       if (sysctl_sched_rt_period <= 0)
+               return -EINVAL;
+
+       /*
+        * There's always some RT tasks in the root group
+        * -- migration, kstopmachine etc..
+        */
+       if (sysctl_sched_rt_runtime == 0)
+               return -EBUSY;
+
+       raw_spin_lock_irqsave(&def_rt_bandwidth.rt_runtime_lock, flags);
+       for_each_possible_cpu(i) {
+               struct rt_rq *rt_rq = &cpu_rq(i)->rt;
+
+               raw_spin_lock(&rt_rq->rt_runtime_lock);
+               rt_rq->rt_runtime = global_rt_runtime();
+               raw_spin_unlock(&rt_rq->rt_runtime_lock);
+       }
+       raw_spin_unlock_irqrestore(&def_rt_bandwidth.rt_runtime_lock, flags);
+
+       return 0;
+}
+#endif /* CONFIG_RT_GROUP_SCHED */
+
+int sched_rr_handler(struct ctl_table *table, int write,
+               void __user *buffer, size_t *lenp,
+               loff_t *ppos)
+{
+       int ret;
+       static DEFINE_MUTEX(mutex);
+
+       mutex_lock(&mutex);
+       ret = proc_dointvec(table, write, buffer, lenp, ppos);
+       /* make sure that internally we keep jiffies */
+       /* also, writing zero resets timeslice to default */
+       if (!ret && write) {
+               sched_rr_timeslice = sched_rr_timeslice <= 0 ?
+                       RR_TIMESLICE : msecs_to_jiffies(sched_rr_timeslice);
+       }
+       mutex_unlock(&mutex);
+       return ret;
+}
+
+int sched_rt_handler(struct ctl_table *table, int write,
+               void __user *buffer, size_t *lenp,
+               loff_t *ppos)
+{
+       int ret;
+       int old_period, old_runtime;
+       static DEFINE_MUTEX(mutex);
+
+       mutex_lock(&mutex);
+       old_period = sysctl_sched_rt_period;
+       old_runtime = sysctl_sched_rt_runtime;
+
+       ret = proc_dointvec(table, write, buffer, lenp, ppos);
+
+       if (!ret && write) {
+               ret = sched_rt_global_constraints();
+               if (ret) {
+                       sysctl_sched_rt_period = old_period;
+                       sysctl_sched_rt_runtime = old_runtime;
+               } else {
+                       def_rt_bandwidth.rt_runtime = global_rt_runtime();
+                       def_rt_bandwidth.rt_period =
+                               ns_to_ktime(global_rt_period());
+               }
+       }
+       mutex_unlock(&mutex);
+
+       return ret;
+}
+
+#ifdef CONFIG_CGROUP_SCHED
+
+/* return corresponding task_group object of a cgroup */
+static inline struct task_group *cgroup_tg(struct cgroup *cgrp)
+{
+       return container_of(cgroup_subsys_state(cgrp, cpu_cgroup_subsys_id),
+                           struct task_group, css);
+}
+
+static struct cgroup_subsys_state *cpu_cgroup_css_alloc(struct cgroup *cgrp)
+{
+       struct task_group *tg, *parent;
+
+       if (!cgrp->parent) {
+               /* This is early initialization for the top cgroup */
+               return &root_task_group.css;
+       }
+
+       parent = cgroup_tg(cgrp->parent);
+       tg = sched_create_group(parent);
+       if (IS_ERR(tg))
+               return ERR_PTR(-ENOMEM);
+
+       return &tg->css;
+}
+
+static int cpu_cgroup_css_online(struct cgroup *cgrp)
+{
+       struct task_group *tg = cgroup_tg(cgrp);
+       struct task_group *parent;
+
+       if (!cgrp->parent)
+               return 0;
+
+       parent = cgroup_tg(cgrp->parent);
+       sched_online_group(tg, parent);
+       return 0;
+}
+
+static void cpu_cgroup_css_free(struct cgroup *cgrp)
+{
+       struct task_group *tg = cgroup_tg(cgrp);
+
+       sched_destroy_group(tg);
+}
+
+static void cpu_cgroup_css_offline(struct cgroup *cgrp)
+{
+       struct task_group *tg = cgroup_tg(cgrp);
+
+       sched_offline_group(tg);
+}
+
+static int cpu_cgroup_can_attach(struct cgroup *cgrp,
+                                struct cgroup_taskset *tset)
+{
+       struct task_struct *task;
+
+       cgroup_taskset_for_each(task, cgrp, tset) {
+#ifdef CONFIG_RT_GROUP_SCHED
+               if (!sched_rt_can_attach(cgroup_tg(cgrp), task))
+                       return -EINVAL;
+#else
+               /* We don't support RT-tasks being in separate groups */
+               if (task->sched_class != &fair_sched_class)
+                       return -EINVAL;
+#endif
+       }
+       return 0;
+}
+
+static void cpu_cgroup_attach(struct cgroup *cgrp,
+                             struct cgroup_taskset *tset)
+{
+       struct task_struct *task;
+
+       cgroup_taskset_for_each(task, cgrp, tset)
+               sched_move_task(task);
+}
+
+static void
+cpu_cgroup_exit(struct cgroup *cgrp, struct cgroup *old_cgrp,
+               struct task_struct *task)
+{
+       /*
+        * cgroup_exit() is called in the copy_process() failure path.
+        * Ignore this case since the task hasn't ran yet, this avoids
+        * trying to poke a half freed task state from generic code.
+        */
+       if (!(task->flags & PF_EXITING))
+               return;
+
+       sched_move_task(task);
+}
+
+#ifdef CONFIG_FAIR_GROUP_SCHED
+static int cpu_shares_write_u64(struct cgroup *cgrp, struct cftype *cftype,
+                               u64 shareval)
+{
+       return sched_group_set_shares(cgroup_tg(cgrp), scale_load(shareval));
+}
+
+static u64 cpu_shares_read_u64(struct cgroup *cgrp, struct cftype *cft)
+{
+       struct task_group *tg = cgroup_tg(cgrp);
+
+       return (u64) scale_load_down(tg->shares);
+}
+
+#ifdef CONFIG_CFS_BANDWIDTH
+static DEFINE_MUTEX(cfs_constraints_mutex);
+
+const u64 max_cfs_quota_period = 1 * NSEC_PER_SEC; /* 1s */
+const u64 min_cfs_quota_period = 1 * NSEC_PER_MSEC; /* 1ms */
+
+static int __cfs_schedulable(struct task_group *tg, u64 period, u64 runtime);
+
+static int tg_set_cfs_bandwidth(struct task_group *tg, u64 period, u64 quota)
+{
+       int i, ret = 0, runtime_enabled, runtime_was_enabled;
+       struct cfs_bandwidth *cfs_b = &tg->cfs_bandwidth;
+
+       if (tg == &root_task_group)
+               return -EINVAL;
+
+       /*
+        * Ensure we have at some amount of bandwidth every period.  This is
+        * to prevent reaching a state of large arrears when throttled via
+        * entity_tick() resulting in prolonged exit starvation.
+        */
+       if (quota < min_cfs_quota_period || period < min_cfs_quota_period)
+               return -EINVAL;
+
+       /*
+        * Likewise, bound things on the otherside by preventing insane quota
+        * periods.  This also allows us to normalize in computing quota
+        * feasibility.
+        */
+       if (period > max_cfs_quota_period)
+               return -EINVAL;
+
+       mutex_lock(&cfs_constraints_mutex);
+       ret = __cfs_schedulable(tg, period, quota);
+       if (ret)
+               goto out_unlock;
+
+       runtime_enabled = quota != RUNTIME_INF;
+       runtime_was_enabled = cfs_b->quota != RUNTIME_INF;
+       account_cfs_bandwidth_used(runtime_enabled, runtime_was_enabled);
+       raw_spin_lock_irq(&cfs_b->lock);
+       cfs_b->period = ns_to_ktime(period);
+       cfs_b->quota = quota;
+
+       __refill_cfs_bandwidth_runtime(cfs_b);
+       /* restart the period timer (if active) to handle new period expiry */
+       if (runtime_enabled && cfs_b->timer_active) {
+               /* force a reprogram */
+               cfs_b->timer_active = 0;
+               __start_cfs_bandwidth(cfs_b);
+       }
+       raw_spin_unlock_irq(&cfs_b->lock);
+
+       for_each_possible_cpu(i) {
+               struct cfs_rq *cfs_rq = tg->cfs_rq[i];
+               struct rq *rq = cfs_rq->rq;
+
+               raw_spin_lock_irq(&rq->lock);
+               cfs_rq->runtime_enabled = runtime_enabled;
+               cfs_rq->runtime_remaining = 0;
+
+               if (cfs_rq->throttled)
+                       unthrottle_cfs_rq(cfs_rq);
+               raw_spin_unlock_irq(&rq->lock);
+       }
+out_unlock:
+       mutex_unlock(&cfs_constraints_mutex);
+
+       return ret;
+}
+
+int tg_set_cfs_quota(struct task_group *tg, long cfs_quota_us)
+{
+       u64 quota, period;
+
+       period = ktime_to_ns(tg->cfs_bandwidth.period);
+       if (cfs_quota_us < 0)
+               quota = RUNTIME_INF;
+       else
+               quota = (u64)cfs_quota_us * NSEC_PER_USEC;
+
+       return tg_set_cfs_bandwidth(tg, period, quota);
+}
+
+long tg_get_cfs_quota(struct task_group *tg)
+{
+       u64 quota_us;
+
+       if (tg->cfs_bandwidth.quota == RUNTIME_INF)
+               return -1;
+
+       quota_us = tg->cfs_bandwidth.quota;
+       do_div(quota_us, NSEC_PER_USEC);
+
+       return quota_us;
+}
+
+int tg_set_cfs_period(struct task_group *tg, long cfs_period_us)
+{
+       u64 quota, period;
+
+       period = (u64)cfs_period_us * NSEC_PER_USEC;
+       quota = tg->cfs_bandwidth.quota;
+
+       return tg_set_cfs_bandwidth(tg, period, quota);
+}
+
+long tg_get_cfs_period(struct task_group *tg)
+{
+       u64 cfs_period_us;
+
+       cfs_period_us = ktime_to_ns(tg->cfs_bandwidth.period);
+       do_div(cfs_period_us, NSEC_PER_USEC);
+
+       return cfs_period_us;
+}
+
+static s64 cpu_cfs_quota_read_s64(struct cgroup *cgrp, struct cftype *cft)
+{
+       return tg_get_cfs_quota(cgroup_tg(cgrp));
+}
+
+static int cpu_cfs_quota_write_s64(struct cgroup *cgrp, struct cftype *cftype,
+                               s64 cfs_quota_us)
+{
+       return tg_set_cfs_quota(cgroup_tg(cgrp), cfs_quota_us);
+}
+
+static u64 cpu_cfs_period_read_u64(struct cgroup *cgrp, struct cftype *cft)
+{
+       return tg_get_cfs_period(cgroup_tg(cgrp));
+}
+
+static int cpu_cfs_period_write_u64(struct cgroup *cgrp, struct cftype *cftype,
+                               u64 cfs_period_us)
+{
+       return tg_set_cfs_period(cgroup_tg(cgrp), cfs_period_us);
+}
+
+struct cfs_schedulable_data {
+       struct task_group *tg;
+       u64 period, quota;
+};
+
+/*
+ * normalize group quota/period to be quota/max_period
+ * note: units are usecs
+ */
+static u64 normalize_cfs_quota(struct task_group *tg,
+                              struct cfs_schedulable_data *d)
+{
+       u64 quota, period;
+
+       if (tg == d->tg) {
+               period = d->period;
+               quota = d->quota;
+       } else {
+               period = tg_get_cfs_period(tg);
+               quota = tg_get_cfs_quota(tg);
+       }
+
+       /* note: these should typically be equivalent */
+       if (quota == RUNTIME_INF || quota == -1)
+               return RUNTIME_INF;
+
+       return to_ratio(period, quota);
+}
+
+static int tg_cfs_schedulable_down(struct task_group *tg, void *data)
+{
+       struct cfs_schedulable_data *d = data;
+       struct cfs_bandwidth *cfs_b = &tg->cfs_bandwidth;
+       s64 quota = 0, parent_quota = -1;
+
+       if (!tg->parent) {
+               quota = RUNTIME_INF;
+       } else {
+               struct cfs_bandwidth *parent_b = &tg->parent->cfs_bandwidth;
+
+               quota = normalize_cfs_quota(tg, d);
+               parent_quota = parent_b->hierarchal_quota;
+
+               /*
+                * ensure max(child_quota) <= parent_quota, inherit when no
+                * limit is set
+                */
+               if (quota == RUNTIME_INF)
+                       quota = parent_quota;
+               else if (parent_quota != RUNTIME_INF && quota > parent_quota)
+                       return -EINVAL;
+       }
+       cfs_b->hierarchal_quota = quota;
+
+       return 0;
+}
+
+static int __cfs_schedulable(struct task_group *tg, u64 period, u64 quota)
+{
+       int ret;
+       struct cfs_schedulable_data data = {
+               .tg = tg,
+               .period = period,
+               .quota = quota,
+       };
+
+       if (quota != RUNTIME_INF) {
+               do_div(data.period, NSEC_PER_USEC);
+               do_div(data.quota, NSEC_PER_USEC);
+       }
+
+       rcu_read_lock();
+       ret = walk_tg_tree(tg_cfs_schedulable_down, tg_nop, &data);
+       rcu_read_unlock();
+
+       return ret;
+}
+
+static int cpu_stats_show(struct cgroup *cgrp, struct cftype *cft,
+               struct cgroup_map_cb *cb)
+{
+       struct task_group *tg = cgroup_tg(cgrp);
+       struct cfs_bandwidth *cfs_b = &tg->cfs_bandwidth;
+
+       cb->fill(cb, "nr_periods", cfs_b->nr_periods);
+       cb->fill(cb, "nr_throttled", cfs_b->nr_throttled);
+       cb->fill(cb, "throttled_time", cfs_b->throttled_time);
+
+       return 0;
+}
+#endif /* CONFIG_CFS_BANDWIDTH */
+#endif /* CONFIG_FAIR_GROUP_SCHED */
+
+#ifdef CONFIG_RT_GROUP_SCHED
+static int cpu_rt_runtime_write(struct cgroup *cgrp, struct cftype *cft,
+                               s64 val)
+{
+       return sched_group_set_rt_runtime(cgroup_tg(cgrp), val);
+}
+
+static s64 cpu_rt_runtime_read(struct cgroup *cgrp, struct cftype *cft)
+{
+       return sched_group_rt_runtime(cgroup_tg(cgrp));
+}
+
+static int cpu_rt_period_write_uint(struct cgroup *cgrp, struct cftype *cftype,
+               u64 rt_period_us)
+{
+       return sched_group_set_rt_period(cgroup_tg(cgrp), rt_period_us);
+}
+
+static u64 cpu_rt_period_read_uint(struct cgroup *cgrp, struct cftype *cft)
+{
+       return sched_group_rt_period(cgroup_tg(cgrp));
+}
+#endif /* CONFIG_RT_GROUP_SCHED */
+
+static struct cftype cpu_files[] = {
+#ifdef CONFIG_FAIR_GROUP_SCHED
+       {
+               .name = "shares",
+               .read_u64 = cpu_shares_read_u64,
+               .write_u64 = cpu_shares_write_u64,
+       },
+#endif
+#ifdef CONFIG_CFS_BANDWIDTH
+       {
+               .name = "cfs_quota_us",
+               .read_s64 = cpu_cfs_quota_read_s64,
+               .write_s64 = cpu_cfs_quota_write_s64,
+       },
+       {
+               .name = "cfs_period_us",
+               .read_u64 = cpu_cfs_period_read_u64,
+               .write_u64 = cpu_cfs_period_write_u64,
+       },
+       {
+               .name = "stat",
+               .read_map = cpu_stats_show,
+       },
+#endif
+#ifdef CONFIG_RT_GROUP_SCHED
+       {
+               .name = "rt_runtime_us",
+               .read_s64 = cpu_rt_runtime_read,
+               .write_s64 = cpu_rt_runtime_write,
+       },
+       {
+               .name = "rt_period_us",
+               .read_u64 = cpu_rt_period_read_uint,
+               .write_u64 = cpu_rt_period_write_uint,
+       },