add bfs to linux 2.6.31

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@17699 3c298f89-4303-0410-b956-a3cf2f4a3e73

1 files changed, 6448 insertions, 0 deletions

diff --git a/target/linux/generic-2.6/patches-2.6.31/270-sched_bfs.patch b/target/linux/generic-2.6/patches-2.6.31/270-sched_bfs.patch
new file mode 100644
index 0000000000..1f805dfe5f
--- /dev/null
+++ b/target/linux/generic-2.6/patches-2.6.31/270-sched_bfs.patch
@@ -0,0 +1,6448 @@
+This patch adds support for bfs v230, modified for diff size reduction
+
+--- a/Documentation/sysctl/kernel.txt
++++ b/Documentation/sysctl/kernel.txt
+@@ -27,6 +27,7 @@ show up in /proc/sys/kernel:
+ - domainname
+ - hostname
+ - hotplug
++- iso_cpu
+ - java-appletviewer           [ binfmt_java, obsolete ]
+ - java-interpreter            [ binfmt_java, obsolete ]
+ - kstack_depth_to_print       [ X86 only ]
+@@ -49,6 +50,7 @@ show up in /proc/sys/kernel:
+ - randomize_va_space
+ - real-root-dev               ==> Documentation/initrd.txt
+ - reboot-cmd                  [ SPARC only ]
++- rr_interval
+ - rtsig-max
+ - rtsig-nr
+ - sem
+@@ -171,6 +173,16 @@ Default value is "/sbin/hotplug".
+ 
+ ==============================================================
+ 
++iso_cpu: (BFS only)
++
++This sets the percentage cpu that the unprivileged SCHED_ISO tasks can
++run effectively at realtime priority, averaged over a rolling five
++seconds over the -whole- system, meaning all cpus.
++
++Set to 70 (percent) by default.
++
++==============================================================
++
+ l2cr: (PPC only)
+ 
+ This flag controls the L2 cache of G3 processor boards. If
+@@ -333,6 +345,19 @@ rebooting. ???
+ 
+ ==============================================================
+ 
++rr_interval: (BFS only)
++
++This is the smallest duration that any cpu process scheduling unit
++will run for. Increasing this value can increase throughput of cpu
++bound tasks substantially but at the expense of increased latencies
++overall. This value is in milliseconds and the default value chosen
++depends on the number of cpus available at scheduler initialisation
++with a minimum of 6.
++
++Valid values are from 1-5000.
++
++==============================================================
++
+ rtsig-max & rtsig-nr:
+ 
+ The file rtsig-max can be used to tune the maximum number
+--- a/include/linux/init_task.h
++++ b/include/linux/init_task.h
+@@ -116,9 +116,10 @@ extern struct cred init_cred;
+ 	.usage		= ATOMIC_INIT(2),				\
+ 	.flags		= PF_KTHREAD,					\
+ 	.lock_depth	= -1,						\
+-	.prio		= MAX_PRIO-20,					\
++	.prio		= NORMAL_PRIO,					\
+ 	.static_prio	= MAX_PRIO-20,					\
+-	.normal_prio	= MAX_PRIO-20,					\
++	.normal_prio	= NORMAL_PRIO,					\
++	.deadline	= 0,						\
+ 	.policy		= SCHED_NORMAL,					\
+ 	.cpus_allowed	= CPU_MASK_ALL,					\
+ 	.mm		= NULL,						\
+--- a/include/linux/sched.h
++++ b/include/linux/sched.h
+@@ -36,9 +36,12 @@
+ #define SCHED_FIFO		1
+ #define SCHED_RR		2
+ #define SCHED_BATCH		3
+-/* SCHED_ISO: reserved but not implemented yet */
++#define SCHED_ISO		4
+ #define SCHED_IDLE		5
+ 
++#define SCHED_MAX		(SCHED_IDLE)
++#define SCHED_RANGE(policy)	((policy) <= SCHED_MAX)
++
+ #ifdef __KERNEL__
+ 
+ struct sched_param {
+@@ -1090,10 +1093,13 @@ struct sched_entity {
+ 	struct load_weight	load;		/* for load-balancing */
+ 	struct rb_node		run_node;
+ 	struct list_head	group_node;
++#ifdef CONFIG_SCHED_CFS
+ 	unsigned int		on_rq;
+ 
+ 	u64			exec_start;
++#endif
+ 	u64			sum_exec_runtime;
++#ifdef CONFIG_SCHED_CFS
+ 	u64			vruntime;
+ 	u64			prev_sum_exec_runtime;
+ 
+@@ -1145,6 +1151,7 @@ struct sched_entity {
+ 	/* rq "owned" by this entity/group: */
+ 	struct cfs_rq		*my_q;
+ #endif
++#endif
+ };
+ 
+ struct sched_rt_entity {
+@@ -1172,17 +1179,19 @@ struct task_struct {
+ 
+ 	int lock_depth;		/* BKL lock depth */
+ 
+-#ifdef CONFIG_SMP
+-#ifdef __ARCH_WANT_UNLOCKED_CTXSW
+ 	int oncpu;
+-#endif
+-#endif
+-
+ 	int prio, static_prio, normal_prio;
+ 	unsigned int rt_priority;
+ 	const struct sched_class *sched_class;
+ 	struct sched_entity se;
+ 	struct sched_rt_entity rt;
++	unsigned long deadline;
++#ifdef CONFIG_SCHED_BFS
++	int load_weight;	/* for niceness load balancing purposes */
++	int first_time_slice;
++	unsigned long long timestamp, last_ran;
++	unsigned long utime_pc, stime_pc;
++#endif
+ 
+ #ifdef CONFIG_PREEMPT_NOTIFIERS
+ 	/* list of struct preempt_notifier: */
+@@ -1205,6 +1214,9 @@ struct task_struct {
+ 
+ 	unsigned int policy;
+ 	cpumask_t cpus_allowed;
++#ifdef CONFIG_HOTPLUG_CPU
++	cpumask_t unplugged_mask;
++#endif
+ 
+ #ifdef CONFIG_PREEMPT_RCU
+ 	int rcu_read_lock_nesting;
+@@ -1497,11 +1509,19 @@ struct task_struct {
+  * priority to a value higher than any user task. Note:
+  * MAX_RT_PRIO must not be smaller than MAX_USER_RT_PRIO.
+  */
+-
++#define PRIO_RANGE		(40)
+ #define MAX_USER_RT_PRIO	100
+ #define MAX_RT_PRIO		MAX_USER_RT_PRIO
+-
++#ifdef CONFIG_SCHED_BFS
++#define MAX_PRIO		(MAX_RT_PRIO + PRIO_RANGE)
++#define ISO_PRIO		(MAX_RT_PRIO)
++#define NORMAL_PRIO		(MAX_RT_PRIO + 1)
++#define IDLE_PRIO		(MAX_RT_PRIO + 2)
++#define PRIO_LIMIT		((IDLE_PRIO) + 1)
++#else
+ #define MAX_PRIO		(MAX_RT_PRIO + 40)
++#define NORMAL_PRIO	(MAX_RT_PRIO - 20)
++#endif
+ #define DEFAULT_PRIO		(MAX_RT_PRIO + 20)
+ 
+ static inline int rt_prio(int prio)
+@@ -1785,7 +1805,7 @@ task_sched_runtime(struct task_struct *t
+ extern unsigned long long thread_group_sched_runtime(struct task_struct *task);
+ 
+ /* sched_exec is called by processes performing an exec */
+-#ifdef CONFIG_SMP
++#if defined(CONFIG_SMP) && defined(CONFIG_SCHED_CFS)
+ extern void sched_exec(void);
+ #else
+ #define sched_exec()   {}
+--- a/init/Kconfig
++++ b/init/Kconfig
+@@ -441,9 +441,22 @@ config LOG_BUF_SHIFT
+ config HAVE_UNSTABLE_SCHED_CLOCK
+ 	bool
+ 
++choice
++	prompt "Scheduler"
++	default SCHED_CFS
++
++	config SCHED_CFS
++		bool "CFS"
++
++	config SCHED_BFS
++		bool "BFS"
++
++endchoice
++
+ config GROUP_SCHED
+ 	bool "Group CPU scheduler"
+ 	depends on EXPERIMENTAL
++	depends on SCHED_CFS
+ 	default n
+ 	help
+ 	  This feature lets CPU scheduler recognize task groups and control CPU
+@@ -494,6 +507,7 @@ endchoice
+ 
+ menuconfig CGROUPS
+ 	boolean "Control Group support"
++	depends on SCHED_CFS
+ 	help
+ 	  This option adds support for grouping sets of processes together, for
+ 	  use with process control subsystems such as Cpusets, CFS, memory
+--- a/kernel/Makefile
++++ b/kernel/Makefile
+@@ -2,7 +2,7 @@
+ # Makefile for the linux kernel.
+ #
+ 
+-obj-y     = sched.o fork.o exec_domain.o panic.o printk.o \
++obj-y     = $(if $(CONFIG_SCHED_CFS),sched.o,sched_bfs.o) fork.o exec_domain.o panic.o printk.o \
+ 	    cpu.o exit.o itimer.o time.o softirq.o resource.o \
+ 	    sysctl.o capability.o ptrace.o timer.o user.o \
+ 	    signal.o sys.o kmod.o workqueue.o pid.o \
+@@ -108,6 +108,7 @@ ifneq ($(CONFIG_SCHED_OMIT_FRAME_POINTER
+ # 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_sched.o := $(PROFILING) -fno-omit-frame-pointer
++CFLAGS_sched_bfs.o := $(PROFILING) -fno-omit-frame-pointer
+ endif
+ 
+ $(obj)/configs.o: $(obj)/config_data.h
+--- a/kernel/kthread.c
++++ b/kernel/kthread.c
+@@ -16,7 +16,11 @@
+ #include <linux/mutex.h>
+ #include <trace/events/sched.h>
+ 
++#ifdef CONFIG_SCHED_BFS
++#define KTHREAD_NICE_LEVEL (0)
++#else
+ #define KTHREAD_NICE_LEVEL (-5)
++#endif
+ 
+ static DEFINE_SPINLOCK(kthread_create_lock);
+ static LIST_HEAD(kthread_create_list);
+--- /dev/null
++++ b/kernel/sched_bfs.c
+@@ -0,0 +1,6105 @@
++/*
++ *  kernel/sched_bfs.c, was sched.c
++ *
++ *  Kernel scheduler and related syscalls
++ *
++ *  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
++ *  now		Brainfuck deadline scheduling policy by Con Kolivas deletes
++ *              a whole lot of those previous things.
++ */
++
++#include <linux/mm.h>
++#include <linux/module.h>
++#include <linux/nmi.h>
++#include <linux/init.h>
++#include <asm/uaccess.h>
++#include <linux/highmem.h>
++#include <linux/smp_lock.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_counter.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/smp.h>
++#include <linux/threads.h>
++#include <linux/timer.h>
++#include <linux/rcupdate.h>
++#include <linux/cpu.h>
++#include <linux/cpuset.h>
++#include <linux/cpumask.h>
++#include <linux/percpu.h>
++#include <linux/kthread.h>
++#include <linux/proc_fs.h>
++#include <linux/seq_file.h>
++#include <linux/syscalls.h>
++#include <linux/times.h>
++#include <linux/tsacct_kern.h>
++#include <linux/kprobes.h>
++#include <linux/delayacct.h>
++#include <linux/reciprocal_div.h>
++#include <linux/log2.h>
++#include <linux/bootmem.h>
++#include <linux/ftrace.h>
++
++#include <asm/tlb.h>
++#include <asm/unistd.h>
++
++#define CREATE_TRACE_POINTS
++#include <trace/events/sched.h>
++
++#define rt_prio(prio)		unlikely((prio) < MAX_RT_PRIO)
++#define rt_task(p)		rt_prio((p)->prio)
++#define rt_queue(rq)		rt_prio((rq)->rq_prio)
++#define batch_task(p)		(unlikely((p)->policy == SCHED_BATCH))
++#define is_rt_policy(policy)	((policy) == SCHED_FIFO || \
++					(policy) == SCHED_RR)
++#define has_rt_policy(p)	unlikely(is_rt_policy((p)->policy))
++#define idleprio_task(p)	unlikely((p)->policy == SCHED_IDLE)
++#define iso_task(p)		unlikely((p)->policy == SCHED_ISO)
++#define iso_queue(rq)		unlikely((rq)->rq_policy == SCHED_ISO)
++#define ISO_PERIOD		((5 * HZ * num_online_cpus()) + 1)
++
++/*
++ * Convert user-nice values [ -20 ... 0 ... 19 ]
++ * to static priority [ MAX_RT_PRIO..MAX_PRIO-1 ],
++ * and back.
++ */
++#define NICE_TO_PRIO(nice)	(MAX_RT_PRIO + (nice) + 20)
++#define PRIO_TO_NICE(prio)	((prio) - MAX_RT_PRIO - 20)
++#define TASK_NICE(p)		PRIO_TO_NICE((p)->static_prio)
++
++/*
++ * 'User priority' is the nice value converted to something we
++ * can work with better when scaling various scheduler parameters,
++ * it's a [ 0 ... 39 ] range.
++ */
++#define USER_PRIO(p)		((p)-MAX_RT_PRIO)
++#define TASK_USER_PRIO(p)	USER_PRIO((p)->static_prio)
++#define MAX_USER_PRIO		(USER_PRIO(MAX_PRIO))
++#define SCHED_PRIO(p)		((p)+MAX_RT_PRIO)
++
++/* Some helpers for converting to/from various scales.*/
++#define JIFFIES_TO_NS(TIME)	((TIME) * (1000000000 / HZ))
++#define MS_TO_NS(TIME)		((TIME) * 1000000)
++#define MS_TO_US(TIME)		((TIME) * 1000)
++
++#ifdef CONFIG_SMP
++/*
++ * Divide a load by a sched group cpu_power : (load / sg->__cpu_power)
++ * Since cpu_power is a 'constant', we can use a reciprocal divide.
++ */
++static inline u32 sg_div_cpu_power(const struct sched_group *sg, u32 load)
++{
++	return reciprocal_divide(load, sg->reciprocal_cpu_power);
++}
++
++/*
++ * Each time a sched group cpu_power is changed,
++ * we must compute its reciprocal value
++ */
++static inline void sg_inc_cpu_power(struct sched_group *sg, u32 val)
++{
++	sg->__cpu_power += val;
++	sg->reciprocal_cpu_power = reciprocal_value(sg->__cpu_power);
++}
++#endif
++
++/*
++ * This is the time all tasks within the same priority round robin.
++ * Value is in ms and set to a minimum of 6ms. Scales with number of cpus.
++ * Tunable via /proc interface.
++ */
++int rr_interval __read_mostly = 6;
++
++/*
++ * sched_iso_cpu - sysctl which determines the cpu percentage SCHED_ISO tasks
++ * are allowed to run five seconds as real time tasks. This is the total over
++ * all online cpus.
++ */
++int sched_iso_cpu __read_mostly = 70;
++
++int prio_ratios[PRIO_RANGE] __read_mostly;
++
++static inline unsigned long timeslice(void)
++{
++	return MS_TO_US(rr_interval);
++}
++
++struct global_rq {
++	spinlock_t lock;
++	unsigned long nr_running;
++	unsigned long nr_uninterruptible;
++	unsigned long long nr_switches;
++	struct list_head queue[PRIO_LIMIT];
++	DECLARE_BITMAP(prio_bitmap, PRIO_LIMIT + 1);
++	unsigned long iso_ticks;
++	unsigned short iso_refractory;
++#ifdef CONFIG_SMP
++	unsigned long qnr; /* queued not running */
++	cpumask_t cpu_idle_map;
++#endif
++};
++
++static struct global_rq grq;
++
++/*
++ * This is the main, per-CPU runqueue data structure.
++ * All this is protected by the global_rq lock.
++ */
++struct rq {
++#ifdef CONFIG_SMP
++#ifdef CONFIG_NO_HZ
++	unsigned char in_nohz_recently;
++#endif
++#endif
++
++	struct task_struct *curr, *idle;
++	struct mm_struct *prev_mm;
++	struct list_head queue; /* Place to store currently running task */
++
++	/* Stored data about rq->curr to work outside grq lock */
++	unsigned long rq_deadline;
++	unsigned int rq_policy;
++	int rq_time_slice;
++	int rq_prio;
++
++	/* Accurate timekeeping data */
++	u64 timekeep_clock;
++	unsigned long user_pc, nice_pc, irq_pc, softirq_pc, system_pc,
++			iowait_pc, idle_pc;
++	atomic_t nr_iowait;
++
++	int cpu;		/* cpu of this runqueue */
++	int online;
++
++#ifdef CONFIG_SMP
++	struct root_domain *rd;
++	struct sched_domain *sd;
++
++	struct list_head migration_queue;
++#endif
++
++	u64 clock;
++#ifdef CONFIG_SCHEDSTATS
++
++	/* latency stats */
++	struct sched_info rq_sched_info;
++	unsigned long long rq_cpu_time;
++	/* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */
++
++	/* sys_sched_yield() stats */
++	unsigned int yld_count;
++
++	/* schedule() stats */
++	unsigned int sched_switch;
++	unsigned int sched_count;
++	unsigned int sched_goidle;
++
++	/* try_to_wake_up() stats */
++	unsigned int ttwu_count;
++	unsigned int ttwu_local;
++
++	/* BKL stats */
++	unsigned int bkl_count;
++#endif
++};
++
++static DEFINE_PER_CPU(struct rq, runqueues) ____cacheline_aligned_in_smp;
++static DEFINE_MUTEX(sched_hotcpu_mutex);
++
++#ifdef CONFIG_SMP
++
++/*
++ * We add the notion of a root-domain which will be used to define per-domain
++ * variables. Each exclusive cpuset essentially defines an island domain by
++ * fully partitioning the member cpus from any other cpuset. Whenever a new
++ * exclusive cpuset is created, we also create and attach a new root-domain
++ * object.
++ *
++ */
++struct root_domain {
++	atomic_t refcount;
++	cpumask_var_t span;
++	cpumask_var_t online;
++
++	/*
++	 * The "RT overload" flag: it gets set if a CPU has more than
++	 * one runnable RT task.
++	 */
++	cpumask_var_t rto_mask;
++	atomic_t rto_count;
++#if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT)
++	/*
++	 * Preferred wake up cpu nominated by sched_mc balance that will be
++	 * used when most cpus are idle in the system indicating overall very
++	 * low system utilisation. Triggered at POWERSAVINGS_BALANCE_WAKEUP(2)
++	 */
++	unsigned int sched_mc_preferred_wakeup_cpu;
++#endif
++};
++
++/*
++ * By default the system creates a single root-domain with all cpus as
++ * members (mimicking the global state we have today).
++ */
++static struct root_domain def_root_domain;
++
++#endif
++
++static inline int cpu_of(struct rq *rq)
++{
++#ifdef CONFIG_SMP
++	return rq->cpu;
++#else
++	return 0;
++#endif
++}
++
++/*
++ * The domain tree (rq->sd) is protected by RCU's quiescent state transition.
++ * See detach_destroy_domains: synchronize_sched for details.
++ *
++ * The domain tree of any CPU may only be accessed from within
++ * preempt-disabled sections.
++ */
++#define for_each_domain(cpu, __sd) \
++	for (__sd = rcu_dereference(cpu_rq(cpu)->sd); __sd; __sd = __sd->parent)
++
++#define cpu_rq(cpu)		(&per_cpu(runqueues, (cpu)))
++#define this_rq()		(&__get_cpu_var(runqueues))
++#define task_rq(p)		cpu_rq(task_cpu(p))
++#define cpu_curr(cpu)		(cpu_rq(cpu)->curr)
++
++#include "sched_stats.h"
++
++#ifndef prepare_arch_switch
++# define prepare_arch_switch(next)	do { } while (0)
++#endif
++#ifndef finish_arch_switch
++# define finish_arch_switch(prev)	do { } while (0)
++#endif
++
++inline void update_rq_clock(struct rq *rq)
++{
++	rq->clock = sched_clock_cpu(cpu_of(rq));
++}
++
++static inline int task_running(struct task_struct *p)
++{
++	return (!!p->oncpu);
++}
++
++static inline void grq_lock(void)
++	__acquires(grq.lock)
++{
++	smp_mb();
++	spin_lock(&grq.lock);
++}
++
++static inline void grq_unlock(void)
++	__releases(grq.lock)
++{
++	spin_unlock(&grq.lock);
++}
++
++static inline void grq_lock_irq(void)
++	__acquires(grq.lock)
++{
++	smp_mb();
++	spin_lock_irq(&grq.lock);
++}
++
++static inline void time_lock_grq(struct rq *rq)
++	__acquires(grq.lock)
++{
++	grq_lock();
++	update_rq_clock(rq);
++}
++
++static inline void grq_unlock_irq(void)
++	__releases(grq.lock)
++{
++	spin_unlock_irq(&grq.lock);
++}
++
++static inline void grq_lock_irqsave(unsigned long *flags)
++	__acquires(grq.lock)
++{
++	smp_mb();
++	spin_lock_irqsave(&grq.lock, *flags);
++}
++
++static inline void grq_unlock_irqrestore(unsigned long *flags)
++	__releases(grq.lock)
++{
++	spin_unlock_irqrestore(&grq.lock, *flags);
++}
++
++static inline struct rq
++*task_grq_lock(struct task_struct *p, unsigned long *flags)
++	__acquires(grq.lock)
++{
++	grq_lock_irqsave(flags);
++	return task_rq(p);
++}
++
++static inline struct rq
++*time_task_grq_lock(struct task_struct *p, unsigned long *flags)
++	__acquires(grq.lock)
++{
++	struct rq *rq = task_grq_lock(p, flags);
++	update_rq_clock(rq);
++	return rq;
++}
++
++static inline void task_grq_unlock(unsigned long *flags)
++	__releases(grq.lock)
++{
++	grq_unlock_irqrestore(flags);
++}
++
++/**
++ * runqueue_is_locked
++ *
++ * Returns true if the global runqueue is locked.
++ * This interface allows printk to be called with the runqueue lock
++ * held and know whether or not it is OK to wake up the klogd.
++ */
++int runqueue_is_locked(void)
++{
++	return spin_is_locked(&grq.lock);
++}
++
++void task_rq_unlock_wait(struct task_struct *p)
++	__releases(grq.lock)
++{
++	smp_mb(); /* spin-unlock-wait is not a full memory barrier */
++	spin_unlock_wait(&grq.lock);
++}
++
++static inline void time_grq_lock(struct rq *rq, unsigned long *flags)
++	__acquires(grq.lock)
++{
++	spin_lock_irqsave(&grq.lock, *flags);
++	update_rq_clock(rq);
++}
++
++static inline struct rq *__task_grq_lock(struct task_struct *p)
++	__acquires(grq.lock)
++{
++	grq_lock();
++	return task_rq(p);
++}
++
++static inline void __task_grq_unlock(void)
++	__releases(grq.lock)
++{
++	grq_unlock();
++}
++
++#ifndef __ARCH_WANT_UNLOCKED_CTXSW
++static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next)
++{
++}
++
++static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev)
++{
++#ifdef CONFIG_DEBUG_SPINLOCK
++	/* this is a valid case when another task releases the spinlock */
++	grq.lock.owner = current;
++#endif
++	/*
++	 * If we are tracking spinlock dependencies then we have to
++	 * fix up the runqueue lock - which gets 'carried over' from
++	 * prev into current:
++	 */
++	spin_acquire(&grq.lock.dep_map, 0, 0, _THIS_IP_);
++
++	grq_unlock_irq();
++}
++
++#else /* __ARCH_WANT_UNLOCKED_CTXSW */
++
++static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next)
++{
++#ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
++	grq_unlock_irq();
++#else
++	grq_unlock();
++#endif
++}
++
++static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev)
++{
++	smp_wmb();
++#ifndef __ARCH_WANT_INTERRUPTS_ON_CTXSW
++	local_irq_enable();
++#endif
++}
++#endif /* __ARCH_WANT_UNLOCKED_CTXSW */
++
++/*
++ * A task that is queued will be on the grq run list.
++ * A task that is not running or queued will not be on the grq run list.
++ * A task that is currently running will have ->oncpu set and be queued
++ * temporarily in its own rq queue.
++ * A task that is running and no longer queued will be seen only on
++ * context switch exit.
++ */
++
++static inline int task_queued(struct task_struct *p)
++{
++	return (!list_empty(&p->rt.run_list));
++}
++
++static inline int task_queued_only(struct task_struct *p)
++{
++	return (!list_empty(&p->rt.run_list) && !task_running(p));
++}
++
++/*
++ * Removing from the global runqueue. Enter with grq locked.
++ */
++static void dequeue_task(struct task_struct *p)
++{
++	list_del_init(&p->rt.run_list);
++	if (list_empty(grq.queue + p->prio))
++		__clear_bit(p->prio, grq.prio_bitmap);
++}
++
++static inline void reset_first_time_slice(struct task_struct *p)
++{
++	if (unlikely(p->first_time_slice))
++		p->first_time_slice = 0;
++}
++
++static int idleprio_suitable(struct task_struct *p)
++{
++	return (!freezing(p) && !signal_pending(p) &&
++		!(task_contributes_to_load(p)) && !(p->flags & (PF_EXITING)));
++}
++
++static int isoprio_suitable(void)
++{
++	return !grq.iso_refractory;
++}
++
++/*
++ * Adding to the global runqueue. Enter with grq locked.
++ */
++static void enqueue_task(struct task_struct *p)
++{
++	if (!rt_task(p)) {
++		/* Check it hasn't gotten rt from PI */
++		if ((idleprio_task(p) && idleprio_suitable(p)) ||
++		   (iso_task(p) && isoprio_suitable()))
++			p->prio = p->normal_prio;
++		else
++			p->prio = NORMAL_PRIO;
++	}
++	__set_bit(p->prio, grq.prio_bitmap);
++	list_add_tail(&p->rt.run_list, grq.queue + p->prio);
++	sched_info_queued(p);
++}
++
++/* Only idle task does this as a real time task*/
++static inline void enqueue_task_head(struct task_struct *p)
++{
++	__set_bit(p->prio, grq.prio_bitmap);
++	list_add(&p->rt.run_list, grq.queue + p->prio);
++	sched_info_queued(p);
++}
++
++static inline void requeue_task(struct task_struct *p)
++{
++	sched_info_queued(p);
++}
++
++static inline int pratio(struct task_struct *p)
++{
++	return prio_ratios[TASK_USER_PRIO(p)];
++}
++
++/*
++ * task_timeslice - all tasks of all priorities get the exact same timeslice
++ * length. CPU distribution is handled by giving different deadlines to
++ * tasks of different priorities.
++ */
++static inline int task_timeslice(struct task_struct *p)
++{
++	return (rr_interval * pratio(p) / 100);
++}
++
++#ifdef CONFIG_SMP
++static inline void inc_qnr(void)
++{
++	grq.qnr++;
++}
++
++static inline void dec_qnr(void)
++{
++	grq.qnr--;
++}
++
++static inline int queued_notrunning(void)
++{
++	return grq.qnr;
++}
++#else
++static inline void inc_qnr(void)
++{
++}
++
++static inline void dec_qnr(void)
++{
++}
++
++static inline int queued_notrunning(void)
++{
++	return grq.nr_running;
++}
++#endif
++
++/*
++ * activate_idle_task - move idle task to the _front_ of runqueue.
++ */
++static inline void activate_idle_task(struct task_struct *p)
++{
++	enqueue_task_head(p);
++	grq.nr_running++;
++	inc_qnr();
++}
++
++static inline int normal_prio(struct task_struct *p)
++{
++	if (has_rt_policy(p))
++		return MAX_RT_PRIO - 1 - p->rt_priority;
++	if (idleprio_task(p))
++		return IDLE_PRIO;
++	if (iso_task(p))
++		return ISO_PRIO;
++	return NORMAL_PRIO;
++}
++
++/*
++ * Calculate the current priority, i.e. the priority
++ * taken into account by the scheduler. This value might
++ * be boosted by RT tasks as it will be RT if the task got
++ * RT-boosted. If not then it returns p->normal_prio.
++ */
++static int effective_prio(struct task_struct *p)
++{
++	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;
++}
++
++/*
++ * activate_task - move a task to the runqueue. Enter with grq locked. The rq
++ * doesn't really matter but gives us the local clock.
++ */
++static void activate_task(struct task_struct *p, struct rq *rq)
++{
++	u64 now = rq->clock;
++
++	/*
++	 * Sleep time is in units of nanosecs, so shift by 20 to get a
++	 * milliseconds-range estimation of the amount of time that the task
++	 * spent sleeping:
++	 */
++	if (unlikely(prof_on == SLEEP_PROFILING)) {
++		if (p->state == TASK_UNINTERRUPTIBLE)
++			profile_hits(SLEEP_PROFILING, (void *)get_wchan(p),
++				     (now - p->timestamp) >> 20);
++	}
++
++	p->prio = effective_prio(p);
++	p->timestamp = now;
++	if (task_contributes_to_load(p))
++		grq.nr_uninterruptible--;
++	enqueue_task(p);
++	grq.nr_running++;
++	inc_qnr();
++}
++
++/*
++ * deactivate_task - If it's running, it's not on the grq and we can just
++ * decrement the nr_running.
++ */
++static inline void deactivate_task(struct task_struct *p)
++{
++	if (task_contributes_to_load(p))
++		grq.nr_uninterruptible++;
++	grq.nr_running--;
++}
++
++#ifdef CONFIG_SMP
++void set_task_cpu(struct task_struct *p, unsigned int cpu)
++{
++	trace_sched_migrate_task(p, cpu);
++	/*
++	 * After ->cpu is set up to a new value, task_grq_lock(p, ...) can be
++	 * successfuly executed on another CPU. We must ensure that updates of
++	 * per-task data have been completed by this moment.
++	 */
++	smp_wmb();
++	task_thread_info(p)->cpu = cpu;
++}
++#endif
++
++/*
++ * Move a task off the global queue and take it to a cpu for it will
++ * become the running task.
++ */
++static inline void take_task(struct rq *rq, struct task_struct *p)
++{
++	set_task_cpu(p, rq->cpu);
++	dequeue_task(p);
++	list_add(&p->rt.run_list, &rq->queue);
++	dec_qnr();
++}
++
++/*
++ * Returns a descheduling task to the grq runqueue unless it is being
++ * deactivated.
++ */
++static inline void return_task(struct task_struct *p, int deactivate)
++{
++	list_del_init(&p->rt.run_list);
++	if (deactivate)
++		deactivate_task(p);
++	else {
++		inc_qnr();
++		enqueue_task(p);
++	}
++}
++
++/*
++ * resched_task - mark a task 'to be rescheduled now'.
++ *
++ * 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.
++ */
++#ifdef CONFIG_SMP
++
++#ifndef tsk_is_polling
++#define tsk_is_polling(t) test_tsk_thread_flag(t, TIF_POLLING_NRFLAG)
++#endif
++
++static void resched_task(struct task_struct *p)
++{
++	int cpu;
++
++	assert_spin_locked(&grq.lock);
++
++	if (unlikely(test_tsk_thread_flag(p, TIF_NEED_RESCHED)))
++		return;
++
++	set_tsk_thread_flag(p, TIF_NEED_RESCHED);
++
++	cpu = task_cpu(p);
++	if (cpu == smp_processor_id())
++		return;
++
++	/* NEED_RESCHED must be visible before we test polling */
++	smp_mb();
++	if (!tsk_is_polling(p))
++		smp_send_reschedule(cpu);
++}
++
++#else
++static inline void resched_task(struct task_struct *p)
++{
++	assert_spin_locked(&grq.lock);
++	set_tsk_need_resched(p);
++}
++#endif
++
++/**
++ * 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 cpu_curr(task_cpu(p)) == p;
++}
++
++#ifdef CONFIG_SMP
++struct migration_req {
++	struct list_head list;
++
++	struct task_struct *task;
++	int dest_cpu;
++
++	struct completion done;
++};
++
++/*
++ * wait_task_context_switch -	wait for a thread to complete at least one
++ *				context switch.
++ *
++ * @p must not be current.
++ */
++void wait_task_context_switch(struct task_struct *p)
++{
++	unsigned long nvcsw, nivcsw, flags;
++	int running;
++	struct rq *rq;
++
++	nvcsw	= p->nvcsw;
++	nivcsw	= p->nivcsw;
++	for (;;) {
++		/*
++		 * The runqueue is assigned before the actual context
++		 * switch. We need to take the runqueue lock.
++		 *
++		 * We could check initially without the lock but it is
++		 * very likely that we need to take the lock in every
++		 * iteration.
++		 */
++		rq = task_grq_lock(p, &flags);
++		running = task_running(p);
++		task_grq_unlock(&flags);
++
++		if (likely(!running))
++			break;
++		/*
++		 * The switch count is incremented before the actual
++		 * context switch. We thus wait for two switches to be
++		 * sure at least one completed.
++		 */
++		if ((p->nvcsw - nvcsw) > 1)
++			break;
++		if ((p->nivcsw - nivcsw) > 1)
++			break;
++
++		cpu_relax();
++	}
++}
++
++/*
++ * wait_task_inactive - wait for a thread to unschedule.
++ *
++ * 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.
++ *
++ * 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.
++ */
++unsigned long wait_task_inactive(struct task_struct *p, long match_state)
++{
++	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 this will
++		 * return false if the runqueue has changed and p
++		 * is actually now running somewhere else!
++		 */
++		while (task_running(p) && p == rq->curr) {
++			if (match_state && unlikely(p->state != match_state))
++				return 0;
++			cpu_relax();
++		}
++
++		/*
++		 * Ok, time to look more closely! We need the grq
++		 * lock now, to be *sure*. If we're wrong, we'll
++		 * just go back and repeat.
++		 */
++		rq = task_grq_lock(p, &flags);
++		trace_sched_wait_task(rq, p);
++		running = task_running(p);
++		on_rq = task_queued(p);
++		ncsw = 0;
++		if (!match_state || p->state == match_state)
++			ncsw = p->nvcsw | LONG_MIN; /* sets MSB */
++		task_grq_unlock(&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)) {
++			schedule_timeout_uninterruptible(1);
++			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;
++}
++
++/***
++ * kick_process - kick a running thread to enter/exit the kernel
++ * @p: the to-be-kicked thread
++ *
++ * Cause a process which is running on another CPU to enter
++ * kernel-mode, without any delay. (to get signals handled.)
++ *
++ * NOTE: this function doesnt 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.
++ */
++void kick_process(struct task_struct *p)
++{
++	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
++
++#define rq_idle(rq)	((rq)->rq_prio == PRIO_LIMIT)
++
++/*
++ * RT tasks preempt purely on priority. SCHED_NORMAL tasks preempt on the
++ * basis of earlier deadlines. SCHED_BATCH and SCHED_IDLE don't preempt,
++ * they cooperatively multitask.
++ */
++static inline int task_preempts_curr(struct task_struct *p, struct rq *rq)
++{
++	int preempts = 0;
++
++	if (p->prio < rq->rq_prio)
++		preempts = 1;
++	else if (p->policy == SCHED_NORMAL && (p->prio == rq->rq_prio &&
++		 time_before(p->deadline, rq->rq_deadline)))
++			preempts = 1;
++	return preempts;
++}
++
++/*
++ * Wake up *any* suitable cpu to schedule this task.
++ */
++static void try_preempt(struct task_struct *p)
++{
++	struct rq *highest_prio_rq, *this_rq;
++	unsigned long latest_deadline, cpu;
++	int highest_prio;
++	cpumask_t tmp;
++
++	/* Try the task's previous rq first and as a fallback */
++	this_rq = task_rq(p);
++
++	if (cpu_isset(this_rq->cpu, p->cpus_allowed)) {
++		highest_prio_rq = this_rq;
++		/* If this_rq is idle, use that. */
++		if (rq_idle(this_rq))
++			goto found_rq;
++	} else
++		highest_prio_rq = cpu_rq(any_online_cpu(p->cpus_allowed));
++	latest_deadline = this_rq->rq_deadline;
++	highest_prio = this_rq->rq_prio;
++
++	cpus_and(tmp, cpu_online_map, p->cpus_allowed);
++
++	for_each_cpu_mask(cpu, tmp) {
++		struct rq *rq;
++		int rq_prio;
++
++		rq = cpu_rq(cpu);
++
++		if (rq_idle(rq)) {
++			/* found an idle rq, use that one */
++			highest_prio_rq = rq;
++			goto found_rq;
++		}
++
++		rq_prio = rq->rq_prio;
++		if (rq_prio > highest_prio ||
++			(rq_prio == highest_prio &&
++			time_after(rq->rq_deadline, latest_deadline))) {
++				highest_prio = rq_prio;
++				latest_deadline = rq->rq_deadline;
++				highest_prio_rq = rq;
++		}
++	}
++
++	if (!task_preempts_curr(p, highest_prio_rq))
++		return;
++found_rq:
++	resched_task(highest_prio_rq->curr);
++	return;
++}
++
++/**
++ * task_oncpu_function_call - call a function on the cpu on which a task runs
++ * @p:		the task to evaluate
++ * @func:	the function to be called
++ * @info:	the function call argument
++ *
++ * Calls the function @func when the task is currently running. This might
++ * be on the current CPU, which just calls the function directly
++ */
++void task_oncpu_function_call(struct task_struct *p,
++			      void (*func) (void *info), void *info)
++{
++	int cpu;
++
++	preempt_disable();
++	cpu = task_cpu(p);
++	if (task_curr(p))
++		smp_call_function_single(cpu, func, info, 1);
++	preempt_enable();
++}
++
++#ifdef CONFIG_SMP
++static int suitable_idle_cpus(struct task_struct *p)
++{
++	return (cpus_intersects(p->cpus_allowed, grq.cpu_idle_map));
++}
++#else
++static int suitable_idle_cpus(struct task_struct *p)
++{
++	return 0;
++}
++#endif
++
++/***
++ * try_to_wake_up - wake up a thread
++ * @p: the to-be-woken-up thread
++ * @state: the mask of task states that can be woken
++ * @sync: do a synchronous wakeup?
++ *
++ * 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 failure only if the task is already active.
++ */
++static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync)
++{
++	unsigned long flags;
++	int success = 0;
++	long old_state;
++	struct rq *rq;
++
++	rq = time_task_grq_lock(p, &flags);
++	old_state = p->state;
++	if (!(old_state & state))
++		goto out_unlock;
++
++	/*
++	 * Note this catches tasks that are running and queued, but returns
++	 * false during the context switch when they're running and no
++	 * longer queued.
++	 */
++	if (task_queued(p))
++		goto out_running;
++
++	activate_task(p, rq);
++	/*
++	 * Sync wakeups (i.e. those types of wakeups where the waker
++	 * has indicated that it will leave the CPU in short order)
++	 * don't trigger a preemption if there are no idle cpus,
++	 * instead waiting for current to deschedule.
++	 */
++	if (!sync || (sync && suitable_idle_cpus(p)))
++		try_preempt(p);
++	success = 1;
++
++out_running:
++	trace_sched_wakeup(rq, p, success);
++	p->state = TASK_RUNNING;
++out_unlock:
++	task_grq_unlock(&flags);
++	return success;
++}
++
++/**
++ * 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 try_to_wake_up(p, TASK_ALL, 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.
++ */
++void sched_fork(struct task_struct *p, int clone_flags)
++{
++	int cpu = get_cpu();
++	struct rq *rq;
++
++#ifdef CONFIG_PREEMPT_NOTIFIERS
++	INIT_HLIST_HEAD(&p->preempt_notifiers);
++#endif
++	/*
++	 * We mark the process as running here, but have not actually
++	 * inserted it onto the runqueue yet. 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;
++	set_task_cpu(p, cpu);
++
++	/* Should be reset in fork.c but done here for ease of bfs patching */
++	p->se.sum_exec_runtime = p->stime_pc = p->utime_pc = 0;
++
++	/*
++	 * Make sure we do not leak PI boosting priority to the child:
++	 */
++	p->prio = current->normal_prio;
++
++	INIT_LIST_HEAD(&p->rt.run_list);
++#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
++	if (unlikely(sched_info_on()))
++		memset(&p->sched_info, 0, sizeof(p->sched_info));
++#endif
++
++	p->oncpu = 0;
++
++#ifdef CONFIG_PREEMPT
++	/* Want to start with kernel preemption disabled. */
++	task_thread_info(p)->preempt_count = 1;
++#endif
++	if (unlikely(p->policy == SCHED_FIFO))
++		goto out;
++	/*
++	 * Share the timeslice between parent and child, thus the
++	 * total amount of pending timeslices in the system doesn't change,
++	 * resulting in more scheduling fairness. If it's negative, it won't
++	 * matter since that's the same as being 0. current's time_slice is
++	 * actually in rq_time_slice when it's running.
++	 */
++	local_irq_disable();
++	rq = task_rq(current);
++	if (likely(rq->rq_time_slice > 0)) {
++		rq->rq_time_slice /= 2;
++		/*
++		 * The remainder of the first timeslice might be recovered by
++		 * the parent if the child exits early enough.
++		 */
++		p->first_time_slice = 1;
++	}
++	p->rt.time_slice = rq->rq_time_slice;
++	local_irq_enable();
++out:
++	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 clone_flags)
++{
++	struct task_struct *parent;
++	unsigned long flags;
++	struct rq *rq;
++
++	rq = time_task_grq_lock(p, &flags); ;
++	parent = p->parent;
++	BUG_ON(p->state != TASK_RUNNING);
++	set_task_cpu(p, task_cpu(parent));
++
++	activate_task(p, rq);
++	trace_sched_wakeup_new(rq, p, 1);
++	if (!(clone_flags & CLONE_VM) && rq->curr == parent &&
++		!suitable_idle_cpus(p)) {
++		/*
++		 * The VM isn't cloned, so we're in a good position to
++		 * do child-runs-first in anticipation of an exec. This
++		 * usually avoids a lot of COW overhead.
++		 */
++			resched_task(parent);
++	} else
++		try_preempt(p);
++	task_grq_unlock(&flags);
++}
++
++/*
++ * Potentially available exiting-child timeslices are
++ * retrieved here - this way the parent does not get
++ * penalized for creating too many threads.
++ *
++ * (this cannot be used to 'generate' timeslices
++ * artificially, because any timeslice recovered here
++ * was given away by the parent in the first place.)
++ */
++void sched_exit(struct task_struct *p)
++{
++	struct task_struct *parent;
++	unsigned long flags;
++	struct rq *rq;
++
++	if (p->first_time_slice) {
++		parent = p->parent;
++		rq = task_grq_lock(parent, &flags);
++		parent->rt.time_slice += p->rt.time_slice;
++		if (unlikely(parent->rt.time_slice > timeslice()))
++			parent->rt.time_slice = timeslice();
++		task_grq_unlock(&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;
++	struct hlist_node *node;
++
++	hlist_for_each_entry(notifier, node, &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;
++	struct hlist_node *node;
++
++	hlist_for_each_entry(notifier, node, &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
++ * @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)
++{
++	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 inline void finish_task_switch(struct rq *rq, struct task_struct *prev)
++	__releases(grq.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;
++	finish_arch_switch(prev);
++	perf_counter_task_sched_in(current, cpu_of(rq));
++	finish_lock_switch(rq, prev);
++
++	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);
++	}
++}
++
++/**
++ * 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(grq.lock)
++{
++	struct rq *rq = this_rq();
++
++	finish_task_switch(rq, prev);
++#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(current->pid, 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);
++	trace_sched_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_enter_lazy_cpu_mode();
++
++	if (unlikely(!mm)) {
++		next->active_mm = oldmm;
++		atomic_inc(&oldmm->mm_count);
++		enter_lazy_tlb(oldmm, next);
++	} else
++		switch_mm(oldmm, mm, next);
++
++	if (unlikely(!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(&grq.lock.dep_map, 1, _THIS_IP_);
++#endif
++
++	/* 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, nr_uninterruptible and nr_context_switches:
++ *
++ * externally visible scheduler statistics: current number of runnable
++ * threads, current number of uninterruptible-sleeping threads, total
++ * number of context switches performed since bootup. All are measured
++ * without grabbing the grq lock but the occasional inaccurate result
++ * doesn't matter so long as it's positive.
++ */
++unsigned long nr_running(void)
++{
++	long nr = grq.nr_running;
++
++	if (unlikely(nr < 0))
++		nr = 0;
++	return (unsigned long)nr;
++}
++
++unsigned long nr_uninterruptible(void)
++{
++	unsigned long nu = grq.nr_uninterruptible;
++
++	if (unlikely(nu < 0))
++		nu = 0;
++	return nu;
++}
++
++unsigned long long nr_context_switches(void)
++{
++	long long ns = grq.nr_switches;
++
++	/* This is of course impossible */
++	if (unlikely(ns < 0))
++		ns = 1;
++	return (long long)ns;
++}
++
++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_active(void)
++{
++	return nr_running() + nr_uninterruptible();
++}
++
++/* Variables and functions for calc_load */
++static unsigned long calc_load_update;
++unsigned long avenrun[3];
++EXPORT_SYMBOL(avenrun);
++
++/**
++ * 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 unsigned long
++calc_load(unsigned long load, unsigned long exp, unsigned long active)
++{
++	load *= exp;
++	load += active * (FIXED_1 - exp);
++	return load >> FSHIFT;
++}
++
++/*
++ * calc_load - update the avenrun load estimates every LOAD_FREQ seconds.
++ */
++void calc_global_load(void)
++{
++	long active;
++
++	if (time_before(jiffies, calc_load_update))
++		return;
++	active = nr_active() * FIXED_1;
++
++	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 = jiffies + LOAD_FREQ;
++}
++
++DEFINE_PER_CPU(struct kernel_stat, kstat);
++
++EXPORT_PER_CPU_SYMBOL(kstat);
++
++/*
++ * On each tick, see what percentage of that tick was attributed to each
++ * component and add the percentage to the _pc values. Once a _pc value has
++ * accumulated one tick's worth, account for that. This means the total
++ * percentage of load components will always be 100 per tick.
++ */
++static void pc_idle_time(struct rq *rq, unsigned long pc)
++{
++	struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
++	cputime64_t tmp = cputime_to_cputime64(jiffies_to_cputime(1));
++
++	if (atomic_read(&rq->nr_iowait) > 0) {
++		rq->iowait_pc += pc;
++		if (rq->iowait_pc >= 100) {
++			rq->iowait_pc %= 100;
++			cpustat->iowait = cputime64_add(cpustat->iowait, tmp);
++		}
++	} else {
++		rq->idle_pc += pc;
++		if (rq->idle_pc >= 100) {
++			rq->idle_pc %= 100;
++			cpustat->idle = cputime64_add(cpustat->idle, tmp);
++		}
++	}
++}
++
++static void
++pc_system_time(struct rq *rq, struct task_struct *p, int hardirq_offset,
++	       unsigned long pc, unsigned long ns)
++{
++	struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
++	cputime_t one_jiffy = jiffies_to_cputime(1);
++	cputime_t one_jiffy_scaled = cputime_to_scaled(one_jiffy);
++	cputime64_t tmp = cputime_to_cputime64(one_jiffy);
++
++	p->stime_pc += pc;
++	if (p->stime_pc >= 100) {
++		p->stime_pc -= 100;
++		p->stime = cputime_add(p->stime, one_jiffy);
++		p->stimescaled = cputime_add(p->stimescaled, one_jiffy_scaled);
++		account_group_system_time(p, one_jiffy);
++		acct_update_integrals(p);
++	}
++	p->se.sum_exec_runtime += ns;
++
++	if (hardirq_count() - hardirq_offset)
++		rq->irq_pc += pc;
++	else if (softirq_count()) {
++		rq->softirq_pc += pc;
++		if (rq->softirq_pc >= 100) {
++			rq->softirq_pc %= 100;
++			cpustat->softirq = cputime64_add(cpustat->softirq, tmp);
++		}
++	} else {
++		rq->system_pc += pc;
++		if (rq->system_pc >= 100) {
++			rq->system_pc %= 100;
++			cpustat->system = cputime64_add(cpustat->system, tmp);
++		}
++	}
++}
++
++static void pc_user_time(struct rq *rq, struct task_struct *p,
++			 unsigned long pc, unsigned long ns)
++{
++	struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
++	cputime_t one_jiffy = jiffies_to_cputime(1);
++	cputime_t one_jiffy_scaled = cputime_to_scaled(one_jiffy);
++	cputime64_t tmp = cputime_to_cputime64(one_jiffy);
++
++	p->utime_pc += pc;
++	if (p->utime_pc >= 100) {
++		p->utime_pc -= 100;
++		p->utime = cputime_add(p->utime, one_jiffy);
++		p->utimescaled = cputime_add(p->utimescaled, one_jiffy_scaled);
++		account_group_user_time(p, one_jiffy);
++		acct_update_integrals(p);
++	}
++	p->se.sum_exec_runtime += ns;
++
++	if (TASK_NICE(p) > 0 || idleprio_task(p)) {
++		rq->nice_pc += pc;
++		if (rq->nice_pc >= 100) {
++			rq->nice_pc %= 100;
++			cpustat->nice = cputime64_add(cpustat->nice, tmp);
++		}
++	} else {
++		rq->user_pc += pc;
++		if (rq->user_pc >= 100) {
++			rq->user_pc %= 100;
++			cpustat->user = cputime64_add(cpustat->user, tmp);
++		}
++	}
++}
++
++/* Convert nanoseconds to percentage of one tick. */
++#define NS_TO_PC(NS)	(NS * 100 / JIFFIES_TO_NS(1))
++
++/*
++ * This is called on clock ticks and on context switches.
++ * Bank in p->se.sum_exec_runtime the ns elapsed since the last tick or switch.
++ * CPU scheduler quota accounting is also performed here in microseconds.
++ * The value returned from sched_clock() occasionally gives bogus values so
++ * some sanity checking is required. Time is supposed to be banked all the
++ * time so default to half a tick to make up for when sched_clock reverts
++ * to just returning jiffies, and for hardware that can't do tsc.
++ */
++static void
++update_cpu_clock(struct rq *rq, struct task_struct *p, int tick)
++{
++	long time_diff = rq->clock - p->last_ran;
++	long account_ns = rq->clock - rq->timekeep_clock;
++	struct task_struct *idle = rq->idle;
++	unsigned long account_pc;
++
++	/*
++	 * There should be less than or equal to one jiffy worth, and not
++	 * negative/overflow. time_diff is only used for internal scheduler
++	 * time_slice accounting.
++	 */
++	if (time_diff <= 0)
++		time_diff = JIFFIES_TO_NS(1) / 2;
++	else if (time_diff > JIFFIES_TO_NS(1))
++		time_diff = JIFFIES_TO_NS(1);
++
++	if (unlikely(account_ns < 0))
++		account_ns = 0;
++
++	account_pc = NS_TO_PC(account_ns);
++
++	if (tick) {
++		int user_tick = user_mode(get_irq_regs());
++
++		/* Accurate tick timekeeping */
++		if (user_tick)
++			pc_user_time(rq, p, account_pc, account_ns);
++		else if (p != idle || (irq_count() != HARDIRQ_OFFSET))
++			pc_system_time(rq, p, HARDIRQ_OFFSET,
++				       account_pc, account_ns);
++		else
++			pc_idle_time(rq, account_pc);
++	} else {
++		/* Accurate subtick timekeeping */
++		if (p == idle)
++			pc_idle_time(rq, account_pc);
++		else
++			pc_user_time(rq, p, account_pc, account_ns);
++	}
++
++	/* time_slice accounting is done in usecs to avoid overflow on 32bit */
++	if (rq->rq_policy != SCHED_FIFO && p != idle)
++		rq->rq_time_slice -= time_diff / 1000;
++	p->last_ran = rq->timekeep_clock = rq->clock;
++}
++
++/*
++ * 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_grq_lock() held on @rq.
++ */
++static u64 do_task_delta_exec(struct task_struct *p, struct rq *rq)
++{
++	u64 ns = 0;
++
++	if (p == rq->curr) {
++		update_rq_clock(rq);
++		ns = rq->clock - p->last_ran;
++		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_grq_lock(p, &flags);
++	ns = do_task_delta_exec(p, rq);
++	task_grq_unlock(&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_grq_lock(p, &flags);
++	ns = p->se.sum_exec_runtime + do_task_delta_exec(p, rq);
++	task_grq_unlock(&flags);
++
++	return ns;
++}
++
++/*
++ * Return sum_exec_runtime for the thread group.
++ * In case the task is currently running, return the sum plus current's
++ * pending runtime that have not been accounted yet.
++ *
++ * Note that the thread group might have other running tasks as well,
++ * so the return value not includes other pending runtime that other
++ * running tasks might have.
++ */
++unsigned long long thread_group_sched_runtime(struct task_struct *p)
++{
++	struct task_cputime totals;
++	unsigned long flags;
++	struct rq *rq;
++	u64 ns;
++
++	rq = task_grq_lock(p, &flags);
++	thread_group_cputime(p, &totals);
++	ns = totals.sum_exec_runtime + do_task_delta_exec(p, rq);
++	task_grq_unlock(&flags);
++
++	return ns;
++}
++
++/* Compatibility crap for removal */
++void account_user_time(struct task_struct *p, cputime_t cputime,
++		       cputime_t cputime_scaled)
++{
++}
++
++void account_idle_time(cputime_t cputime)
++{
++}
++
++/*
++ * Account guest cpu time to a process.
++ * @p: the process that the cpu time gets accounted to
++ * @cputime: the cpu time spent in virtual machine since the last update
++ * @cputime_scaled: cputime scaled by cpu frequency
++ */
++static void account_guest_time(struct task_struct *p, cputime_t cputime,
++			       cputime_t cputime_scaled)
++{
++	cputime64_t tmp;
++	struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
++
++	tmp = cputime_to_cputime64(cputime);
++
++	/* Add guest time to process. */
++	p->utime = cputime_add(p->utime, cputime);
++	p->utimescaled = cputime_add(p->utimescaled, cputime_scaled);
++	account_group_user_time(p, cputime);
++	p->gtime = cputime_add(p->gtime, cputime);
++
++	/* Add guest time to cpustat. */
++	cpustat->user = cputime64_add(cpustat->user, tmp);
++	cpustat->guest = cputime64_add(cpustat->guest, tmp);
++}
++
++/*
++ * Account system cpu time to a process.
++ * @p: the process that the cpu time gets accounted to
++ * @hardirq_offset: the offset to subtract from hardirq_count()
++ * @cputime: the cpu time spent in kernel space since the last update
++ * @cputime_scaled: cputime scaled by cpu frequency
++ * This is for guest only now.
++ */
++void account_system_time(struct task_struct *p, int hardirq_offset,
++			 cputime_t cputime, cputime_t cputime_scaled)
++{
++
++	if ((p->flags & PF_VCPU) && (irq_count() - hardirq_offset == 0))
++		account_guest_time(p, cputime, cputime_scaled);
++}
++
++/*
++ * Account for involuntary wait time.
++ * @steal: the cpu time spent in involuntary wait
++ */
++void account_steal_time(cputime_t cputime)
++{
++	struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
++	cputime64_t cputime64 = cputime_to_cputime64(cputime);
++
++	cpustat->steal = cputime64_add(cpustat->steal, cputime64);
++}
++
++/*
++ * Account for idle time.
++ * @cputime: the cpu time spent in idle wait
++ */
++static void account_idle_times(cputime_t cputime)
++{
++	struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
++	cputime64_t cputime64 = cputime_to_cputime64(cputime);
++	struct rq *rq = this_rq();
++
++	if (atomic_read(&rq->nr_iowait) > 0)
++		cpustat->iowait = cputime64_add(cpustat->iowait, cputime64);
++	else
++		cpustat->idle = cputime64_add(cpustat->idle, cputime64);
++}
++
++#ifndef CONFIG_VIRT_CPU_ACCOUNTING
++
++void account_process_tick(struct task_struct *p, int user_tick)
++{
++}
++
++/*
++ * Account multiple ticks of steal time.
++ * @p: the process from which the cpu time has been stolen
++ * @ticks: number of stolen ticks
++ */
++void account_steal_ticks(unsigned long ticks)
++{
++	account_steal_time(jiffies_to_cputime(ticks));
++}
++
++/*
++ * Account multiple ticks of idle time.
++ * @ticks: number of stolen ticks
++ */
++void account_idle_ticks(unsigned long ticks)
++{
++	account_idle_times(jiffies_to_cputime(ticks));
++}
++#endif
++
++/*
++ * Functions to test for when SCHED_ISO tasks have used their allocated
++ * quota as real time scheduling and convert them back to SCHED_NORMAL.
++ * Where possible, the data is tested lockless, to avoid grabbing grq_lock
++ * because the occasional inaccurate result won't matter. However the
++ * data is only ever modified under lock.
++ */
++static void set_iso_refractory(void)
++{
++	grq_lock();
++	grq.iso_refractory = 1;
++	grq_unlock();
++}
++
++static void clear_iso_refractory(void)
++{
++	grq_lock();
++	grq.iso_refractory = 0;
++	grq_unlock();
++}
++
++/*
++ * Test if SCHED_ISO tasks have run longer than their alloted period as RT
++ * tasks and set the refractory flag if necessary. There is 10% hysteresis
++ * for unsetting the flag.
++ */
++static unsigned int test_ret_isorefractory(struct rq *rq)
++{
++	if (likely(!grq.iso_refractory)) {
++		if (grq.iso_ticks / ISO_PERIOD > sched_iso_cpu)
++			set_iso_refractory();
++	} else {
++		if (grq.iso_ticks / ISO_PERIOD < (sched_iso_cpu * 90 / 100))
++			clear_iso_refractory();
++	}
++	return grq.iso_refractory;
++}
++
++static void iso_tick(void)
++{
++	grq_lock();
++	grq.iso_ticks += 100;
++	grq_unlock();
++}
++
++/* No SCHED_ISO task was running so decrease rq->iso_ticks */
++static inline void no_iso_tick(void)
++{
++	if (grq.iso_ticks) {
++		grq_lock();
++		grq.iso_ticks = grq.iso_ticks * (ISO_PERIOD - 1) / ISO_PERIOD;
++		grq_unlock();
++	}
++}
++
++static int rq_running_iso(struct rq *rq)
++{
++	return rq->rq_prio == ISO_PRIO;
++}
++
++/* This manages tasks that have run out of timeslice during a scheduler_tick */
++static void task_running_tick(struct rq *rq)
++{
++	struct task_struct *p;
++
++	/*
++	 * If a SCHED_ISO task is running we increment the iso_ticks. In
++	 * order to prevent SCHED_ISO tasks from causing starvation in the
++	 * presence of true RT tasks we account those as iso_ticks as well.
++	 */
++	if ((rt_queue(rq) || (iso_queue(rq) && !grq.iso_refractory))) {
++		if (grq.iso_ticks <= (ISO_PERIOD * 100) - 100)
++			iso_tick();
++	} else
++		no_iso_tick();
++
++	if (iso_queue(rq)) {
++		if (unlikely(test_ret_isorefractory(rq))) {
++			if (rq_running_iso(rq)) {
++				/*
++				 * SCHED_ISO task is running as RT and limit
++				 * has been hit. Force it to reschedule as
++				 * SCHED_NORMAL by zeroing its time_slice
++				 */
++				rq->rq_time_slice = 0;
++			}
++		}
++	}
++
++	/* SCHED_FIFO tasks never run out of timeslice. */
++	if (rq_idle(rq) || rq->rq_time_slice > 0 || rq->rq_policy == SCHED_FIFO)
++		return;
++
++	/* p->rt.time_slice <= 0. We only modify task_struct under grq lock */
++	grq_lock();
++	p = rq->curr;
++	if (likely(task_running(p))) {
++		requeue_task(p);
++		set_tsk_need_resched(p);
++	}
++	grq_unlock();
++}
++
++void wake_up_idle_cpu(int cpu);
++
++/*
++ * This function gets called by the timer code, with HZ frequency.
++ * We call it with interrupts disabled. The data modified is all
++ * local to struct rq so we don't need to grab grq lock.
++ */
++void scheduler_tick(void)
++{
++	int cpu = smp_processor_id();
++	struct rq *rq = cpu_rq(cpu);
++
++	sched_clock_tick();
++	update_rq_clock(rq);
++	update_cpu_clock(rq, rq->curr, 1);
++	if (!rq_idle(rq))
++		task_running_tick(rq);
++	else {
++		no_iso_tick();
++		if (unlikely(queued_notrunning()))
++			set_tsk_need_resched(rq->idle);
++	}
++}
++
++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
++
++/*
++ * Deadline is "now" in jiffies + (offset by priority). Setting the deadline
++ * is the key to everything. It distributes cpu fairly amongst tasks of the
++ * same nice value, it proportions cpu according to nice level, it means the
++ * task that last woke up the longest ago has the earliest deadline, thus
++ * ensuring that interactive tasks get low latency on wake up.
++ */
++static inline int prio_deadline_diff(struct task_struct *p)
++{
++	return (pratio(p) * rr_interval * HZ / 1000 / 100) ? : 1;
++}
++
++static inline int longest_deadline(void)
++{
++	return (prio_ratios[39] * rr_interval * HZ / 1000 / 100);
++}
++
++/*
++ * SCHED_IDLE tasks still have a deadline set, but offset by to nice +19.
++ * This allows nice levels to work between IDLEPRIO tasks and gives a
++ * deadline longer than nice +19 for when they're scheduled as SCHED_NORMAL
++ * tasks.
++ */
++static inline void time_slice_expired(struct task_struct *p)
++{
++	reset_first_time_slice(p);
++	p->rt.time_slice = timeslice();
++	p->deadline = jiffies + prio_deadline_diff(p);
++	if (idleprio_task(p))
++		p->deadline += longest_deadline();
++}
++
++static inline void check_deadline(struct task_struct *p)
++{
++	if (p->rt.time_slice <= 0)
++		time_slice_expired(p);
++}
++
++/*
++ * O(n) lookup of all tasks in the global runqueue. The real brainfuck
++ * of lock contention and O(n). It's not really O(n) as only the queued,
++ * but not running tasks are scanned, and is O(n) queued in the worst case
++ * scenario only because the right task can be found before scanning all of
++ * them.
++ * Tasks are selected in this order:
++ * Real time tasks are selected purely by their static priority and in the
++ * order they were queued, so the lowest value idx, and the first queued task
++ * of that priority value is chosen.
++ * If no real time tasks are found, the SCHED_ISO priority is checked, and
++ * all SCHED_ISO tasks have the same priority value, so they're selected by
++ * the earliest deadline value.
++ * If no SCHED_ISO tasks are found, SCHED_NORMAL tasks are selected by the
++ * earliest deadline.
++ * Finally if no SCHED_NORMAL tasks are found, SCHED_IDLEPRIO tasks are
++ * selected by the earliest deadline.
++ */
++static inline struct
++task_struct *earliest_deadline_task(struct rq *rq, struct task_struct *idle)
++{
++	unsigned long dl, earliest_deadline = 0; /* Initialise to silence compiler */
++	struct task_struct *p, *edt;
++	unsigned int cpu = rq->cpu;
++	struct list_head *queue;
++	int idx = 0;
++
++	edt = idle;
++retry:
++	idx = find_next_bit(grq.prio_bitmap, PRIO_LIMIT, idx);
++	if (idx >= PRIO_LIMIT)
++		goto out;
++	queue = &grq.queue[idx];
++	list_for_each_entry(p, queue, rt.run_list) {
++		/* Make sure cpu affinity is ok */
++		if (!cpu_isset(cpu, p->cpus_allowed))
++			continue;
++		if (idx < MAX_RT_PRIO) {
++			/* We found an rt task */
++			edt = p;
++			goto out_take;
++		}
++
++		/*
++		 * No rt task, select the earliest deadline task now.
++		 * On the 1st run the 2nd condition is never used, so
++		 * there is no need to initialise earliest_deadline
++		 * before. Normalise all old deadlines to now.
++		 */
++		if (time_before(p->deadline, jiffies))
++			dl = jiffies;
++		else
++			dl = p->deadline;
++
++		if (edt == idle ||
++		    time_before(dl, earliest_deadline)) {
++			earliest_deadline = dl;
++			edt = p;
++		}
++	}
++	if (edt == idle) {
++		if (++idx < PRIO_LIMIT)
++			goto retry;
++		goto out;
++	}
++out_take:
++	take_task(rq, edt);
++out:
++	return edt;
++}
++
++#ifdef CONFIG_SMP
++static inline void set_cpuidle_map(unsigned long cpu)
++{
++	cpu_set(cpu, grq.cpu_idle_map);
++}
++
++static inline void clear_cpuidle_map(unsigned long cpu)
++{
++	cpu_clear(cpu, grq.cpu_idle_map);
++}
++
++#else /* CONFIG_SMP */
++static inline void set_cpuidle_map(unsigned long cpu)
++{
++}
++
++static inline void clear_cpuidle_map(unsigned long cpu)
++{
++}
++#endif /* !CONFIG_SMP */
++
++/*
++ * Print scheduling while atomic bug:
++ */
++static noinline void __schedule_bug(struct task_struct *prev)
++{
++	struct pt_regs *regs = get_irq_regs();
++
++	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);
++
++	if (regs)
++		show_regs(regs);
++	else
++		dump_stack();
++}
++
++/*
++ * 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);
++
++	profile_hit(SCHED_PROFILING, __builtin_return_address(0));
++
++	schedstat_inc(this_rq(), sched_count);
++#ifdef CONFIG_SCHEDSTATS
++	if (unlikely(prev->lock_depth >= 0)) {
++		schedstat_inc(this_rq(), bkl_count);
++		schedstat_inc(prev, sched_info.bkl_count);
++	}
++#endif
++}
++
++/*
++ * schedule() is the main scheduler function.
++ */
++asmlinkage void __sched __schedule(void)
++{
++	struct task_struct *prev, *next, *idle;
++	int deactivate = 0, cpu;
++	long *switch_count;
++	struct rq *rq;
++	u64 now;
++
++	cpu = smp_processor_id();
++	rq = this_rq();
++	rcu_qsctr_inc(cpu);
++	prev = rq->curr;
++	switch_count = &prev->nivcsw;
++
++	release_kernel_lock(prev);
++need_resched_nonpreemptible:
++
++	schedule_debug(prev);
++	idle = rq->idle;
++	/*
++	 * The idle thread is not allowed to schedule!
++	 * Remove this check after it has been exercised a bit.
++	 */
++	if (unlikely(prev == idle) && prev->state != TASK_RUNNING) {
++		printk(KERN_ERR "bad: scheduling from the idle thread!\n");
++		dump_stack();
++	}
++
++	grq_lock_irq();
++	update_rq_clock(rq);
++	now = rq->clock;
++	update_cpu_clock(rq, prev, 0);
++
++	clear_tsk_need_resched(prev);
++
++	if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) {
++		if (unlikely(signal_pending_state(prev->state, prev)))
++			prev->state = TASK_RUNNING;
++		else
++			deactivate = 1;
++		switch_count = &prev->nvcsw;
++	}
++
++	if (prev != idle) {
++		/* Update all the information stored on struct rq */
++		prev->rt.time_slice = rq->rq_time_slice;
++		prev->deadline = rq->rq_deadline;
++		check_deadline(prev);
++		return_task(prev, deactivate);
++	}
++
++	if (likely(queued_notrunning())) {
++		next = earliest_deadline_task(rq, idle);
++	} else {
++		next = idle;
++		schedstat_inc(rq, sched_goidle);
++	}
++
++	if (next == rq->idle)
++		set_cpuidle_map(cpu);
++	else
++		clear_cpuidle_map(cpu);
++
++	prefetch(next);
++	prefetch_stack(next);
++
++	prev->timestamp = prev->last_ran = now;
++
++	if (likely(prev != next)) {
++		rq->rq_time_slice = next->rt.time_slice;
++		rq->rq_deadline = next->deadline;
++		rq->rq_prio = next->prio;
++
++		sched_info_switch(prev, next);
++		grq.nr_switches++;
++		next->oncpu = 1;
++		prev->oncpu = 0;
++		rq->curr = next;
++		++*switch_count;
++
++		context_switch(rq, prev, next); /* unlocks the rq */
++		/*
++		 * the context switch might have flipped the stack from under
++		 * us, hence refresh the local variables.
++		 */
++		cpu = smp_processor_id();
++		rq = cpu_rq(cpu);
++	} else
++		grq_unlock_irq();
++
++	if (unlikely(reacquire_kernel_lock(current) < 0))
++		goto need_resched_nonpreemptible;
++}
++
++asmlinkage void __sched schedule(void)
++{
++need_resched:
++	preempt_disable();
++	__schedule();
++	preempt_enable_no_resched();
++	if (unlikely(test_thread_flag(TIF_NEED_RESCHED)))
++		goto need_resched;
++}
++EXPORT_SYMBOL(schedule);
++
++#ifdef CONFIG_SMP
++int mutex_spin_on_owner(struct mutex *lock, struct thread_info *owner)
++{
++	return 0;
++}
++#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 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(PREEMPT_ACTIVE);
++		schedule();
++		sub_preempt_count(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());
++
++	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 sync,
++			  void *key)
++{
++	return try_to_wake_up(curr->private, mode, sync);
++}
++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.
++ */
++void __wake_up_common(wait_queue_head_t *q, unsigned int mode,
++		      int nr_exclusive, int sync, void *key)
++{
++	struct list_head *tmp, *next;
++
++	list_for_each_safe(tmp, next, &q->task_list) {
++		wait_queue_t *curr = list_entry(tmp, wait_queue_t, task_list);
++		unsigned flags = curr->flags;
++
++		if (curr->func(curr, mode, sync, 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)
++{
++	__wake_up_common(q, mode, 1, 0, NULL);
++}
++
++void __wake_up_locked_key(wait_queue_head_t *q, unsigned int mode, void *key)
++{
++	__wake_up_common(q, mode, 1, 0, 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 sync = 1;
++
++	if (unlikely(!q))
++		return;
++
++	if (unlikely(!nr_exclusive))
++		sync = 0;
++
++	spin_lock_irqsave(&q->lock, flags);
++	__wake_up_common(q, mode, nr_exclusive, sync, key);
++	spin_unlock_irqrestore(&q->lock, flags);
++}
++EXPORT_SYMBOL_GPL(__wake_up_sync_key);
++
++/**
++ * __wake_up_sync - 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
++ *
++ * 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.
++ */
++void __wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr_exclusive)
++{
++	unsigned long flags;
++	int sync = 1;
++
++	if (unlikely(!q))
++		return;
++
++	if (unlikely(!nr_exclusive))
++		sync = 0;
++
++	spin_lock_irqsave(&q->lock, flags);
++	__wake_up_common(q, mode, nr_exclusive, sync, NULL);
++	spin_unlock_irqrestore(&q->lock, flags);
++}
++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 timeout, int state)
++{
++	if (!x->done) {
++		DECLARE_WAITQUEUE(wait, current);
++
++		wait.flags |= WQ_FLAG_EXCLUSIVE;
++		__add_wait_queue_tail(&x->wait, &wait);
++		do {
++			if (signal_pending_state(state, current)) {
++				timeout = -ERESTARTSYS;
++				break;
++			}
++			__set_current_state(state);
++			spin_unlock_irq(&x->wait.lock);
++			timeout = schedule_timeout(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 long __sched
++wait_for_common(struct completion *x, long timeout, int state)
++{
++	might_sleep();
++
++	spin_lock_irq(&x->wait.lock);
++	timeout = do_wait_for_common(x, timeout, state);
++	spin_unlock_irq(&x->wait.lock);
++	return timeout;
++}
++
++/**
++ * 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.
++ */
++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_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.
++ */
++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.
++ */
++unsigned 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.
++ */
++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);
++
++/**
++ *	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)
++{
++	int ret = 1;
++
++	spin_lock_irq(&x->wait.lock);
++	if (!x->done)
++		ret = 0;
++	else
++		x->done--;
++	spin_unlock_irq(&x->wait.lock);
++	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)
++{
++	int ret = 1;
++
++	spin_lock_irq(&x->wait.lock);
++	if (!x->done)
++		ret = 0;
++	spin_unlock_irq(&x->wait.lock);
++	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)
++{
++	unsigned long flags;
++	int queued, oldprio;
++	struct rq *rq;
++
++	BUG_ON(prio < 0 || prio > MAX_PRIO);
++
++	rq = time_task_grq_lock(p, &flags);
++
++	oldprio = p->prio;
++	queued = task_queued_only(p);
++	if (queued)
++		dequeue_task(p);
++	p->prio = prio;
++	if (task_running(p) && prio > oldprio)
++		resched_task(p);
++	if (queued) {
++		enqueue_task(p);
++		try_preempt(p);
++	}
++
++	task_grq_unlock(&flags);
++}
++
++#endif
++
++/*
++ * Adjust the deadline for when the priority is to change, before it's
++ * changed.
++ */
++static void adjust_deadline(struct task_struct *p, int new_prio)
++{
++	p->deadline += (prio_ratios[USER_PRIO(new_prio)] - pratio(p)) *
++			rr_interval * HZ / 1000 / 100;
++}
++
++void set_user_nice(struct task_struct *p, long nice)
++{
++	int queued, new_static;
++	unsigned long flags;
++	struct rq *rq;
++
++	if (TASK_NICE(p) == nice || nice < -20 || nice > 19)
++		return;
++	new_static = NICE_TO_PRIO(nice);
++	/*
++	 * We have to be careful, if called from sys_setpriority(),
++	 * the task might be in the middle of scheduling on another CPU.
++	 */
++	rq = time_task_grq_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
++	 * not SCHED_NORMAL/SCHED_BATCH:
++	 */
++	if (has_rt_policy(p)) {
++		p->static_prio = new_static;
++		goto out_unlock;
++	}
++	queued = task_queued_only(p);
++	/*
++	 * If p is actually running, we don't need to do anything when
++	 * changing the priority because the grq is unaffected.
++	 */
++	if (queued)
++		dequeue_task(p);
++
++	adjust_deadline(p, new_static);
++	p->static_prio = new_static;
++	p->prio = effective_prio(p);
++
++	if (queued) {
++		enqueue_task(p);
++		try_preempt(p);
++	}
++
++	/* Just resched the task, schedule() will know what to do. */
++	if (task_running(p))
++		resched_task(p);
++out_unlock:
++	task_grq_unlock(&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 <= p->signal->rlim[RLIMIT_NICE].rlim_cur ||
++		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 -100. Normal tasks are centered
++ * around 1, value goes from 0 (SCHED_ISO) up to 82 (nice +19
++ * SCHED_IDLE).
++ */
++int task_prio(const struct task_struct *p)
++{
++	int delta, prio = p->prio - MAX_RT_PRIO;
++
++	/* rt tasks and iso tasks */
++	if (prio <= 0)
++		goto out;
++
++	delta = (p->deadline - jiffies) * 40 / longest_deadline();
++	if (delta > 0 && delta <= 80)
++		prio += delta;
++out:
++	return 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_GPL(task_nice);
++
++/**
++ * idle_cpu - is a given cpu idle currently?
++ * @cpu: the processor in question.
++ */
++int idle_cpu(int cpu)
++{
++	return cpu_curr(cpu) == cpu_rq(cpu)->idle;
++}
++
++/**
++ * 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 inline struct task_struct *find_process_by_pid(pid_t pid)
++{
++	return pid ? find_task_by_vpid(pid) : current;
++}
++
++/* Actually do priority change: must hold grq lock. */
++static void __setscheduler(struct task_struct *p, int policy, int prio)
++{
++	BUG_ON(task_queued_only(p));
++
++	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);
++	/*
++	 * Reschedule if running. schedule() will know if it can continue
++	 * running or not.
++	 */
++	if (task_running(p))
++		resched_task(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 = (cred->euid == pcred->euid ||
++		 cred->euid == pcred->uid);
++	rcu_read_unlock();
++	return match;
++}
++
++static int __sched_setscheduler(struct task_struct *p, int policy,
++		       struct sched_param *param, bool user)
++{
++	struct sched_param zero_param = { .sched_priority = 0 };
++	int queued, retval, oldprio, oldpolicy = -1;
++	unsigned long flags, rlim_rtprio = 0;
++	struct rq *rq;
++
++	/* may grab non-irq protected spin_locks */
++	BUG_ON(in_interrupt());
++
++	if (is_rt_policy(policy) && !capable(CAP_SYS_NICE)) {
++		unsigned long lflags;
++
++		if (!lock_task_sighand(p, &lflags))
++			return -ESRCH;
++		rlim_rtprio = p->signal->rlim[RLIMIT_RTPRIO].rlim_cur;
++		unlock_task_sighand(p, &lflags);
++		if (rlim_rtprio)
++			goto recheck;
++		/*
++		 * If the caller requested an RT policy without having the
++		 * necessary rights, we downgrade the policy to SCHED_ISO.
++		 * We also set the parameter to zero to pass the checks.
++		 */
++		policy = SCHED_ISO;
++		param = &zero_param;
++	}
++recheck:
++	/* double check policy once rq lock held */
++	if (policy < 0)
++		policy = oldpolicy = p->policy;
++	else if (!SCHED_RANGE(policy))
++		return -EINVAL;
++	/*
++	 * Valid priorities for SCHED_FIFO and SCHED_RR are
++	 * 1..MAX_USER_RT_PRIO-1, valid priority for SCHED_NORMAL and
++	 * SCHED_BATCH 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 (is_rt_policy(policy) != (param->sched_priority != 0))
++		return -EINVAL;
++
++	/*
++	 * Allow unprivileged RT tasks to decrease priority:
++	 */
++	if (user && !capable(CAP_SYS_NICE)) {
++		if (is_rt_policy(policy)) {
++			/* 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;
++		} else {
++			switch (p->policy) {
++				/*
++				 * Can only downgrade policies but not back to
++				 * SCHED_NORMAL
++				 */
++				case SCHED_ISO:
++					if (policy == SCHED_ISO)
++						goto out;
++					if (policy == SCHED_NORMAL)
++						return -EPERM;
++					break;
++				case SCHED_BATCH:
++					if (policy == SCHED_BATCH)
++						goto out;
++					if (policy != SCHED_IDLE)
++					    	return -EPERM;
++					break;
++				case SCHED_IDLE:
++					if (policy == SCHED_IDLE)
++						goto out;
++					return -EPERM;
++				default:
++					break;
++			}
++		}
++
++		/* can't change other user's priorities */
++		if (!check_same_owner(p))
++			return -EPERM;
++	}
++
++	retval = security_task_setscheduler(p, policy, param);
++	if (retval)
++		return retval;
++	/*
++	 * make sure no PI-waiters arrive (or leave) while we are
++	 * changing the priority of the task:
++	 */
++	spin_lock_irqsave(&p->pi_lock, flags);
++	/*
++	 * To be able to change p->policy safely, the apropriate
++	 * runqueue lock must be held.
++	 */
++	rq = __task_grq_lock(p);
++	/* recheck policy now with rq lock held */
++	if (unlikely(oldpolicy != -1 && oldpolicy != p->policy)) {
++		__task_grq_unlock();
++		spin_unlock_irqrestore(&p->pi_lock, flags);
++		policy = oldpolicy = -1;
++		goto recheck;
++	}
++	update_rq_clock(rq);
++	queued = task_queued_only(p);
++	if (queued)
++		dequeue_task(p);
++	oldprio = p->prio;
++	__setscheduler(p, policy, param->sched_priority);
++	if (queued) {
++		enqueue_task(p);
++		try_preempt(p);
++	}
++	__task_grq_unlock();
++	spin_unlock_irqrestore(&p->pi_lock, flags);
++
++	rt_mutex_adjust_pi(p);
++out:
++	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,
++		       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,
++			       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.
++ */
++asmlinkage long sys_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 = -EINVAL;
++
++	if (pid < 0)
++		goto out_nounlock;
++
++	retval = -ESRCH;
++	read_lock(&tasklist_lock);
++	p = find_process_by_pid(pid);
++	if (p) {
++		retval = security_task_getscheduler(p);
++		if (!retval)
++			retval = p->policy;
++	}
++	read_unlock(&tasklist_lock);
++
++out_nounlock:
++	return retval;
++}
++
++/**
++ * sys_sched_getscheduler - 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 = -EINVAL;
++
++	if (!param || pid < 0)
++		goto out_nounlock;
++
++	read_lock(&tasklist_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;
++	read_unlock(&tasklist_lock);
++
++	/*
++	 * This one might sleep, we cannot do it with a spinlock held ...
++	 */
++	retval = copy_to_user(param, &lp, sizeof(*param)) ? -EFAULT : 0;
++
++out_nounlock:
++	return retval;
++
++out_unlock:
++	read_unlock(&tasklist_lock);
++	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();
++	read_lock(&tasklist_lock);
++
++	p = find_process_by_pid(pid);
++	if (!p) {
++		read_unlock(&tasklist_lock);
++		put_online_cpus();
++		return -ESRCH;
++	}
++
++	/*
++	 * It is not safe to call set_cpus_allowed with the
++	 * tasklist_lock held. We will bump the task_struct's
++	 * usage count and then drop tasklist_lock.
++	 */
++	get_task_struct(p);
++	read_unlock(&tasklist_lock);
++
++	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) && !capable(CAP_SYS_NICE))
++		goto out_unlock;
++
++	retval = security_task_setscheduler(p, 0, NULL);
++	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,
++			     cpumask_t *new_mask)
++{
++	if (len < sizeof(cpumask_t)) {
++		memset(new_mask, 0, sizeof(cpumask_t));
++	} else if (len > sizeof(cpumask_t)) {
++		len = sizeof(cpumask_t);
++	}
++	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, cpumask_t *mask)
++{
++	struct task_struct *p;
++	int retval;
++
++	mutex_lock(&sched_hotcpu_mutex);
++	read_lock(&tasklist_lock);
++
++	retval = -ESRCH;
++	p = find_process_by_pid(pid);
++	if (!p)
++		goto out_unlock;
++
++	retval = security_task_getscheduler(p);
++	if (retval)
++		goto out_unlock;
++
++	cpus_and(*mask, p->cpus_allowed, cpu_online_map);
++
++out_unlock:
++	read_unlock(&tasklist_lock);
++	mutex_unlock(&sched_hotcpu_mutex);
++	if (retval)
++		return retval;
++
++	return 0;
++}
++
++/**
++ * 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 < cpumask_size())
++		return -EINVAL;
++
++	if (!alloc_cpumask_var(&mask, GFP_KERNEL))
++		return -ENOMEM;
++
++	ret = sched_getaffinity(pid, mask);
++	if (ret == 0) {
++		if (copy_to_user(user_mask_ptr, mask, cpumask_size()))
++			ret = -EFAULT;
++		else
++			ret = cpumask_size();
++	}
++	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. It does this by
++ * refilling the timeslice, resetting the deadline and scheduling away.
++ */
++SYSCALL_DEFINE0(sched_yield)
++{
++	struct task_struct *p;
++
++	grq_lock_irq();
++	p = current;
++	schedstat_inc(this_rq(), yld_count);
++	update_rq_clock(task_rq(p));
++	time_slice_expired(p);
++	requeue_task(p);
++
++	/*
++	 * Since we are going to call schedule() anyway, there's
++	 * no need to preempt or enable interrupts:
++	 */
++	__release(grq.lock);
++	spin_release(&grq.lock.dep_map, 1, _THIS_IP_);
++	_raw_spin_unlock(&grq.lock);
++	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)
++{
++#ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
++	__might_sleep(__FILE__, __LINE__);
++#endif
++	/*
++	 * The BKS might be reacquired before we have dropped
++	 * PREEMPT_ACTIVE, which could trigger a second
++	 * cond_resched() call.
++	 */
++	do {
++		add_preempt_count(PREEMPT_ACTIVE);
++		schedule();
++		sub_preempt_count(PREEMPT_ACTIVE);
++	} while (need_resched());
++}
++
++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;
++
++	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.
++ *
++ * This is a shortcut for kernel-space yielding - it marks the
++ * thread runnable and calls sys_sched_yield().
++ */
++void __sched yield(void)
++{
++	set_current_state(TASK_RUNNING);
++	sys_sched_yield();
++}
++EXPORT_SYMBOL(yield);
++
++/*
++ * 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.
++ *
++ * But don't do that if it is a deliberate, throttling IO wait (this task
++ * has set its backing_dev_info: the queue against which it should throttle)
++ */
++void __sched io_schedule(void)
++{
++	struct rq *rq = &__raw_get_cpu_var(runqueues);
++
++	delayacct_blkio_start();
++	atomic_inc(&rq->nr_iowait);
++	schedule();
++	atomic_dec(&rq->nr_iowait);
++	delayacct_blkio_end();
++}
++EXPORT_SYMBOL(io_schedule);
++
++long __sched io_schedule_timeout(long timeout)
++{
++	struct rq *rq = &__raw_get_cpu_var(runqueues);
++	long ret;
++
++	delayacct_blkio_start();
++	atomic_inc(&rq->nr_iowait);
++	ret = schedule_timeout(timeout);
++	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_ISO:
++	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_ISO:
++	case SCHED_IDLE:
++		ret = 0;
++		break;
++	}
++	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;
++	int retval = -EINVAL;
++	struct timespec t;
++
++	if (pid < 0)
++		goto out_nounlock;
++
++	retval = -ESRCH;
++	read_lock(&tasklist_lock);
++	p = find_process_by_pid(pid);
++	if (!p)
++		goto out_unlock;
++
++	retval = security_task_getscheduler(p);
++	if (retval)
++		goto out_unlock;
++
++	t = ns_to_timespec(p->policy == SCHED_FIFO ? 0 :
++			   MS_TO_NS(task_timeslice(p)));
++	read_unlock(&tasklist_lock);
++	retval = copy_to_user(interval, &t, sizeof(t)) ? -EFAULT : 0;
++out_nounlock:
++	return retval;
++out_unlock:
++	read_unlock(&tasklist_lock);
++	return retval;
++}
++
++static const char stat_nam[] = TASK_STATE_TO_CHAR_STR;
++
++void sched_show_task(struct task_struct *p)
++{
++	unsigned long free = 0;
++	unsigned state;
++
++	state = p->state ? __ffs(p->state) + 1 : 0;
++	printk(KERN_INFO "%-13.13s %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
++	printk(KERN_CONT "%5lu %5d %6d 0x%08lx\n", free,
++		task_pid_nr(p), task_pid_nr(p->real_parent),
++		(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
++	read_lock(&tasklist_lock);
++	do_each_thread(g, p) {
++		/*
++		 * reset the NMI-timeout, listing all files on a slow
++		 * console might take alot 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();
++
++	read_unlock(&tasklist_lock);
++	/*
++	 * Only show locks if all tasks are dumped:
++	 */
++	if (state_filter == -1)
++		debug_show_all_locks();
++}
++
++/**
++ * 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;
++
++	time_grq_lock(rq, &flags);
++	idle->timestamp = idle->last_ran = rq->clock;
++	idle->state = TASK_RUNNING;
++	/* Setting prio to illegal value shouldn't matter when never queued */
++	idle->prio = rq->rq_prio = PRIO_LIMIT;
++	rq->rq_deadline = idle->deadline;
++	rq->rq_policy = idle->policy;
++	rq->rq_time_slice = idle->rt.time_slice;
++	idle->cpus_allowed = cpumask_of_cpu(cpu);
++	set_task_cpu(idle, cpu);
++	rq->curr = rq->idle = idle;
++	idle->oncpu = 1;
++	set_cpuidle_map(cpu);
++#ifdef CONFIG_HOTPLUG_CPU
++	idle->unplugged_mask = CPU_MASK_NONE;
++#endif
++	grq_unlock_irqrestore(&flags);
++
++	/* Set the preempt count _outside_ the spinlocks! */
++#if defined(CONFIG_PREEMPT) && !defined(CONFIG_PREEMPT_BKL)
++	task_thread_info(idle)->preempt_count = (idle->lock_depth >= 0);
++#else
++	task_thread_info(idle)->preempt_count = 0;
++#endif
++	ftrace_graph_init_task(idle);
++}
++
++/*
++ * In a system that switches off the HZ timer nohz_cpu_mask
++ * indicates which cpus entered this state. This is used
++ * in the rcu update to wait only for active cpus. For system
++ * which do not switch off the HZ timer nohz_cpu_mask should
++ * always be CPU_BITS_NONE.
++ */
++cpumask_var_t nohz_cpu_mask;
++
++#ifdef CONFIG_SMP
++#ifdef CONFIG_NO_HZ
++static struct {
++	atomic_t load_balancer;
++	cpumask_var_t cpu_mask;
++	cpumask_var_t ilb_grp_nohz_mask;
++} nohz ____cacheline_aligned = {
++	.load_balancer = ATOMIC_INIT(-1),
++};
++
++int get_nohz_load_balancer(void)
++{
++	return atomic_read(&nohz.load_balancer);
++}
++
++/*
++ * This routine will try to nominate the ilb (idle load balancing)
++ * owner among the cpus whose ticks are stopped. ilb owner will do the idle
++ * load balancing on behalf of all those cpus. If all the cpus in the system
++ * go into this tickless mode, then there will be no ilb owner (as there is
++ * no need for one) and all the cpus will sleep till the next wakeup event
++ * arrives...
++ *
++ * For the ilb owner, tick is not stopped. And this tick will be used
++ * for idle load balancing. ilb owner will still be part of
++ * nohz.cpu_mask..
++ *
++ * While stopping the tick, this cpu will become the ilb owner if there
++ * is no other owner. And will be the owner till that cpu becomes busy
++ * or if all cpus in the system stop their ticks at which point
++ * there is no need for ilb owner.
++ *
++ * When the ilb owner becomes busy, it nominates another owner, during the
++ * next busy scheduler_tick()
++ */
++int select_nohz_load_balancer(int stop_tick)
++{
++	int cpu = smp_processor_id();
++
++	if (stop_tick) {
++		cpu_rq(cpu)->in_nohz_recently = 1;
++
++		if (!cpu_active(cpu)) {
++			if (atomic_read(&nohz.load_balancer) != cpu)
++				return 0;
++
++			/*
++			 * If we are going offline and still the leader,
++			 * give up!
++			 */
++			if (atomic_cmpxchg(&nohz.load_balancer, cpu, -1) != cpu)
++				BUG();
++
++			return 0;
++		}
++
++		cpumask_set_cpu(cpu, nohz.cpu_mask);
++
++		/* time for ilb owner also to sleep */
++		if (cpumask_weight(nohz.cpu_mask) == num_online_cpus()) {
++			if (atomic_read(&nohz.load_balancer) == cpu)
++				atomic_set(&nohz.load_balancer, -1);
++			return 0;
++		}
++
++		if (atomic_read(&nohz.load_balancer) == -1) {
++			/* make me the ilb owner */
++			if (atomic_cmpxchg(&nohz.load_balancer, -1, cpu) == -1)
++				return 1;
++		} else if (atomic_read(&nohz.load_balancer) == cpu)
++			return 1;
++	} else {
++		if (!cpumask_test_cpu(cpu, nohz.cpu_mask))
++			return 0;
++
++		cpumask_clear_cpu(cpu, nohz.cpu_mask);
++
++		if (atomic_read(&nohz.load_balancer) == cpu)
++			if (atomic_cmpxchg(&nohz.load_balancer, cpu, -1) != cpu)
++				BUG();
++	}
++	return 0;
++}
++
++/*
++ * 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 wake_up_idle_cpu(int cpu)
++{
++	struct task_struct *idle;
++	struct rq *rq;
++
++	if (cpu == smp_processor_id())
++		return;
++
++	rq = cpu_rq(cpu);
++	idle = rq->idle;
++
++	/*
++	 * 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 (unlikely(rq->curr != idle))
++		return;
++
++	/*
++	 * 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(idle);
++
++	/* NEED_RESCHED must be visible before we test polling */
++	smp_mb();
++	if (!tsk_is_polling(idle))
++		smp_send_reschedule(cpu);
++}
++
++#endif /* CONFIG_NO_HZ */
++
++/*
++ * 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;
++	int running = 0;
++	int queued = 0;
++	struct rq *rq;
++	int ret = 0;
++
++	rq = task_grq_lock(p, &flags);
++	if (!cpumask_intersects(new_mask, cpu_online_mask)) {
++		ret = -EINVAL;
++		goto out;
++	}
++
++	if (unlikely((p->flags & PF_THREAD_BOUND) && p != current &&
++		     !cpumask_equal(&p->cpus_allowed, new_mask))) {
++		ret = -EINVAL;
++		goto out;
++	}
++
++	queued = task_queued_only(p);
++
++	cpumask_copy(&p->cpus_allowed, new_mask);
++	p->rt.nr_cpus_allowed = cpumask_weight(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;
++
++	/* Reschedule the task, schedule() will know if it can keep running */
++	if (task_running(p))
++		running = 1;
++	else
++		set_task_cpu(p, cpumask_any_and(cpu_online_mask, new_mask));
++
++out:
++	if (queued)
++		try_preempt(p);
++	task_grq_unlock(&flags);
++
++	/* This might be a flaky way of changing cpus! */
++	if (running)
++		schedule();
++	return ret;
++}
++EXPORT_SYMBOL_GPL(set_cpus_allowed_ptr);
++
++#ifdef CONFIG_HOTPLUG_CPU
++/* Schedules idle task to be the next runnable task on current CPU.
++ * It does so by boosting its priority to highest possible.
++ * Used by CPU offline code.
++ */
++void sched_idle_next(void)
++{
++	int this_cpu = smp_processor_id();
++	struct rq *rq = cpu_rq(this_cpu);
++	struct task_struct *idle = rq->idle;
++	unsigned long flags;
++
++	/* cpu has to be offline */
++	BUG_ON(cpu_online(this_cpu));
++
++	/*
++	 * Strictly not necessary since rest of the CPUs are stopped by now
++	 * and interrupts disabled on the current cpu.
++	 */
++	time_grq_lock(rq, &flags);
++
++	__setscheduler(idle, SCHED_FIFO, MAX_RT_PRIO - 1);
++
++	activate_idle_task(idle);
++	set_tsk_need_resched(rq->curr);
++
++	grq_unlock_irqrestore(&flags);
++}
++
++/*
++ * 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);
++}
++
++#endif /* CONFIG_HOTPLUG_CPU */
++
++#if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SYSCTL)
++
++static struct ctl_table sd_ctl_dir[] = {
++	{
++		.procname	= "sched_domain",
++		.mode		= 0555,
++	},
++	{0, },
++};
++
++static struct ctl_table sd_ctl_root[] = {
++	{
++		.ctl_name	= CTL_KERN,
++		.procname	= "kernel",
++		.mode		= 0555,
++		.child		= sd_ctl_dir,
++	},
++	{0, },
++};
++
++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 void
++set_table_entry(struct ctl_table *entry,
++		const char *procname, void *data, int maxlen,
++		mode_t mode, proc_handler *proc_handler)
++{
++	entry->procname = procname;
++	entry->data = data;
++	entry->maxlen = maxlen;
++	entry->mode = mode;
++	entry->proc_handler = proc_handler;
++}
++
++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);
++	set_table_entry(&table[1], "max_interval", &sd->max_interval,
++		sizeof(long), 0644, proc_doulongvec_minmax);
++	set_table_entry(&table[2], "busy_idx", &sd->busy_idx,
++		sizeof(int), 0644, proc_dointvec_minmax);
++	set_table_entry(&table[3], "idle_idx", &sd->idle_idx,
++		sizeof(int), 0644, proc_dointvec_minmax);
++	set_table_entry(&table[4], "newidle_idx", &sd->newidle_idx,
++		sizeof(int), 0644, proc_dointvec_minmax);
++	set_table_entry(&table[5], "wake_idx", &sd->wake_idx,
++		sizeof(int), 0644, proc_dointvec_minmax);
++	set_table_entry(&table[6], "forkexec_idx", &sd->forkexec_idx,
++		sizeof(int), 0644, proc_dointvec_minmax);
++	set_table_entry(&table[7], "busy_factor", &sd->busy_factor,
++		sizeof(int), 0644, proc_dointvec_minmax);
++	set_table_entry(&table[8], "imbalance_pct", &sd->imbalance_pct,
++		sizeof(int), 0644, proc_dointvec_minmax);
++	set_table_entry(&table[9], "cache_nice_tries",
++		&sd->cache_nice_tries,
++		sizeof(int), 0644, proc_dointvec_minmax);
++	set_table_entry(&table[10], "flags", &sd->flags,
++		sizeof(int), 0644, proc_dointvec_minmax);
++	set_table_entry(&table[11], "name", sd->name,
++		CORENAME_MAX_SIZE, 0444, proc_dostring);
++	/* &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_online_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_online_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) {
++		cpumask_set_cpu(rq->cpu, rq->rd->online);
++		rq->online = 1;
++	}
++}
++
++static void set_rq_offline(struct rq *rq)
++{
++	if (rq->online) {
++		cpumask_clear_cpu(rq->cpu, rq->rd->online);
++		rq->online = 0;
++	}
++}
++
++#ifdef CONFIG_HOTPLUG_CPU
++/*
++ * This cpu is going down, so walk over the tasklist and find tasks that can
++ * only run on this cpu and remove their affinity. Store their value in
++ * unplugged_mask so it can be restored once their correct cpu is online. No
++ * need to do anything special since they'll just move on next reschedule if
++ * they're running.
++ */
++static void remove_cpu(unsigned long cpu)
++{
++	struct task_struct *p, *t;
++
++	read_lock(&tasklist_lock);
++
++	do_each_thread(t, p) {
++		cpumask_t cpus_remaining;
++
++		cpus_and(cpus_remaining, p->cpus_allowed, cpu_online_map);
++		cpu_clear(cpu, cpus_remaining);
++		if (cpus_empty(cpus_remaining)) {
++			p->unplugged_mask = p->cpus_allowed;
++			p->cpus_allowed = cpu_possible_map;
++		}
++	} while_each_thread(t, p);
++
++	read_unlock(&tasklist_lock);
++}
++
++/*
++ * This cpu is coming up so add it to the cpus_allowed.
++ */
++static void add_cpu(unsigned long cpu)
++{
++	struct task_struct *p, *t;
++
++	read_lock(&tasklist_lock);
++
++	do_each_thread(t, p) {
++		/* Have we taken all the cpus from the unplugged_mask back */
++		if (cpus_empty(p->unplugged_mask))
++			continue;
++
++		/* Was this cpu in the unplugged_mask mask */
++		if (cpu_isset(cpu, p->unplugged_mask)) {
++			cpu_set(cpu, p->cpus_allowed);
++			if (cpus_subset(p->unplugged_mask, p->cpus_allowed)) {
++				/*
++				 * Have we set more than the unplugged_mask?
++				 * If so, that means we have remnants set from
++				 * the unplug/plug cycle and need to remove
++				 * them. Then clear the unplugged_mask as we've
++				 * set all the cpus back.
++				 */
++				p->cpus_allowed = p->unplugged_mask;
++				cpus_clear(p->unplugged_mask);
++			}
++		}
++	} while_each_thread(t, p);
++
++	read_unlock(&tasklist_lock);
++}
++#else
++static void add_cpu(unsigned long cpu)
++{
++}
++#endif
++
++/*
++ * migration_call - callback that gets triggered when a CPU is added.
++ */
++static int __cpuinit
++migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
++{
++	int cpu = (long)hcpu;
++	unsigned long flags;
++	struct rq *rq;
++
++	switch (action) {
++
++	case CPU_UP_PREPARE:
++	case CPU_UP_PREPARE_FROZEN:
++		break;
++
++	case CPU_ONLINE:
++	case CPU_ONLINE_FROZEN:
++		/* Update our root-domain */
++		rq = cpu_rq(cpu);
++		grq_lock_irqsave(&flags);
++		if (rq->rd) {
++			BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span));
++
++			set_rq_online(rq);
++		}
++		add_cpu(cpu);
++		grq_unlock_irqrestore(&flags);
++		break;
++
++#ifdef CONFIG_HOTPLUG_CPU
++	case CPU_UP_CANCELED:
++	case CPU_UP_CANCELED_FROZEN:
++		break;
++
++	case CPU_DEAD:
++	case CPU_DEAD_FROZEN:
++		cpuset_lock(); /* around calls to cpuset_cpus_allowed_lock() */
++		rq = cpu_rq(cpu);
++		/* Idle task back to normal (off runqueue, low prio) */
++		grq_lock_irq();
++		remove_cpu(cpu);
++		deactivate_task(rq->idle);
++		rq->idle->static_prio = MAX_PRIO;
++		__setscheduler(rq->idle, SCHED_NORMAL, 0);
++		rq->idle->prio = PRIO_LIMIT;
++		update_rq_clock(rq);
++		grq_unlock_irq();
++		cpuset_unlock();
++		break;
++
++	case CPU_DYING:
++	case CPU_DYING_FROZEN:
++		rq = cpu_rq(cpu);
++		grq_lock_irqsave(&flags);
++		if (rq->rd) {
++			BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span));
++			set_rq_offline(rq);
++		}
++		grq_unlock_irqrestore(&flags);
++		break;
++#endif
++	}
++	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_counter subsystem, though.
++ */
++static struct notifier_block __cpuinitdata migration_notifier = {
++	.notifier_call = migration_call,
++	.priority = 10
++};
++
++int __init migration_init(void)
++{
++	void *cpu = (void *)(long)smp_processor_id();
++	int err;
++
++	/* Start one 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);
++
++	return 0;
++}
++early_initcall(migration_init);
++#endif
++
++/*
++ * sched_domains_mutex serializes calls to arch_init_sched_domains,
++ * detach_destroy_domains and partition_sched_domains.
++ */
++static DEFINE_MUTEX(sched_domains_mutex);
++
++#ifdef CONFIG_SMP
++
++#ifdef CONFIG_SCHED_DEBUG
++
++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;
++		}
++
++		if (!group->__cpu_power) {
++			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 (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->__cpu_power != SCHED_LOAD_SCALE) {
++			printk(KERN_CONT " (__cpu_power = %d)",
++				group->__cpu_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)
++{
++	cpumask_var_t groupmask;
++	int level = 0;
++
++	if (!sd) {
++		printk(KERN_DEBUG "CPU%d attaching NULL sched-domain.\n", cpu);
++		return;
++	}
++
++	printk(KERN_DEBUG "CPU%d attaching sched-domain:\n", cpu);
++
++	if (!alloc_cpumask_var(&groupmask, GFP_KERNEL)) {
++		printk(KERN_DEBUG "Cannot load-balance (out of memory)\n");
++		return;
++	}
++
++	for (;;) {
++		if (sched_domain_debug_one(sd, cpu, level, groupmask))
++			break;
++		level++;
++		sd = sd->parent;
++		if (!sd)
++			break;
++	}
++	free_cpumask_var(groupmask);
++}
++#else /* !CONFIG_SCHED_DEBUG */
++# define sched_domain_debug(sd, cpu) do { } while (0)
++#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_IDLE |
++			 SD_WAKE_AFFINE |
++			 SD_WAKE_BALANCE))
++		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;
++
++	/* Does parent contain flags not in child? */
++	/* WAKE_BALANCE is a subset of WAKE_AFFINE */
++	if (cflags & SD_WAKE_AFFINE)
++		pflags &= ~SD_WAKE_BALANCE;
++	/* 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 root_domain *rd)
++{
++	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;
++
++	grq_lock_irqsave(&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_online_mask))
++		set_rq_online(rq);
++
++	grq_unlock_irqrestore(&flags);
++
++	if (old_rd)
++		free_rootdomain(old_rd);
++}
++
++static int init_rootdomain(struct root_domain *rd, bool bootmem)
++{
++	gfp_t gfp = GFP_KERNEL;
++
++	memset(rd, 0, sizeof(*rd));
++
++	if (bootmem)
++		gfp = GFP_NOWAIT;
++
++	if (!alloc_cpumask_var(&rd->span, gfp))
++		goto out;
++	if (!alloc_cpumask_var(&rd->online, gfp))
++		goto free_span;
++	if (!alloc_cpumask_var(&rd->rto_mask, gfp))
++		goto free_online;
++
++	return 0;
++
++free_online:
++	free_cpumask_var(rd->online);
++free_span:
++	free_cpumask_var(rd->span);
++out:
++	return -ENOMEM;
++}
++
++static void init_defrootdomain(void)
++{
++	init_rootdomain(&def_root_domain, true);
++
++	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, false) != 0) {
++		kfree(rd);
++		return NULL;
++	}
++
++	return rd;
++}
++
++/*
++ * 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;
++		} else
++			tmp = tmp->parent;
++	}
++
++	if (sd && sd_degenerate(sd)) {
++		sd = sd->parent;
++		if (sd)
++			sd->child = NULL;
++	}
++
++	sched_domain_debug(sd, cpu);
++
++	rq_attach_root(rq, rd);
++	rcu_assign_pointer(rq->sd, sd);
++}
++
++/* 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)
++{
++	cpulist_parse(str, cpu_isolated_map);
++	return 1;
++}
++
++__setup("isolcpus=", isolated_cpu_setup);
++
++/*
++ * init_sched_build_groups takes the cpumask we wish to span, and a pointer
++ * to a function which identifies what group(along with sched group) a CPU
++ * belongs to. The return value of group_fn must be a >= 0 and < nr_cpu_ids
++ * (due to the fact that we keep track of groups covered with a struct cpumask).
++ *
++ * init_sched_build_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.
++ */
++static void
++init_sched_build_groups(const struct cpumask *span,
++			const struct cpumask *cpu_map,
++			int (*group_fn)(int cpu, const struct cpumask *cpu_map,
++					struct sched_group **sg,
++					struct cpumask *tmpmask),
++			struct cpumask *covered, struct cpumask *tmpmask)
++{
++	struct sched_group *first = NULL, *last = NULL;
++	int i;
++
++	cpumask_clear(covered);
++
++	for_each_cpu(i, span) {
++		struct sched_group *sg;
++		int group = group_fn(i, cpu_map, &sg, tmpmask);
++		int j;
++
++		if (cpumask_test_cpu(i, covered))
++			continue;
++
++		cpumask_clear(sched_group_cpus(sg));
++		sg->__cpu_power = 0;
++
++		for_each_cpu(j, span) {
++			if (group_fn(j, cpu_map, NULL, tmpmask) != 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;
++}
++
++#define SD_NODES_PER_DOMAIN 16
++
++#ifdef CONFIG_NUMA
++
++/**
++ * find_next_best_node - find the next node to include in a sched_domain
++ * @node: node whose sched_domain we're building
++ * @used_nodes: nodes already in the sched_domain
++ *
++ * Find the next node to include in a given scheduling domain. Simply
++ * finds the closest node not already in the @used_nodes map.
++ *
++ * Should use nodemask_t.
++ */
++static int find_next_best_node(int node, nodemask_t *used_nodes)
++{
++	int i, n, val, min_val, best_node = 0;
++
++	min_val = INT_MAX;
++
++	for (i = 0; i < nr_node_ids; i++) {
++		/* Start at @node */
++		n = (node + i) % nr_node_ids;
++
++		if (!nr_cpus_node(n))
++			continue;
++
++		/* Skip already used nodes */
++		if (node_isset(n, *used_nodes))
++			continue;
++
++		/* Simple min distance search */
++		val = node_distance(node, n);
++
++		if (val < min_val) {
++			min_val = val;
++			best_node = n;
++		}
++	}
++
++	node_set(best_node, *used_nodes);
++	return best_node;
++}
++
++/**
++ * sched_domain_node_span - get a cpumask for a node's sched_domain
++ * @node: node whose cpumask we're constructing
++ * @span: resulting cpumask
++ *
++ * Given a node, construct a good cpumask for its sched_domain to span. It
++ * should be one that prevents unnecessary balancing, but also spreads tasks
++ * out optimally.
++ */
++static void sched_domain_node_span(int node, struct cpumask *span)
++{
++	nodemask_t used_nodes;
++	int i;
++
++	cpumask_clear(span);
++	nodes_clear(used_nodes);
++
++	cpumask_or(span, span, cpumask_of_node(node));
++	node_set(node, used_nodes);
++
++	for (i = 1; i < SD_NODES_PER_DOMAIN; i++) {
++		int next_node = find_next_best_node(node, &used_nodes);
++
++		cpumask_or(span, span, cpumask_of_node(next_node));
++	}
++}
++#endif /* CONFIG_NUMA */
++
++int sched_smt_power_savings = 0, sched_mc_power_savings = 0;
++
++/*
++ * The cpus mask in sched_group and sched_domain hangs off the end.
++ *
++ * ( See the the comments in include/linux/sched.h:struct sched_group
++ *   and struct sched_domain. )
++ */
++struct static_sched_group {
++	struct sched_group sg;
++	DECLARE_BITMAP(cpus, CONFIG_NR_CPUS);
++};
++
++struct static_sched_domain {
++	struct sched_domain sd;
++	DECLARE_BITMAP(span, CONFIG_NR_CPUS);
++};
++
++/*
++ * SMT sched-domains:
++ */
++#ifdef CONFIG_SCHED_SMT
++static DEFINE_PER_CPU(struct static_sched_domain, cpu_domains);
++static DEFINE_PER_CPU(struct static_sched_group, sched_group_cpus);
++
++static int
++cpu_to_cpu_group(int cpu, const struct cpumask *cpu_map,
++		 struct sched_group **sg, struct cpumask *unused)
++{
++	if (sg)
++		*sg = &per_cpu(sched_group_cpus, cpu).sg;
++	return cpu;
++}
++#endif /* CONFIG_SCHED_SMT */
++
++/*
++ * multi-core sched-domains:
++ */
++#ifdef CONFIG_SCHED_MC
++static DEFINE_PER_CPU(struct static_sched_domain, core_domains);
++static DEFINE_PER_CPU(struct static_sched_group, sched_group_core);
++#endif /* CONFIG_SCHED_MC */
++
++#if defined(CONFIG_SCHED_MC) && defined(CONFIG_SCHED_SMT)
++static int
++cpu_to_core_group(int cpu, const struct cpumask *cpu_map,
++		  struct sched_group **sg, struct cpumask *mask)
++{
++	int group;
++
++	cpumask_and(mask, topology_thread_cpumask(cpu), cpu_map);
++	group = cpumask_first(mask);
++	if (sg)
++		*sg = &per_cpu(sched_group_core, group).sg;
++	return group;
++}
++#elif defined(CONFIG_SCHED_MC)
++static int
++cpu_to_core_group(int cpu, const struct cpumask *cpu_map,
++		  struct sched_group **sg, struct cpumask *unused)
++{
++	if (sg)
++		*sg = &per_cpu(sched_group_core, cpu).sg;
++	return cpu;
++}
++#endif
++
++static DEFINE_PER_CPU(struct static_sched_domain, phys_domains);
++static DEFINE_PER_CPU(struct static_sched_group, sched_group_phys);
++
++static int
++cpu_to_phys_group(int cpu, const struct cpumask *cpu_map,
++		  struct sched_group **sg, struct cpumask *mask)
++{
++	int group;
++#ifdef CONFIG_SCHED_MC
++	cpumask_and(mask, cpu_coregroup_mask(cpu), cpu_map);
++	group = cpumask_first(mask);
++#elif defined(CONFIG_SCHED_SMT)
++	cpumask_and(mask, topology_thread_cpumask(cpu), cpu_map);
++	group = cpumask_first(mask);
++#else
++	group = cpu;
++#endif
++	if (sg)
++		*sg = &per_cpu(sched_group_phys, group).sg;
++	return group;
++}
++
++/**
++ * group_first_cpu - Returns the first cpu in the cpumask of a sched_group.
++ * @group: The group whose first cpu is to be returned.
++ */
++static inline unsigned int group_first_cpu(struct sched_group *group)
++{
++	return cpumask_first(sched_group_cpus(group));
++}
++
++#ifdef CONFIG_NUMA
++/*
++ * The init_sched_build_groups can't handle what we want to do with node
++ * groups, so roll our own. Now each node has its own list of groups which
++ * gets dynamically allocated.
++ */
++static DEFINE_PER_CPU(struct static_sched_domain, node_domains);
++static struct sched_group ***sched_group_nodes_bycpu;
++
++static DEFINE_PER_CPU(struct static_sched_domain, allnodes_domains);
++static DEFINE_PER_CPU(struct static_sched_group, sched_group_allnodes);
++
++static int cpu_to_allnodes_group(int cpu, const struct cpumask *cpu_map,
++				 struct sched_group **sg,
++				 struct cpumask *nodemask)
++{
++	int group;
++
++	cpumask_and(nodemask, cpumask_of_node(cpu_to_node(cpu)), cpu_map);
++	group = cpumask_first(nodemask);
++
++	if (sg)
++		*sg = &per_cpu(sched_group_allnodes, group).sg;
++	return group;
++}
++
++static void init_numa_sched_groups_power(struct sched_group *group_head)
++{
++	struct sched_group *sg = group_head;
++	int j;
++
++	if (!sg)
++		return;
++	do {
++		for_each_cpu(j, sched_group_cpus(sg)) {
++			struct sched_domain *sd;
++
++			sd = &per_cpu(phys_domains, j).sd;
++			if (j != group_first_cpu(sd->groups)) {
++				/*
++				 * Only add "power" once for each
++				 * physical package.
++				 */
++				continue;
++			}
++
++			sg_inc_cpu_power(sg, sd->groups->__cpu_power);
++		}
++		sg = sg->next;
++	} while (sg != group_head);
++}
++#endif /* CONFIG_NUMA */
++
++#ifdef CONFIG_NUMA
++/* Free memory allocated for various sched_group structures */
++static void free_sched_groups(const struct cpumask *cpu_map,
++			      struct cpumask *nodemask)
++{
++	int cpu, i;
++
++	for_each_cpu(cpu, cpu_map) {
++		struct sched_group **sched_group_nodes
++			= sched_group_nodes_bycpu[cpu];
++
++		if (!sched_group_nodes)
++			continue;
++
++		for (i = 0; i < nr_node_ids; i++) {
++			struct sched_group *oldsg, *sg = sched_group_nodes[i];
++
++			cpumask_and(nodemask, cpumask_of_node(i), cpu_map);
++			if (cpumask_empty(nodemask))
++				continue;
++
++			if (sg == NULL)
++				continue;
++			sg = sg->next;
++next_sg:
++			oldsg = sg;
++			sg = sg->next;
++			kfree(oldsg);
++			if (oldsg != sched_group_nodes[i])
++				goto next_sg;
++		}
++		kfree(sched_group_nodes);
++		sched_group_nodes_bycpu[cpu] = NULL;
++	}
++}
++#else /* !CONFIG_NUMA */
++static void free_sched_groups(const struct cpumask *cpu_map,
++			      struct cpumask *nodemask)
++{
++}
++#endif /* CONFIG_NUMA */
++
++/*
++ * 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.
++ *
++ * cpu_power will be a multiple of SCHED_LOAD_SCALE. This multiple represents
++ * the maximum number of tasks a group can handle in the presence of other idle
++ * or lightly loaded groups in the same sched domain.
++ */
++static void init_sched_groups_power(int cpu, struct sched_domain *sd)
++{
++	struct sched_domain *child;
++	struct sched_group *group;
++
++	WARN_ON(!sd || !sd->groups);
++
++	if (cpu != group_first_cpu(sd->groups))
++		return;
++
++	child = sd->child;
++
++	sd->groups->__cpu_power = 0;
++
++	/*
++	 * For perf policy, if the groups in child domain share resources
++	 * (for example cores sharing some portions of the cache hierarchy
++	 * or SMT), then set this domain groups cpu_power such that each group
++	 * can handle only one task, when there are other idle groups in the
++	 * same sched domain.
++	 */
++	if (!child || (!(sd->flags & SD_POWERSAVINGS_BALANCE) &&
++		       (child->flags &
++			(SD_SHARE_CPUPOWER | SD_SHARE_PKG_RESOURCES)))) {
++		sg_inc_cpu_power(sd->groups, SCHED_LOAD_SCALE);
++		return;
++	}
++
++	/*
++	 * add cpu_power of each child group to this groups cpu_power
++	 */
++	group = child->groups;
++	do {
++		sg_inc_cpu_power(sd->groups, group->__cpu_power);
++		group = group->next;
++	} while (group != child->groups);
++}
++
++/*
++ * 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(sd, type)	sd_init_##type(sd)
++
++#define SD_INIT_FUNC(type)	\
++static noinline void sd_init_##type(struct sched_domain *sd)	\
++{								\
++	memset(sd, 0, sizeof(*sd));				\
++	*sd = SD_##type##_INIT;					\
++	sd->level = SD_LV_##type;				\
++	SD_INIT_NAME(sd, type);					\
++}
++
++SD_INIT_FUNC(CPU)
++#ifdef CONFIG_NUMA
++ SD_INIT_FUNC(ALLNODES)
++ SD_INIT_FUNC(NODE)
++#endif
++#ifdef CONFIG_SCHED_SMT
++ SD_INIT_FUNC(SIBLING)
++#endif
++#ifdef CONFIG_SCHED_MC
++ SD_INIT_FUNC(MC)
++#endif
++
++static int default_relax_domain_level = -1;
++
++static int __init setup_relax_domain_level(char *str)
++{
++	unsigned long val;
++
++	val = simple_strtoul(str, NULL, 0);
++	if (val < SD_LV_MAX)
++		default_relax_domain_level = val;
++
++	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_WAKE_IDLE|SD_BALANCE_NEWIDLE);
++	} else {
++		/* turn on idle balance on this domain */
++		sd->flags |= (SD_WAKE_IDLE_FAR|SD_BALANCE_NEWIDLE);
++	}
++}
++
++/*
++ * 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)
++{
++	int i, err = -ENOMEM;
++	struct root_domain *rd;
++	cpumask_var_t nodemask, this_sibling_map, this_core_map, send_covered,
++		tmpmask;
++#ifdef CONFIG_NUMA
++	cpumask_var_t domainspan, covered, notcovered;
++	struct sched_group **sched_group_nodes = NULL;
++	int sd_allnodes = 0;
++
++	if (!alloc_cpumask_var(&domainspan, GFP_KERNEL))
++		goto out;
++	if (!alloc_cpumask_var(&covered, GFP_KERNEL))
++		goto free_domainspan;
++	if (!alloc_cpumask_var(&notcovered, GFP_KERNEL))
++		goto free_covered;
++#endif
++
++	if (!alloc_cpumask_var(&nodemask, GFP_KERNEL))
++		goto free_notcovered;
++	if (!alloc_cpumask_var(&this_sibling_map, GFP_KERNEL))
++		goto free_nodemask;
++	if (!alloc_cpumask_var(&this_core_map, GFP_KERNEL))
++		goto free_this_sibling_map;
++	if (!alloc_cpumask_var(&send_covered, GFP_KERNEL))
++		goto free_this_core_map;
++	if (!alloc_cpumask_var(&tmpmask, GFP_KERNEL))
++		goto free_send_covered;
++
++#ifdef CONFIG_NUMA
++	/*
++	 * Allocate the per-node list of sched groups
++	 */
++	sched_group_nodes = kcalloc(nr_node_ids, sizeof(struct sched_group *),
++				    GFP_KERNEL);
++	if (!sched_group_nodes) {
++		printk(KERN_WARNING "Can not alloc sched group node list\n");
++		goto free_tmpmask;
++	}
++#endif
++
++	rd = alloc_rootdomain();
++	if (!rd) {
++		printk(KERN_WARNING "Cannot alloc root domain\n");
++		goto free_sched_groups;
++	}
++
++#ifdef CONFIG_NUMA
++	sched_group_nodes_bycpu[cpumask_first(cpu_map)] = sched_group_nodes;
++#endif
++
++	/*
++	 * Set up domains for cpus specified by the cpu_map.
++	 */
++	for_each_cpu(i, cpu_map) {
++		struct sched_domain *sd = NULL, *p;
++
++		cpumask_and(nodemask, cpumask_of_node(cpu_to_node(i)), cpu_map);
++
++#ifdef CONFIG_NUMA
++		if (cpumask_weight(cpu_map) >
++				SD_NODES_PER_DOMAIN*cpumask_weight(nodemask)) {
++			sd = &per_cpu(allnodes_domains, i).sd;
++			SD_INIT(sd, ALLNODES);
++			set_domain_attribute(sd, attr);
++			cpumask_copy(sched_domain_span(sd), cpu_map);
++			cpu_to_allnodes_group(i, cpu_map, &sd->groups, tmpmask);
++			p = sd;
++			sd_allnodes = 1;
++		} else
++			p = NULL;
++
++		sd = &per_cpu(node_domains, i).sd;
++		SD_INIT(sd, NODE);
++		set_domain_attribute(sd, attr);
++		sched_domain_node_span(cpu_to_node(i), sched_domain_span(sd));
++		sd->parent = p;
++		if (p)
++			p->child = sd;
++		cpumask_and(sched_domain_span(sd),
++			    sched_domain_span(sd), cpu_map);
++#endif
++
++		p = sd;
++		sd = &per_cpu(phys_domains, i).sd;
++		SD_INIT(sd, CPU);
++		set_domain_attribute(sd, attr);
++		cpumask_copy(sched_domain_span(sd), nodemask);
++		sd->parent = p;
++		if (p)
++			p->child = sd;
++		cpu_to_phys_group(i, cpu_map, &sd->groups, tmpmask);
++
++#ifdef CONFIG_SCHED_MC
++		p = sd;
++		sd = &per_cpu(core_domains, i).sd;
++		SD_INIT(sd, MC);
++		set_domain_attribute(sd, attr);
++		cpumask_and(sched_domain_span(sd), cpu_map,
++						   cpu_coregroup_mask(i));
++		sd->parent = p;
++		p->child = sd;
++		cpu_to_core_group(i, cpu_map, &sd->groups, tmpmask);
++#endif
++
++#ifdef CONFIG_SCHED_SMT
++		p = sd;
++		sd = &per_cpu(cpu_domains, i).sd;
++		SD_INIT(sd, SIBLING);
++		set_domain_attribute(sd, attr);
++		cpumask_and(sched_domain_span(sd),
++			    topology_thread_cpumask(i), cpu_map);
++		sd->parent = p;
++		p->child = sd;
++		cpu_to_cpu_group(i, cpu_map, &sd->groups, tmpmask);
++#endif
++	}
++
++#ifdef CONFIG_SCHED_SMT
++	/* Set up CPU (sibling) groups */
++	for_each_cpu(i, cpu_map) {
++		cpumask_and(this_sibling_map,
++			    topology_thread_cpumask(i), cpu_map);
++		if (i != cpumask_first(this_sibling_map))
++			continue;
++
++		init_sched_build_groups(this_sibling_map, cpu_map,
++					&cpu_to_cpu_group,
++					send_covered, tmpmask);
++	}
++#endif
++
++#ifdef CONFIG_SCHED_MC
++	/* Set up multi-core groups */
++	for_each_cpu(i, cpu_map) {
++		cpumask_and(this_core_map, cpu_coregroup_mask(i), cpu_map);
++		if (i != cpumask_first(this_core_map))
++			continue;
++
++		init_sched_build_groups(this_core_map, cpu_map,
++					&cpu_to_core_group,
++					send_covered, tmpmask);
++	}
++#endif
++
++	/* Set up physical groups */
++	for (i = 0; i < nr_node_ids; i++) {
++		cpumask_and(nodemask, cpumask_of_node(i), cpu_map);
++		if (cpumask_empty(nodemask))
++			continue;
++
++		init_sched_build_groups(nodemask, cpu_map,
++					&cpu_to_phys_group,
++					send_covered, tmpmask);
++	}
++
++#ifdef CONFIG_NUMA
++	/* Set up node groups */
++	if (sd_allnodes) {
++		init_sched_build_groups(cpu_map, cpu_map,
++					&cpu_to_allnodes_group,
++					send_covered, tmpmask);
++	}
++
++	for (i = 0; i < nr_node_ids; i++) {
++		/* Set up node groups */
++		struct sched_group *sg, *prev;
++		int j;
++
++		cpumask_clear(covered);
++		cpumask_and(nodemask, cpumask_of_node(i), cpu_map);
++		if (cpumask_empty(nodemask)) {
++			sched_group_nodes[i] = NULL;
++			continue;
++		}
++
++		sched_domain_node_span(i, domainspan);
++		cpumask_and(domainspan, domainspan, cpu_map);
++
++		sg = kmalloc_node(sizeof(struct sched_group) + cpumask_size(),
++				  GFP_KERNEL, i);
++		if (!sg) {
++			printk(KERN_WARNING "Can not alloc domain group for "
++				"node %d\n", i);
++			goto error;
++		}
++		sched_group_nodes[i] = sg;
++		for_each_cpu(j, nodemask) {
++			struct sched_domain *sd;
++
++			sd = &per_cpu(node_domains, j).sd;
++			sd->groups = sg;
++		}
++		sg->__cpu_power = 0;
++		cpumask_copy(sched_group_cpus(sg), nodemask);
++		sg->next = sg;
++		cpumask_or(covered, covered, nodemask);
++		prev = sg;
++
++		for (j = 0; j < nr_node_ids; j++) {
++			int n = (i + j) % nr_node_ids;
++
++			cpumask_complement(notcovered, covered);
++			cpumask_and(tmpmask, notcovered, cpu_map);
++			cpumask_and(tmpmask, tmpmask, domainspan);
++			if (cpumask_empty(tmpmask))
++				break;
++
++			cpumask_and(tmpmask, tmpmask, cpumask_of_node(n));
++			if (cpumask_empty(tmpmask))
++				continue;
++
++			sg = kmalloc_node(sizeof(struct sched_group) +
++					  cpumask_size(),
++					  GFP_KERNEL, i);
++			if (!sg) {
++				printk(KERN_WARNING
++				"Can not alloc domain group for node %d\n", j);
++				goto error;
++			}
++			sg->__cpu_power = 0;
++			cpumask_copy(sched_group_cpus(sg), tmpmask);
++			sg->next = prev->next;
++			cpumask_or(covered, covered, tmpmask);
++			prev->next = sg;
++			prev = sg;
++		}
++	}
++#endif
++
++	/* Calculate CPU power for physical packages and nodes */
++#ifdef CONFIG_SCHED_SMT
++	for_each_cpu(i, cpu_map) {
++		struct sched_domain *sd = &per_cpu(cpu_domains, i).sd;
++
++		init_sched_groups_power(i, sd);
++	}
++#endif
++#ifdef CONFIG_SCHED_MC
++	for_each_cpu(i, cpu_map) {
++		struct sched_domain *sd = &per_cpu(core_domains, i).sd;
++
++		init_sched_groups_power(i, sd);
++	}
++#endif
++
++	for_each_cpu(i, cpu_map) {
++		struct sched_domain *sd = &per_cpu(phys_domains, i).sd;
++
++		init_sched_groups_power(i, sd);
++	}
++
++#ifdef CONFIG_NUMA
++	for (i = 0; i < nr_node_ids; i++)
++		init_numa_sched_groups_power(sched_group_nodes[i]);
++
++	if (sd_allnodes) {
++		struct sched_group *sg;
++
++		cpu_to_allnodes_group(cpumask_first(cpu_map), cpu_map, &sg,
++								tmpmask);
++		init_numa_sched_groups_power(sg);
++	}
++#endif
++
++	/* Attach the domains */
++	for_each_cpu(i, cpu_map) {
++		struct sched_domain *sd;
++#ifdef CONFIG_SCHED_SMT
++		sd = &per_cpu(cpu_domains, i).sd;
++#elif defined(CONFIG_SCHED_MC)
++		sd = &per_cpu(core_domains, i).sd;
++#else
++		sd = &per_cpu(phys_domains, i).sd;
++#endif
++		cpu_attach_domain(sd, rd, i);
++	}
++
++	err = 0;
++
++free_tmpmask:
++	free_cpumask_var(tmpmask);
++free_send_covered:
++	free_cpumask_var(send_covered);
++free_this_core_map:
++	free_cpumask_var(this_core_map);
++free_this_sibling_map:
++	free_cpumask_var(this_sibling_map);
++free_nodemask:
++	free_cpumask_var(nodemask);
++free_notcovered:
++#ifdef CONFIG_NUMA
++	free_cpumask_var(notcovered);
++free_covered:
++	free_cpumask_var(covered);
++free_domainspan:
++	free_cpumask_var(domainspan);
++out:
++#endif
++	return err;
++
++free_sched_groups:
++#ifdef CONFIG_NUMA
++	kfree(sched_group_nodes);
++#endif
++	goto free_tmpmask;
++
++#ifdef CONFIG_NUMA
++error:
++	free_sched_groups(cpu_map, tmpmask);
++	free_rootdomain(rd);
++	goto free_tmpmask;
++#endif
++}
++
++static int build_sched_domains(const struct cpumask *cpu_map)
++{
++	return __build_sched_domains(cpu_map, NULL);
++}
++
++static struct cpumask *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;
++}
++
++/*
++ * 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 arch_init_sched_domains(const struct cpumask *cpu_map)
++{
++	int err;
++
++	arch_update_cpu_topology();
++	ndoms_cur = 1;
++	doms_cur = kmalloc(cpumask_size(), GFP_KERNEL);
++	if (!doms_cur)
++		doms_cur = fallback_doms;
++	cpumask_andnot(doms_cur, cpu_map, cpu_isolated_map);
++	dattr_cur = NULL;
++	err = build_sched_domains(doms_cur);
++	register_sched_domain_sysctl();
++
++	return err;
++}
++
++static void arch_destroy_sched_domains(const struct cpumask *cpu_map,
++				       struct cpumask *tmpmask)
++{
++	free_sched_groups(cpu_map, tmpmask);
++}
++
++/*
++ * 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)
++{
++	/* Save because hotplug lock held. */
++	static DECLARE_BITMAP(tmpmask, CONFIG_NR_CPUS);
++	int i;
++
++	for_each_cpu(i, cpu_map)
++		cpu_attach_domain(NULL, &def_root_domain, i);
++	synchronize_sched();
++	arch_destroy_sched_domains(cpu_map, to_cpumask(tmpmask));
++}
++
++/* 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'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 kmalloc'd. This routine takes
++ * ownership of it and will kfree it when done with it. If the caller
++ * failed the kmalloc 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
++ */
++/* FIXME: Change to struct cpumask *doms_new[] */
++void partition_sched_domains(int ndoms_new, struct cpumask *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_online_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)
++		kfree(doms_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);
++}
++
++#if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT)
++static void arch_reinit_sched_domains(void)
++{
++	get_online_cpus();
++
++	/* Destroy domains first to force the rebuild */
++	partition_sched_domains(0, NULL, NULL);
++
++	rebuild_sched_domains();
++	put_online_cpus();
++}
++
++static ssize_t sched_power_savings_store(const char *buf, size_t count, int smt)
++{
++	unsigned int level = 0;
++
++	if (sscanf(buf, "%u", &level) != 1)
++		return -EINVAL;
++
++	/*
++	 * level is always be positive so don't check for
++	 * level < POWERSAVINGS_BALANCE_NONE which is 0
++	 * What happens on 0 or 1 byte write,
++	 * need to check for count as well?
++	 */
++
++	if (level >= MAX_POWERSAVINGS_BALANCE_LEVELS)
++		return -EINVAL;
++
++	if (smt)
++		sched_smt_power_savings = level;
++	else
++		sched_mc_power_savings = level;
++
++	arch_reinit_sched_domains();
++
++	return count;
++}
++
++#ifdef CONFIG_SCHED_MC
++static ssize_t sched_mc_power_savings_show(struct sysdev_class *class,
++					   char *page)
++{
++	return sprintf(page, "%u\n", sched_mc_power_savings);
++}
++static ssize_t sched_mc_power_savings_store(struct sysdev_class *class,
++					    const char *buf, size_t count)
++{
++	return sched_power_savings_store(buf, count, 0);
++}
++static SYSDEV_CLASS_ATTR(sched_mc_power_savings, 0644,
++			 sched_mc_power_savings_show,
++			 sched_mc_power_savings_store);
++#endif
++
++#ifdef CONFIG_SCHED_SMT
++static ssize_t sched_smt_power_savings_show(struct sysdev_class *dev,
++					    char *page)
++{
++	return sprintf(page, "%u\n", sched_smt_power_savings);
++}
++static ssize_t sched_smt_power_savings_store(struct sysdev_class *dev,
++					     const char *buf, size_t count)
++{
++	return sched_power_savings_store(buf, count, 1);
++}
++static SYSDEV_CLASS_ATTR(sched_smt_power_savings, 0644,
++		   sched_smt_power_savings_show,
++		   sched_smt_power_savings_store);
++#endif
++
++int __init sched_create_sysfs_power_savings_entries(struct sysdev_class *cls)
++{
++	int err = 0;
++
++#ifdef CONFIG_SCHED_SMT
++	if (smt_capable())
++		err = sysfs_create_file(&cls->kset.kobj,
++					&attr_sched_smt_power_savings.attr);
++#endif
++#ifdef CONFIG_SCHED_MC
++	if (!err && mc_capable())
++		err = sysfs_create_file(&cls->kset.kobj,
++					&attr_sched_mc_power_savings.attr);
++#endif
++	return err;
++}
++#endif /* CONFIG_SCHED_MC || CONFIG_SCHED_SMT */
++
++#ifndef CONFIG_CPUSETS
++/*
++ * Add online and remove offline CPUs from the scheduler domains.
++ * When cpusets are enabled they take over this function.
++ */
++static int update_sched_domains(struct notifier_block *nfb,
++				unsigned long action, void *hcpu)
++{
++	switch (action) {
++	case CPU_ONLINE:
++	case CPU_ONLINE_FROZEN:
++	case CPU_DEAD:
++	case CPU_DEAD_FROZEN:
++		partition_sched_domains(1, NULL, NULL);
++		return NOTIFY_OK;
++
++	default:
++		return NOTIFY_DONE;
++	}
++}
++#endif
++
++static int update_runtime(struct notifier_block *nfb,
++				unsigned long action, void *hcpu)
++{
++	switch (action) {
++	case CPU_DOWN_PREPARE:
++	case CPU_DOWN_PREPARE_FROZEN:
++		return NOTIFY_OK;
++
++	case CPU_DOWN_FAILED:
++	case CPU_DOWN_FAILED_FROZEN:
++	case CPU_ONLINE:
++	case CPU_ONLINE_FROZEN:
++		return NOTIFY_OK;
++
++	default:
++		return NOTIFY_DONE;
++	}
++}
++
++void __init sched_init_smp(void)
++{
++	cpumask_var_t non_isolated_cpus;
++
++	alloc_cpumask_var(&non_isolated_cpus, GFP_KERNEL);
++
++#if defined(CONFIG_NUMA)
++	sched_group_nodes_bycpu = kzalloc(nr_cpu_ids * sizeof(void **),
++								GFP_KERNEL);
++	BUG_ON(sched_group_nodes_bycpu == NULL);
++#endif
++	get_online_cpus();
++	mutex_lock(&sched_domains_mutex);
++	arch_init_sched_domains(cpu_online_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();
++
++#ifndef CONFIG_CPUSETS
++	/* XXX: Theoretical race here - CPU may be hotplugged now */
++	hotcpu_notifier(update_sched_domains, 0);
++#endif
++
++	/* RT runtime code needs to handle some hotplug events */
++	hotcpu_notifier(update_runtime, 0);
++
++	/* Move init over to a non-isolated CPU */
++	if (set_cpus_allowed_ptr(current, non_isolated_cpus) < 0)
++		BUG();
++	free_cpumask_var(non_isolated_cpus);
++
++	alloc_cpumask_var(&fallback_doms, GFP_KERNEL);
++
++	/*
++	 * Assume that every added cpu gives us slightly less overall latency
++	 * allowing us to increase the base rr_interval, but in a non linear
++	 * fashion.
++	 */
++	rr_interval *= 1 + ilog2(num_online_cpus());
++}
++#else
++void __init sched_init_smp(void)
++{
++}
++#endif /* CONFIG_SMP */
++
++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);
++}
++
++void __init sched_init(void)
++{
++	int i;
++	int highest_cpu = 0;
++
++	prio_ratios[0] = 100;
++	for (i = 1 ; i < PRIO_RANGE ; i++)
++		prio_ratios[i] = prio_ratios[i - 1] * 11 / 10;
++
++#ifdef CONFIG_SMP
++	init_defrootdomain();
++	cpus_clear(grq.cpu_idle_map);
++#endif
++	spin_lock_init(&grq.lock);
++	for_each_possible_cpu(i) {
++		struct rq *rq;
++
++		rq = cpu_rq(i);
++		INIT_LIST_HEAD(&rq->queue);
++		rq->rq_deadline = 0;
++		rq->rq_prio = 0;
++		rq->cpu = i;
++		rq->user_pc = rq->nice_pc = rq->softirq_pc = rq->system_pc =
++			      rq->iowait_pc = rq->idle_pc = 0;
++#ifdef CONFIG_SMP
++		rq->sd = NULL;
++		rq->rd = NULL;
++		rq->online = 0;
++		INIT_LIST_HEAD(&rq->migration_queue);
++		rq_attach_root(rq, &def_root_domain);
++#endif
++		atomic_set(&rq->nr_iowait, 0);
++		highest_cpu = i;
++	}
++	grq.iso_ticks = grq.nr_running = grq.nr_uninterruptible = 0;
++	for (i = 0; i < PRIO_LIMIT; i++)
++		INIT_LIST_HEAD(grq.queue + i);
++	bitmap_zero(grq.prio_bitmap, PRIO_LIMIT);
++	/* delimiter for bitsearch */
++	__set_bit(PRIO_LIMIT, grq.prio_bitmap);
++
++#ifdef CONFIG_SMP
++	nr_cpu_ids = highest_cpu + 1;
++#endif
++
++#ifdef CONFIG_PREEMPT_NOTIFIERS
++	INIT_HLIST_HEAD(&init_task.preempt_notifiers);
++#endif
++
++#ifdef CONFIG_RT_MUTEXES
++	plist_head_init(&init_task.pi_waiters, &init_task.pi_lock);
++#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());
++
++	/* Allocate the nohz_cpu_mask if CONFIG_CPUMASK_OFFSTACK */
++	alloc_cpumask_var(&nohz_cpu_mask, GFP_NOWAIT);
++#ifdef CONFIG_SMP
++#ifdef CONFIG_NO_HZ
++	alloc_cpumask_var(&nohz.cpu_mask, GFP_NOWAIT);
++	alloc_cpumask_var(&nohz.ilb_grp_nohz_mask, GFP_NOWAIT);
++#endif
++	alloc_cpumask_var(&cpu_isolated_map, GFP_NOWAIT);
++#endif /* SMP */
++	perf_counter_init();
++}
++
++#ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
++void __might_sleep(char *file, int line)
++{
++#ifdef in_atomic
++	static unsigned long prev_jiffy;	/* ratelimiting */
++
++	if ((in_atomic() || irqs_disabled()) &&
++	    system_state == SYSTEM_RUNNING && !oops_in_progress) {
++		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("in_atomic():%d, irqs_disabled():%d\n",
++			in_atomic(), irqs_disabled());
++		debug_show_held_locks(current);
++		if (irqs_disabled())
++			print_irqtrace_events(current);
++		dump_stack();
++	}
++#endif
++}
++EXPORT_SYMBOL(__might_sleep);
++#endif
++
++#ifdef CONFIG_MAGIC_SYSRQ
++void normalize_rt_tasks(void)
++{
++	struct task_struct *g, *p;
++	unsigned long flags;
++	struct rq *rq;
++	int queued;
++
++	read_lock_irq(&tasklist_lock);
++
++	do_each_thread(g, p) {
++		if (!rt_task(p) && !iso_task(p))
++			continue;
++
++		spin_lock_irqsave(&p->pi_lock, flags);
++		rq = __task_grq_lock(p);
++		update_rq_clock(rq);
++
++		queued = task_queued_only(p);
++		if (queued)
++			dequeue_task(p);
++		__setscheduler(p, SCHED_NORMAL, 0);
++		if (task_running(p))
++			resched_task(p);
++		if (queued) {
++			enqueue_task(p);
++			try_preempt(p);
++		}
++
++		__task_grq_unlock();
++		spin_unlock_irqrestore(&p->pi_lock, flags);
++	} while_each_thread(g, p);
++
++	read_unlock_irq(&tasklist_lock);
++}
++#endif /* CONFIG_MAGIC_SYSRQ */
++
++#ifdef CONFIG_IA64
++/*
++ * These functions are only useful for the IA64 MCA handling.
++ *
++ * 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);
++}
++
++/**
++ * 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
++
++/*
++ * Use precise platform statistics if available:
++ */
++#ifdef CONFIG_VIRT_CPU_ACCOUNTING
++cputime_t task_utime(struct task_struct *p)
++{
++	return p->utime;
++}
++
++cputime_t task_stime(struct task_struct *p)
++{
++	return p->stime;
++}
++#else
++cputime_t task_utime(struct task_struct *p)
++{
++	clock_t utime = cputime_to_clock_t(p->utime),
++		total = utime + cputime_to_clock_t(p->stime);
++	u64 temp;
++
++	temp = (u64)nsec_to_clock_t(p->se.sum_exec_runtime);
++
++	if (total) {
++		temp *= utime;
++		do_div(temp, total);
++	}
++	utime = (clock_t)temp;
++
++	p->prev_utime = max(p->prev_utime, clock_t_to_cputime(utime));
++	return p->prev_utime;
++}
++
++cputime_t task_stime(struct task_struct *p)
++{
++	clock_t stime;
++
++	stime = nsec_to_clock_t(p->se.sum_exec_runtime) -
++			cputime_to_clock_t(task_utime(p));
++
++	if (stime >= 0)
++		p->prev_stime = max(p->prev_stime, clock_t_to_cputime(stime));
++
++	return p->prev_stime;
++}
++#endif
++
++inline cputime_t task_gtime(struct task_struct *p)
++{
++	return p->gtime;
++}
++
++void __cpuinit init_idle_bootup_task(struct task_struct *idle)
++{}
++
++#ifdef CONFIG_SCHED_DEBUG
++void proc_sched_show_task(struct task_struct *p, struct seq_file *m)
++{}
++
++void proc_sched_set_task(struct task_struct *p)
++{}
++#endif
+--- a/kernel/sysctl.c
++++ b/kernel/sysctl.c
+@@ -86,6 +86,8 @@ extern int percpu_pagelist_fraction;
+ extern int compat_log;
+ extern int latencytop_enabled;
+ extern int sysctl_nr_open_min, sysctl_nr_open_max;
++extern int rr_interval;
++extern int sched_iso_cpu;
+ #ifndef CONFIG_MMU
+ extern int sysctl_nr_trim_pages;
+ #endif
+@@ -103,7 +105,8 @@ static int zero;
+ static int __maybe_unused one = 1;
+ static int __maybe_unused two = 2;
+ static unsigned long one_ul = 1;
+-static int one_hundred = 100;
++static int __read_mostly one_hundred = 100;
++static int __maybe_unused __read_mostly five_thousand = 5000;
+ 
+ /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
+ static unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
+@@ -238,7 +241,7 @@ static struct ctl_table root_table[] = {
+ 	{ .ctl_name = 0 }
+ };
+ 
+-#ifdef CONFIG_SCHED_DEBUG
++#if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SCHED_CFS)
+ static int min_sched_granularity_ns = 100000;		/* 100 usecs */
+ static int max_sched_granularity_ns = NSEC_PER_SEC;	/* 1 second */
+ static int min_wakeup_granularity_ns;			/* 0 usecs */
+@@ -246,7 +249,7 @@ static int max_wakeup_granularity_ns = N
+ #endif
+ 
+ static struct ctl_table kern_table[] = {
+-#ifdef CONFIG_SCHED_DEBUG
++#if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SCHED_CFS)
+ 	{
+ 		.ctl_name	= CTL_UNNUMBERED,
+ 		.procname	= "sched_min_granularity_ns",
+@@ -342,6 +345,7 @@ static struct ctl_table kern_table[] = {
+ 		.extra2		= &one,
+ 	},
+ #endif
++#ifdef CONFIG_SCHED_CFS
+ 	{
+ 		.ctl_name	= CTL_UNNUMBERED,
+ 		.procname	= "sched_rt_period_us",
+@@ -366,6 +370,7 @@ static struct ctl_table kern_table[] = {
+ 		.mode		= 0644,
+ 		.proc_handler	= &proc_dointvec,
+ 	},
++#endif
+ #ifdef CONFIG_PROVE_LOCKING
+ 	{
+ 		.ctl_name	= CTL_UNNUMBERED,
+@@ -798,6 +803,30 @@ static struct ctl_table kern_table[] = {
+ 		.proc_handler	= &proc_dointvec,
+ 	},
+ #endif
++#ifdef CONFIG_SCHED_BFS
++	{
++		.ctl_name	= CTL_UNNUMBERED,
++		.procname	= "rr_interval",
++		.data		= &rr_interval,
++		.maxlen		= sizeof (int),
++		.mode		= 0644,
++		.proc_handler	= &proc_dointvec_minmax,
++		.strategy	= &sysctl_intvec,
++		.extra1		= &one,
++		.extra2		= &five_thousand,
++	},
++	{
++		.ctl_name	= CTL_UNNUMBERED,
++		.procname	= "iso_cpu",
++		.data		= &sched_iso_cpu,
++		.maxlen		= sizeof (int),
++		.mode		= 0644,
++		.proc_handler	= &proc_dointvec_minmax,
++		.strategy	= &sysctl_intvec,
++		.extra1		= &zero,
++		.extra2		= &one_hundred,
++	},
++#endif
+ #if defined(CONFIG_S390) && defined(CONFIG_SMP)
+ 	{
+ 		.ctl_name	= KERN_SPIN_RETRY,
+--- a/kernel/workqueue.c
++++ b/kernel/workqueue.c
+@@ -317,7 +317,9 @@ static int worker_thread(void *__cwq)
+ 	if (cwq->wq->freezeable)
+ 		set_freezable();
+ 
++#ifdef CONFIG_SCHED_CFS
+ 	set_user_nice(current, -5);
++#endif
+ 
+ 	for (;;) {
+ 		prepare_to_wait(&cwq->more_work, &wait, TASK_INTERRUPTIBLE);