add support for the Brain Fuck Scheduler v230 for 2.6.30 (disabled by default)

[openwrt/svn-archive/archive.git] / target / linux / generic-2.6 / patches-2.6.30 / 270-sched_bfs.patch

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 ]
@@ -48,6 +49,7 @@ 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
@@ -170,6 +172,16 @@ 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
@@ -322,6 +334,19 @@ 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
@@ -119,9 +119,10 @@ 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 {
@@ -1042,10 +1045,13 @@ 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;
 
@@ -1096,6 +1102,7 @@ struct sched_entity {
        /* rq "owned" by this entity/group: */
        struct cfs_rq           *my_q;
 #endif
+#endif
 };
 
 struct sched_rt_entity {
@@ -1123,17 +1130,19 @@ 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: */
@@ -1156,6 +1165,9 @@ 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;
@@ -1446,11 +1458,19 @@ 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)
@@ -1734,7 +1754,7 @@ 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
@@ -435,9 +435,22 @@ 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
@@ -488,6 +501,7 @@ 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 $(CONFIG_SCHED_CFS),sched.o,sched_bfs.o) fork.o exec_domain.o panic.o printk.o \
            cpu.o exit.o itimer.o time.o softirq.o resource.o \
            sysctl.o capability.o ptrace.o timer.o user.o \
            signal.o sys.o kmod.o workqueue.o pid.o \
@@ -103,6 +103,7 @@ ifneq ($(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
@@ -15,7 +15,11 @@
 #include <linux/mutex.h>
 #include <trace/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 +1,6059 @@
+/*
+ *  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();
+}
+
+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
@@ -83,6 +83,8 @@ 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
@@ -100,7 +102,8 @@ 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;
@@ -234,7 +237,7 @@ 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 */
@@ -242,7 +245,7 @@ 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",
@@ -327,6 +330,7 @@ static struct ctl_table kern_table[] = {
                .proc_handler   = &proc_dointvec,
        },
 #endif
+#ifdef CONFIG_SCHED_CFS
        {
                .ctl_name       = CTL_UNNUMBERED,
                .procname       = "sched_rt_period_us",
@@ -351,6 +355,7 @@ static struct ctl_table kern_table[] = {
                .mode           = 0644,
                .proc_handler   = &proc_dointvec,
        },
+#endif
 #ifdef CONFIG_PROVE_LOCKING
        {
                .ctl_name       = CTL_UNNUMBERED,
@@ -756,6 +761,30 @@ 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
@@ -320,7 +320,9 @@ 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);
--- /dev/null
+++ b/include/linux/perf_counter.h
@@ -0,0 +1,2 @@
+#define perf_counter_init() do {} while(0)
+#define perf_counter_task_sched_in(...) do {} while(0)
--- /dev/null
+++ b/include/trace/events/sched.h
@@ -0,0 +1 @@
+#include <trace/sched.h>