[git pull] scheduler changes for v2.6.27

!MAILaRCHIVE_VOTE_RePLACE
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To: Linus Torvalds <torvalds@...>
Cc: <linux-kernel@...>, Peter Zijlstra <a.p.zijlstra@...>, Andrew Morton <akpm@...>
Date: Monday, July 14, 2008 - 9:54 am

Linus,

Please pull the latest scheduler git tree from:

   git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip.git sched/for-linus

Thanks,

	Ingo

------------------>
Ankita Garg (1):
      sched: fix accounting in task delay accounting & migration

Arjan van de Ven (1):
      sched: print module list in the "scheduling while atomic" warning

David Rientjes (1):
      sched: prevent bound kthreads from changing cpus_allowed

Dhaval Giani (2):
      sched: add comments for ifdefs in sched.c
      sched: make sched_{rt,fair}.c ifdefs more readable

Dmitry Adamushko (2):
      sched: check for SD_SERIALIZE atomically in rebalance_domains()
      sched: rework of "prioritize non-migratable tasks over migratable ones"

Gautham R Shenoy (2):
      sched: update the sched-domains debug documentation
      sched: print the sd->level in sched_domain_debug code

Gregory Haskins (7):
      sched: prioritize non-migratable tasks over migratable ones
      sched: use a 2-d bitmap for searching lowest-pri CPU
      sched: fix SCHED_OTHER balance iterator to include all tasks
      sched: fix cpupri hotplug support
      sched: fix cpupri priocount
      sched: terminate newidle balancing once at least one task has moved over
      sched: add avg-overlap support to RT tasks

Hiroshi Shimamoto (1):
      sched: fix typo in Documentation/scheduler/sched-rt-group.txt

Ingo Molnar (5):
      namespacecheck: more sched.c fixes
      sched: fix cpuprio build bug
      sched: export cpu_clock
      sched: sched_clock_cpu() based cpu_clock(), lockdep fix
      sched: build fix

Max Krasnyansky (2):
      sched: CPU hotplug events must not destroy scheduler domains created by the cpusets
      sched: Move cpu masks from kernel/sched.c into kernel/cpu.c

Mike Galbraith (2):
      sched: make !hrtick faster
      sched: trivial sched_features cleanup

Paul Mundt (1):
      sched: kill off dead cfs_rq_set_shares()

Peter Zijlstra (34):
      sched: fix hotplug cpus on ia64
      sched: debug: add some rt debug output
      sched: rt: fix SMP bandwidth balancing for throttled groups
      sched: rt: move some code around
      sched: rt: fix the bandwidth contraint computations
      sched: rt: dont stop the period timer when there are tasks wanting to run
      sched: clean up some unused variables
      sched: revert the revert of: weight calculations
      sched: fix calc_delta_asym()
      sched: fix calc_delta_asym, #2
      sched: revert revert of: fair-group: SMP-nice for group scheduling
      sched: sched_clock_cpu() based cpu_clock()
      sched: fix wakeup granularity and buddy granularity
      sched: add full schedstats to /proc/sched_debug
      sched: fix sched_domain aggregation
      sched: update aggregate when holding the RQs
      sched: dont micro manage share losses
      sched: no need to aggregate task_weight
      sched: simplify the group load balancer
      sched: fix newidle smp group balancing
      sched: fix sched_balance_self() smp group balancing
      sched: persistent average load per task
      sched: hierarchical load vs affine wakeups
      sched: hierarchical load vs find_busiest_group
      sched: fix load scaling in group balancing
      sched: fix task_h_load()
      sched: remove prio preference from balance decisions
      sched: optimize effective_load()
      sched: disable source/target_load bias
      sched: fix shares boost logic
      sched: update shares on wakeup
      sched: correct wakeup weight calculations
      sched: incremental effective_load()
      sched: bias effective_load() error towards failing wake_affine().

Rabin Vincent (1):
      sched: fix defined-but-unused warning

Richard Kennedy (1):
      sched: reorder task_struct to reduce padding on 64bit builds

Srivatsa Vaddagiri (2):
      sched: kill task_group balancing
      sched: fix mult overflow

Steven Rostedt (7):
      sched_clock: record from last tick
      sched_clock: widen the max and min time
      sched_clock: stop maximum check on NO HZ
      sched_clock: fix calculation of other CPU
      sched_clock: only update deltas with local reads.
      sched_clock: record TSC after gtod
      sched_clock: and multiplier for TSC to gtod drift

Thomas Gleixner (3):
      namespacecheck: fixes in kernel/sched.c
      sched: fix the cpuprio count really
      sched: move weighted_cpuload into #ifdef CONFIG_SMP section

Vegard Nossum (1):
      sched: fix warning


 Documentation/scheduler/sched-domains.txt  |    7 +-
 Documentation/scheduler/sched-rt-group.txt |    4 +-
 include/linux/sched.h                      |   59 ++--
 kernel/Makefile                            |    5 +-
 kernel/cpu.c                               |   24 +
 kernel/cpuset.c                            |   14 +-
 kernel/kthread.c                           |    1 +
 kernel/sched.c                             |  723 +++++++++++++++++++---------
 kernel/sched_clock.c                       |  137 +++++-
 kernel/sched_cpupri.c                      |  174 +++++++
 kernel/sched_cpupri.h                      |   36 ++
 kernel/sched_debug.c                       |   64 +++-
 kernel/sched_fair.c                        |  413 +++++++++++-----
 kernel/sched_features.h                    |    7 +-
 kernel/sched_rt.c                          |  405 ++++++++++------
 kernel/sched_stats.h                       |   42 ++-
 kernel/sysctl.c                            |    8 +
 kernel/time/tick-sched.c                   |    2 +
 18 files changed, 1555 insertions(+), 570 deletions(-)
 create mode 100644 kernel/sched_cpupri.c
 create mode 100644 kernel/sched_cpupri.h

diff --git a/Documentation/scheduler/sched-domains.txt b/Documentation/scheduler/sched-domains.txt
index a9e990a..373ceac 100644
--- a/Documentation/scheduler/sched-domains.txt
+++ b/Documentation/scheduler/sched-domains.txt
@@ -61,10 +61,7 @@ builder by #define'ing ARCH_HASH_SCHED_DOMAIN, and exporting your
 arch_init_sched_domains function. This function will attach domains to all
 CPUs using cpu_attach_domain.
 
-Implementors should change the line
-#undef SCHED_DOMAIN_DEBUG
-to
-#define SCHED_DOMAIN_DEBUG
-in kernel/sched.c as this enables an error checking parse of the sched domains
+The sched-domains debugging infrastructure can be enabled by enabling
+CONFIG_SCHED_DEBUG. This enables an error checking parse of the sched domains
 which should catch most possible errors (described above). It also prints out
 the domain structure in a visual format.
diff --git a/Documentation/scheduler/sched-rt-group.txt b/Documentation/scheduler/sched-rt-group.txt
index 14f901f..3ef339f 100644
--- a/Documentation/scheduler/sched-rt-group.txt
+++ b/Documentation/scheduler/sched-rt-group.txt
@@ -51,9 +51,9 @@ needs only about 3% CPU time to do so, it can do with a 0.03 * 0.005s =
 0.00015s. So this group can be scheduled with a period of 0.005s and a run time
 of 0.00015s.
 
-The remaining CPU time will be used for user input and other tass. Because
+The remaining CPU time will be used for user input and other tasks. Because
 realtime tasks have explicitly allocated the CPU time they need to perform
-their tasks, buffer underruns in the graphocs or audio can be eliminated.
+their tasks, buffer underruns in the graphics or audio can be eliminated.
 
 NOTE: the above example is not fully implemented as of yet (2.6.25). We still
 lack an EDF scheduler to make non-uniform periods usable.
diff --git a/include/linux/sched.h b/include/linux/sched.h
index c5d3f84..f6cd60f 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -134,7 +134,6 @@ extern unsigned long nr_running(void);
 extern unsigned long nr_uninterruptible(void);
 extern unsigned long nr_active(void);
 extern unsigned long nr_iowait(void);
-extern unsigned long weighted_cpuload(const int cpu);
 
 struct seq_file;
 struct cfs_rq;
@@ -784,6 +783,8 @@ struct sched_domain {
 	unsigned int balance_interval;	/* initialise to 1. units in ms. */
 	unsigned int nr_balance_failed; /* initialise to 0 */
 
+	u64 last_update;
+
 #ifdef CONFIG_SCHEDSTATS
 	/* load_balance() stats */
 	unsigned int lb_count[CPU_MAX_IDLE_TYPES];
@@ -823,23 +824,6 @@ extern int arch_reinit_sched_domains(void);
 
 #endif	/* CONFIG_SMP */
 
-/*
- * A runqueue laden with a single nice 0 task scores a weighted_cpuload of
- * SCHED_LOAD_SCALE. This function returns 1 if any cpu is laden with a
- * task of nice 0 or enough lower priority tasks to bring up the
- * weighted_cpuload
- */
-static inline int above_background_load(void)
-{
-	unsigned long cpu;
-
-	for_each_online_cpu(cpu) {
-		if (weighted_cpuload(cpu) >= SCHED_LOAD_SCALE)
-			return 1;
-	}
-	return 0;
-}
-
 struct io_context;			/* See blkdev.h */
 #define NGROUPS_SMALL		32
 #define NGROUPS_PER_BLOCK	((unsigned int)(PAGE_SIZE / sizeof(gid_t)))
@@ -921,8 +905,8 @@ struct sched_class {
 	void (*set_cpus_allowed)(struct task_struct *p,
 				 const cpumask_t *newmask);
 
-	void (*join_domain)(struct rq *rq);
-	void (*leave_domain)(struct rq *rq);
+	void (*rq_online)(struct rq *rq);
+	void (*rq_offline)(struct rq *rq);
 
 	void (*switched_from) (struct rq *this_rq, struct task_struct *task,
 			       int running);
@@ -1039,6 +1023,7 @@ struct task_struct {
 #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;
@@ -1122,7 +1107,6 @@ struct task_struct {
 	int __user *set_child_tid;		/* CLONE_CHILD_SETTID */
 	int __user *clear_child_tid;		/* CLONE_CHILD_CLEARTID */
 
-	unsigned int rt_priority;
 	cputime_t utime, stime, utimescaled, stimescaled;
 	cputime_t gtime;
 	cputime_t prev_utime, prev_stime;
@@ -1141,12 +1125,12 @@ struct task_struct {
 	gid_t gid,egid,sgid,fsgid;
 	struct group_info *group_info;
 	kernel_cap_t   cap_effective, cap_inheritable, cap_permitted, cap_bset;
-	unsigned securebits;
 	struct user_struct *user;
+	unsigned securebits;
 #ifdef CONFIG_KEYS
+	unsigned char jit_keyring;	/* default keyring to attach requested keys to */
 	struct key *request_key_auth;	/* assumed request_key authority */
 	struct key *thread_keyring;	/* keyring private to this thread */
-	unsigned char jit_keyring;	/* default keyring to attach requested keys to */
 #endif
 	char comm[TASK_COMM_LEN]; /* executable name excluding path
 				     - access with [gs]et_task_comm (which lock
@@ -1233,8 +1217,8 @@ struct task_struct {
 # define MAX_LOCK_DEPTH 48UL
 	u64 curr_chain_key;
 	int lockdep_depth;
-	struct held_lock held_locks[MAX_LOCK_DEPTH];
 	unsigned int lockdep_recursion;
+	struct held_lock held_locks[MAX_LOCK_DEPTH];
 #endif
 
 /* journalling filesystem info */
@@ -1262,10 +1246,6 @@ struct task_struct {
 	u64 acct_vm_mem1;	/* accumulated virtual memory usage */
 	cputime_t acct_stimexpd;/* stime since last update */
 #endif
-#ifdef CONFIG_NUMA
-  	struct mempolicy *mempolicy;
-	short il_next;
-#endif
 #ifdef CONFIG_CPUSETS
 	nodemask_t mems_allowed;
 	int cpuset_mems_generation;
@@ -1285,6 +1265,10 @@ struct task_struct {
 	struct list_head pi_state_list;
 	struct futex_pi_state *pi_state_cache;
 #endif
+#ifdef CONFIG_NUMA
+	struct mempolicy *mempolicy;
+	short il_next;
+#endif
 	atomic_t fs_excl;	/* holding fs exclusive resources */
 	struct rcu_head rcu;
 
@@ -1504,6 +1488,7 @@ static inline void put_task_struct(struct task_struct *t)
 #define PF_SWAPWRITE	0x00800000	/* Allowed to write to swap */
 #define PF_SPREAD_PAGE	0x01000000	/* Spread page cache over cpuset */
 #define PF_SPREAD_SLAB	0x02000000	/* Spread some slab caches over cpuset */
+#define PF_THREAD_BOUND	0x04000000	/* Thread bound to specific cpu */
 #define PF_MEMPOLICY	0x10000000	/* Non-default NUMA mempolicy */
 #define PF_MUTEX_TESTER	0x20000000	/* Thread belongs to the rt mutex tester */
 #define PF_FREEZER_SKIP	0x40000000	/* Freezer should not count it as freezeable */
@@ -1573,13 +1558,28 @@ static inline void sched_clock_idle_sleep_event(void)
 static inline void sched_clock_idle_wakeup_event(u64 delta_ns)
 {
 }
-#else
+
+#ifdef CONFIG_NO_HZ
+static inline void sched_clock_tick_stop(int cpu)
+{
+}
+
+static inline void sched_clock_tick_start(int cpu)
+{
+}
+#endif
+
+#else /* CONFIG_HAVE_UNSTABLE_SCHED_CLOCK */
 extern void sched_clock_init(void);
 extern u64 sched_clock_cpu(int cpu);
 extern void sched_clock_tick(void);
 extern void sched_clock_idle_sleep_event(void);
 extern void sched_clock_idle_wakeup_event(u64 delta_ns);
+#ifdef CONFIG_NO_HZ
+extern void sched_clock_tick_stop(int cpu);
+extern void sched_clock_tick_start(int cpu);
 #endif
+#endif /* CONFIG_HAVE_UNSTABLE_SCHED_CLOCK */
 
 /*
  * For kernel-internal use: high-speed (but slightly incorrect) per-cpu
@@ -1622,6 +1622,7 @@ extern unsigned int sysctl_sched_child_runs_first;
 extern unsigned int sysctl_sched_features;
 extern unsigned int sysctl_sched_migration_cost;
 extern unsigned int sysctl_sched_nr_migrate;
+extern unsigned int sysctl_sched_shares_ratelimit;
 
 int sched_nr_latency_handler(struct ctl_table *table, int write,
 		struct file *file, void __user *buffer, size_t *length,
diff --git a/kernel/Makefile b/kernel/Makefile
index 1c9938a..6c55301 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -3,7 +3,7 @@
 #
 
 obj-y     = sched.o fork.o exec_domain.o panic.o printk.o profile.o \
-	    exit.o itimer.o time.o softirq.o resource.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 \
 	    rcupdate.o extable.o params.o posix-timers.o \
@@ -27,7 +27,7 @@ obj-$(CONFIG_RT_MUTEXES) += rtmutex.o
 obj-$(CONFIG_DEBUG_RT_MUTEXES) += rtmutex-debug.o
 obj-$(CONFIG_RT_MUTEX_TESTER) += rtmutex-tester.o
 obj-$(CONFIG_GENERIC_ISA_DMA) += dma.o
-obj-$(CONFIG_SMP) += cpu.o spinlock.o
+obj-$(CONFIG_SMP) += spinlock.o
 obj-$(CONFIG_DEBUG_SPINLOCK) += spinlock.o
 obj-$(CONFIG_PROVE_LOCKING) += spinlock.o
 obj-$(CONFIG_UID16) += uid16.o
@@ -69,6 +69,7 @@ obj-$(CONFIG_TASK_DELAY_ACCT) += delayacct.o
 obj-$(CONFIG_TASKSTATS) += taskstats.o tsacct.o
 obj-$(CONFIG_MARKERS) += marker.o
 obj-$(CONFIG_LATENCYTOP) += latencytop.o
+obj-$(CONFIG_SMP) += sched_cpupri.o
 
 ifneq ($(CONFIG_SCHED_NO_NO_OMIT_FRAME_POINTER),y)
 # According to Alan Modra <alan@linuxcare.com.au>, the -fno-omit-frame-pointer is
diff --git a/kernel/cpu.c b/kernel/cpu.c
index c77bc3a..b11f06d 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -15,6 +15,28 @@
 #include <linux/stop_machine.h>
 #include <linux/mutex.h>
 
+/*
+ * Represents all cpu's present in the system
+ * In systems capable of hotplug, this map could dynamically grow
+ * as new cpu's are detected in the system via any platform specific
+ * method, such as ACPI for e.g.
+ */
+cpumask_t cpu_present_map __read_mostly;
+EXPORT_SYMBOL(cpu_present_map);
+
+#ifndef CONFIG_SMP
+
+/*
+ * Represents all cpu's that are currently online.
+ */
+cpumask_t cpu_online_map __read_mostly = CPU_MASK_ALL;
+EXPORT_SYMBOL(cpu_online_map);
+
+cpumask_t cpu_possible_map __read_mostly = CPU_MASK_ALL;
+EXPORT_SYMBOL(cpu_possible_map);
+
+#else /* CONFIG_SMP */
+
 /* Serializes the updates to cpu_online_map, cpu_present_map */
 static DEFINE_MUTEX(cpu_add_remove_lock);
 
@@ -403,3 +425,5 @@ out:
 	cpu_maps_update_done();
 }
 #endif /* CONFIG_PM_SLEEP_SMP */
+
+#endif /* CONFIG_SMP */
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 798b3ab..459d601 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -1194,6 +1194,15 @@ static int cpuset_can_attach(struct cgroup_subsys *ss,
 
 	if (cpus_empty(cs->cpus_allowed) || nodes_empty(cs->mems_allowed))
 		return -ENOSPC;
+	if (tsk->flags & PF_THREAD_BOUND) {
+		cpumask_t mask;
+
+		mutex_lock(&callback_mutex);
+		mask = cs->cpus_allowed;
+		mutex_unlock(&callback_mutex);
+		if (!cpus_equal(tsk->cpus_allowed, mask))
+			return -EINVAL;
+	}
 
 	return security_task_setscheduler(tsk, 0, NULL);
 }
@@ -1207,11 +1216,14 @@ static void cpuset_attach(struct cgroup_subsys *ss,
 	struct mm_struct *mm;
 	struct cpuset *cs = cgroup_cs(cont);
 	struct cpuset *oldcs = cgroup_cs(oldcont);
+	int err;
 
 	mutex_lock(&callback_mutex);
 	guarantee_online_cpus(cs, &cpus);
-	set_cpus_allowed_ptr(tsk, &cpus);
+	err = set_cpus_allowed_ptr(tsk, &cpus);
 	mutex_unlock(&callback_mutex);
+	if (err)
+		return;
 
 	from = oldcs->mems_allowed;
 	to = cs->mems_allowed;
diff --git a/kernel/kthread.c b/kernel/kthread.c
index bd1b9ea..97747cd 100644
--- a/kernel/kthread.c
+++ b/kernel/kthread.c
@@ -180,6 +180,7 @@ void kthread_bind(struct task_struct *k, unsigned int cpu)
 	set_task_cpu(k, cpu);
 	k->cpus_allowed = cpumask_of_cpu(cpu);
 	k->rt.nr_cpus_allowed = 1;
+	k->flags |= PF_THREAD_BOUND;
 }
 EXPORT_SYMBOL(kthread_bind);
 
diff --git a/kernel/sched.c b/kernel/sched.c
index 4e2f603..d16c8d9 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -74,6 +74,8 @@
 #include <asm/tlb.h>
 #include <asm/irq_regs.h>
 
+#include "sched_cpupri.h"
+
 /*
  * Convert user-nice values [ -20 ... 0 ... 19 ]
  * to static priority [ MAX_RT_PRIO..MAX_PRIO-1 ],
@@ -289,15 +291,15 @@ struct task_group root_task_group;
 static DEFINE_PER_CPU(struct sched_entity, init_sched_entity);
 /* Default task group's cfs_rq on each cpu */
 static DEFINE_PER_CPU(struct cfs_rq, init_cfs_rq) ____cacheline_aligned_in_smp;
-#endif
+#endif /* CONFIG_FAIR_GROUP_SCHED */
 
 #ifdef CONFIG_RT_GROUP_SCHED
 static DEFINE_PER_CPU(struct sched_rt_entity, init_sched_rt_entity);
 static DEFINE_PER_CPU(struct rt_rq, init_rt_rq) ____cacheline_aligned_in_smp;
-#endif
-#else
+#endif /* CONFIG_RT_GROUP_SCHED */
+#else /* !CONFIG_FAIR_GROUP_SCHED */
 #define root_task_group init_task_group
-#endif
+#endif /* CONFIG_FAIR_GROUP_SCHED */
 
 /* task_group_lock serializes add/remove of task groups and also changes to
  * a task group's cpu shares.
@@ -307,9 +309,9 @@ static DEFINE_SPINLOCK(task_group_lock);
 #ifdef CONFIG_FAIR_GROUP_SCHED
 #ifdef CONFIG_USER_SCHED
 # define INIT_TASK_GROUP_LOAD	(2*NICE_0_LOAD)
-#else
+#else /* !CONFIG_USER_SCHED */
 # define INIT_TASK_GROUP_LOAD	NICE_0_LOAD
-#endif
+#endif /* CONFIG_USER_SCHED */
 
 /*
  * A weight of 0 or 1 can cause arithmetics problems.
@@ -363,6 +365,10 @@ static inline void set_task_rq(struct task_struct *p, unsigned int cpu)
 #else
 
 static inline void set_task_rq(struct task_struct *p, unsigned int cpu) { }
+static inline struct task_group *task_group(struct task_struct *p)
+{
+	return NULL;
+}
 
 #endif	/* CONFIG_GROUP_SCHED */
 
@@ -373,6 +379,7 @@ struct cfs_rq {
 
 	u64 exec_clock;
 	u64 min_vruntime;
+	u64 pair_start;
 
 	struct rb_root tasks_timeline;
 	struct rb_node *rb_leftmost;
@@ -401,6 +408,31 @@ struct cfs_rq {
 	 */
 	struct list_head leaf_cfs_rq_list;
 	struct task_group *tg;	/* group that "owns" this runqueue */
+
+#ifdef CONFIG_SMP
+	/*
+	 * the part of load.weight contributed by tasks
+	 */
+	unsigned long task_weight;
+
+	/*
+	 *   h_load = weight * f(tg)
+	 *
+	 * Where f(tg) is the recursive weight fraction assigned to
+	 * this group.
+	 */
+	unsigned long h_load;
+
+	/*
+	 * this cpu's part of tg->shares
+	 */
+	unsigned long shares;
+
+	/*
+	 * load.weight at the time we set shares
+	 */
+	unsigned long rq_weight;
+#endif
 #endif
 };
 
@@ -452,6 +484,9 @@ struct root_domain {
 	 */
 	cpumask_t rto_mask;
 	atomic_t rto_count;
+#ifdef CONFIG_SMP
+	struct cpupri cpupri;
+#endif
 };
 
 /*
@@ -526,6 +561,9 @@ struct rq {
 	int push_cpu;
 	/* cpu of this runqueue: */
 	int cpu;
+	int online;
+
+	unsigned long avg_load_per_task;
 
 	struct task_struct *migration_thread;
 	struct list_head migration_queue;
@@ -749,6 +787,12 @@ late_initcall(sched_init_debug);
 const_debug unsigned int sysctl_sched_nr_migrate = 32;
 
 /*
+ * ratelimit for updating the group shares.
+ * default: 0.5ms
+ */
+const_debug unsigned int sysctl_sched_shares_ratelimit = 500000;
+
+/*
  * period over which we measure -rt task cpu usage in us.
  * default: 1s
  */
@@ -775,82 +819,6 @@ static inline u64 global_rt_runtime(void)
 	return (u64)sysctl_sched_rt_runtime * NSEC_PER_USEC;
 }
 
-unsigned long long time_sync_thresh = 100000;
-
-static DEFINE_PER_CPU(unsigned long long, time_offset);
-static DEFINE_PER_CPU(unsigned long long, prev_cpu_time);
-
-/*
- * Global lock which we take every now and then to synchronize
- * the CPUs time. This method is not warp-safe, but it's good
- * enough to synchronize slowly diverging time sources and thus
- * it's good enough for tracing:
- */
-static DEFINE_SPINLOCK(time_sync_lock);
-static unsigned long long prev_global_time;
-
-static unsigned long long __sync_cpu_clock(unsigned long long time, int cpu)
-{
-	/*
-	 * We want this inlined, to not get tracer function calls
-	 * in this critical section:
-	 */
-	spin_acquire(&time_sync_lock.dep_map, 0, 0, _THIS_IP_);
-	__raw_spin_lock(&time_sync_lock.raw_lock);
-
-	if (time < prev_global_time) {
-		per_cpu(time_offset, cpu) += prev_global_time - time;
-		time = prev_global_time;
-	} else {
-		prev_global_time = time;
-	}
-
-	__raw_spin_unlock(&time_sync_lock.raw_lock);
-	spin_release(&time_sync_lock.dep_map, 1, _THIS_IP_);
-
-	return time;
-}
-
-static unsigned long long __cpu_clock(int cpu)
-{
-	unsigned long long now;
-
-	/*
-	 * Only call sched_clock() if the scheduler has already been
-	 * initialized (some code might call cpu_clock() very early):
-	 */
-	if (unlikely(!scheduler_running))
-		return 0;
-
-	now = sched_clock_cpu(cpu);
-
-	return now;
-}
-
-/*
- * For kernel-internal use: high-speed (but slightly incorrect) per-cpu
- * clock constructed from sched_clock():
- */
-unsigned long long cpu_clock(int cpu)
-{
-	unsigned long long prev_cpu_time, time, delta_time;
-	unsigned long flags;
-
-	local_irq_save(flags);
-	prev_cpu_time = per_cpu(prev_cpu_time, cpu);
-	time = __cpu_clock(cpu) + per_cpu(time_offset, cpu);
-	delta_time = time-prev_cpu_time;
-
-	if (unlikely(delta_time > time_sync_thresh)) {
-		time = __sync_cpu_clock(time, cpu);
-		per_cpu(prev_cpu_time, cpu) = time;
-	}
-	local_irq_restore(flags);
-
-	return time;
-}
-EXPORT_SYMBOL_GPL(cpu_clock);
-
 #ifndef prepare_arch_switch
 # define prepare_arch_switch(next)	do { } while (0)
 #endif
@@ -1313,15 +1281,15 @@ void wake_up_idle_cpu(int cpu)
 	if (!tsk_is_polling(rq->idle))
 		smp_send_reschedule(cpu);
 }
-#endif
+#endif /* CONFIG_NO_HZ */
 
-#else
+#else /* !CONFIG_SMP */
 static void __resched_task(struct task_struct *p, int tif_bit)
 {
 	assert_spin_locked(&task_rq(p)->lock);
 	set_tsk_thread_flag(p, tif_bit);
 }
-#endif
+#endif /* CONFIG_SMP */
 
 #if BITS_PER_LONG == 32
 # define WMULT_CONST	(~0UL)
@@ -1336,6 +1304,9 @@ static void __resched_task(struct task_struct *p, int tif_bit)
  */
 #define SRR(x, y) (((x) + (1UL << ((y) - 1))) >> (y))
 
+/*
+ * delta *= weight / lw
+ */
 static unsigned long
 calc_delta_mine(unsigned long delta_exec, unsigned long weight,
 		struct load_weight *lw)
@@ -1363,12 +1334,6 @@ calc_delta_mine(unsigned long delta_exec, unsigned long weight,
 	return (unsigned long)min(tmp, (u64)(unsigned long)LONG_MAX);
 }
 
-static inline unsigned long
-calc_delta_fair(unsigned long delta_exec, struct load_weight *lw)
-{
-	return calc_delta_mine(delta_exec, NICE_0_LOAD, lw);
-}
-
 static inline void update_load_add(struct load_weight *lw, unsigned long inc)
 {
 	lw->weight += inc;
@@ -1479,17 +1444,211 @@ static inline void dec_cpu_load(struct rq *rq, unsigned long load)
 #ifdef CONFIG_SMP
 static unsigned long source_load(int cpu, int type);
 static unsigned long target_load(int cpu, int type);
-static unsigned long cpu_avg_load_per_task(int cpu);
 static int task_hot(struct task_struct *p, u64 now, struct sched_domain *sd);
-#else /* CONFIG_SMP */
+
+static unsigned long cpu_avg_load_per_task(int cpu)
+{
+	struct rq *rq = cpu_rq(cpu);
+
+	if (rq->nr_running)
+		rq->avg_load_per_task = rq->load.weight / rq->nr_running;
+
+	return rq->avg_load_per_task;
+}
 
 #ifdef CONFIG_FAIR_GROUP_SCHED
-static void cfs_rq_set_shares(struct cfs_rq *cfs_rq, unsigned long shares)
+
+typedef void (*tg_visitor)(struct task_group *, int, struct sched_domain *);
+
+/*
+ * Iterate the full tree, calling @down when first entering a node and @up when
+ * leaving it for the final time.
+ */
+static void
+walk_tg_tree(tg_visitor down, tg_visitor up, int cpu, struct sched_domain *sd)
+{
+	struct task_group *parent, *child;
+
+	rcu_read_lock();
+	parent = &root_task_group;
+down:
+	(*down)(parent, cpu, sd);
+	list_for_each_entry_rcu(child, &parent->children, siblings) {
+		parent = child;
+		goto down;
+
+up:
+		continue;
+	}
+	(*up)(parent, cpu, sd);
+
+	child = parent;
+	parent = parent->parent;
+	if (parent)
+		goto up;
+	rcu_read_unlock();
+}
+
+static void __set_se_shares(struct sched_entity *se, unsigned long shares);
+
+/*
+ * Calculate and set the cpu's group shares.
+ */
+static void
+__update_group_shares_cpu(struct task_group *tg, int cpu,
+			  unsigned long sd_shares, unsigned long sd_rq_weight)
 {
+	int boost = 0;
+	unsigned long shares;
+	unsigned long rq_weight;
+
+	if (!tg->se[cpu])
+		return;
+
+	rq_weight = tg->cfs_rq[cpu]->load.weight;
+
+	/*
+	 * If there are currently no tasks on the cpu pretend there is one of
+	 * average load so that when a new task gets to run here it will not
+	 * get delayed by group starvation.
+	 */
+	if (!rq_weight) {
+		boost = 1;
+		rq_weight = NICE_0_LOAD;
+	}
+
+	if (unlikely(rq_weight > sd_rq_weight))
+		rq_weight = sd_rq_weight;
+
+	/*
+	 *           \Sum shares * rq_weight
+	 * shares =  -----------------------
+	 *               \Sum rq_weight
+	 *
+	 */
+	shares = (sd_shares * rq_weight) / (sd_rq_weight + 1);
+
+	/*
+	 * record the actual number of shares, not the boosted amount.
+	 */
+	tg->cfs_rq[cpu]->shares = boost ? 0 : shares;
+	tg->cfs_rq[cpu]->rq_weight = rq_weight;
+
+	if (shares < MIN_SHARES)
+		shares = MIN_SHARES;
+	else if (shares > MAX_SHARES)
+		shares = MAX_SHARES;
+
+	__set_se_shares(tg->se[cpu], shares);
 }
+
+/*
+ * Re-compute the task group their per cpu shares over the given domain.
+ * This needs to be done in a bottom-up fashion because the rq weight of a
+ * parent group depends on the shares of its child groups.
+ */
+static void
+tg_shares_up(struct task_group *tg, int cpu, struct sched_domain *sd)
+{
+	unsigned long rq_weight = 0;
+	unsigned long shares = 0;
+	int i;
+
+	for_each_cpu_mask(i, sd->span) {
+		rq_weight += tg->cfs_rq[i]->load.weight;
+		shares += tg->cfs_rq[i]->shares;
+	}
+
+	if ((!shares && rq_weight) || shares > tg->shares)
+		shares = tg->shares;
+
+	if (!sd->parent || !(sd->parent->flags & SD_LOAD_BALANCE))
+		shares = tg->shares;
+
+	if (!rq_weight)
+		rq_weight = cpus_weight(sd->span) * NICE_0_LOAD;
+
+	for_each_cpu_mask(i, sd->span) {
+		struct rq *rq = cpu_rq(i);
+		unsigned long flags;
+
+		spin_lock_irqsave(&rq->lock, flags);
+		__update_group_shares_cpu(tg, i, shares, rq_weight);
+		spin_unlock_irqrestore(&rq->lock, flags);
+	}
+}
+
+/*
+ * Compute the cpu's hierarchical load factor for each task group.
+ * This needs to be done in a top-down fashion because the load of a child
+ * group is a fraction of its parents load.
+ */
+static void
+tg_load_down(struct task_group *tg, int cpu, struct sched_domain *sd)
+{
+	unsigned long load;
+
+	if (!tg->parent) {
+		load = cpu_rq(cpu)->load.weight;
+	} else {
+		load = tg->parent->cfs_rq[cpu]->h_load;
+		load *= tg->cfs_rq[cpu]->shares;
+		load /= tg->parent->cfs_rq[cpu]->load.weight + 1;
+	}
+
+	tg->cfs_rq[cpu]->h_load = load;
+}
+
+static void
+tg_nop(struct task_group *tg, int cpu, struct sched_domain *sd)
+{
+}
+
+static void update_shares(struct sched_domain *sd)
+{
+	u64 now = cpu_clock(raw_smp_processor_id());
+	s64 elapsed = now - sd->last_update;
+
+	if (elapsed >= (s64)(u64)sysctl_sched_shares_ratelimit) {
+		sd->last_update = now;
+		walk_tg_tree(tg_nop, tg_shares_up, 0, sd);
+	}
+}
+
+static void update_shares_locked(struct rq *rq, struct sched_domain *sd)
+{
+	spin_unlock(&rq->lock);
+	update_shares(sd);
+	spin_lock(&rq->lock);
+}
+
+static void update_h_load(int cpu)
+{
+	walk_tg_tree(tg_load_down, tg_nop, cpu, NULL);
+}
+
+#else
+
+static inline void update_shares(struct sched_domain *sd)
+{
+}
+
+static inline void update_shares_locked(struct rq *rq, struct sched_domain *sd)
+{
+}
+
 #endif
 
-#endif /* CONFIG_SMP */
+#endif
+
+#ifdef CONFIG_FAIR_GROUP_SCHED
+static void cfs_rq_set_shares(struct cfs_rq *cfs_rq, unsigned long shares)
+{
+#ifdef CONFIG_SMP
+	cfs_rq->shares = shares;
+#endif
+}
+#endif
 
 #include "sched_stats.h"
 #include "sched_idletask.c"
@@ -1500,27 +1659,17 @@ static void cfs_rq_set_shares(struct cfs_rq *cfs_rq, unsigned long shares)
 #endif
 
 #define sched_class_highest (&rt_sched_class)
+#define for_each_class(class) \
+   for (class = sched_class_highest; class; class = class->next)
 
-static inline void inc_load(struct rq *rq, const struct task_struct *p)
-{
-	update_load_add(&rq->load, p->se.load.weight);
-}
-
-static inline void dec_load(struct rq *rq, const struct task_struct *p)
-{
-	update_load_sub(&rq->load, p->se.load.weight);
-}
-
-static void inc_nr_running(struct task_struct *p, struct rq *rq)
+static void inc_nr_running(struct rq *rq)
 {
 	rq->nr_running++;
-	inc_load(rq, p);
 }
 
-static void dec_nr_running(struct task_struct *p, struct rq *rq)
+static void dec_nr_running(struct rq *rq)
 {
 	rq->nr_running--;
-	dec_load(rq, p);
 }
 
 static void set_load_weight(struct task_struct *p)
@@ -1544,6 +1693,12 @@ static void set_load_weight(struct task_struct *p)
 	p->se.load.inv_weight = prio_to_wmult[p->static_prio - MAX_RT_PRIO];
 }
 
+static void update_avg(u64 *avg, u64 sample)
+{
+	s64 diff = sample - *avg;
+	*avg += diff >> 3;
+}
+
 static void enqueue_task(struct rq *rq, struct task_struct *p, int wakeup)
 {
 	sched_info_queued(p);
@@ -1553,6 +1708,13 @@ static void enqueue_task(struct rq *rq, struct task_struct *p, int wakeup)
 
 static void dequeue_task(struct rq *rq, struct task_struct *p, int sleep)
 {
+	if (sleep && p->se.last_wakeup) {
+		update_avg(&p->se.avg_overlap,
+			   p->se.sum_exec_runtime - p->se.last_wakeup);
+		p->se.last_wakeup = 0;
+	}
+
+	sched_info_dequeued(p);
 	p->sched_class->dequeue_task(rq, p, sleep);
 	p->se.on_rq = 0;
 }
@@ -1612,7 +1774,7 @@ static void activate_task(struct rq *rq, struct task_struct *p, int wakeup)
 		rq->nr_uninterruptible--;
 
 	enqueue_task(rq, p, wakeup);
-	inc_nr_running(p, rq);
+	inc_nr_running(rq);
 }
 
 /*
@@ -1624,7 +1786,7 @@ static void deactivate_task(struct rq *rq, struct task_struct *p, int sleep)
 		rq->nr_uninterruptible++;
 
 	dequeue_task(rq, p, sleep);
-	dec_nr_running(p, rq);
+	dec_nr_running(rq);
 }
 
 /**
@@ -1636,12 +1798,6 @@ inline int task_curr(const struct task_struct *p)
 	return cpu_curr(task_cpu(p)) == p;
 }
 
-/* Used instead of source_load when we know the type == 0 */
-unsigned long weighted_cpuload(const int cpu)
-{
-	return cpu_rq(cpu)->load.weight;
-}
-
 static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu)
 {
 	set_task_rq(p, cpu);
@@ -1670,6 +1826,12 @@ static inline void check_class_changed(struct rq *rq, struct task_struct *p,
 
 #ifdef CONFIG_SMP
 
+/* Used instead of source_load when we know the type == 0 */
+static unsigned long weighted_cpuload(const int cpu)
+{
+	return cpu_rq(cpu)->load.weight;
+}
+
 /*
  * Is this task likely cache-hot:
  */
@@ -1880,7 +2042,7 @@ static unsigned long source_load(int cpu, int type)
 	struct rq *rq = cpu_rq(cpu);
 	unsigned long total = weighted_cpuload(cpu);
 
-	if (type == 0)
+	if (type == 0 || !sched_feat(LB_BIAS))
 		return total;
 
 	return min(rq->cpu_load[type-1], total);
@@ -1895,25 +2057,13 @@ static unsigned long target_load(int cpu, int type)
 	struct rq *rq = cpu_rq(cpu);
 	unsigned long total = weighted_cpuload(cpu);
 
-	if (type == 0)
+	if (type == 0 || !sched_feat(LB_BIAS))
 		return total;
 
 	return max(rq->cpu_load[type-1], total);
 }
 
 /*
- * Return the average load per task on the cpu's run queue
- */
-static unsigned long cpu_avg_load_per_task(int cpu)
-{
-	struct rq *rq = cpu_rq(cpu);
-	unsigned long total = weighted_cpuload(cpu);
-	unsigned long n = rq->nr_running;
-
-	return n ? total / n : SCHED_LOAD_SCALE;
-}
-
-/*
  * find_idlest_group finds and returns the least busy CPU group within the
  * domain.
  */
@@ -2019,6 +2169,9 @@ static int sched_balance_self(int cpu, int flag)
 			sd = tmp;
 	}
 
+	if (sd)
+		update_shares(sd);
+
 	while (sd) {
 		cpumask_t span, tmpmask;
 		struct sched_group *group;
@@ -2085,6 +2238,22 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync)
 	if (!sched_feat(SYNC_WAKEUPS))
 		sync = 0;
 
+#ifdef CONFIG_SMP
+	if (sched_feat(LB_WAKEUP_UPDATE)) {
+		struct sched_domain *sd;
+
+		this_cpu = raw_smp_processor_id();
+		cpu = task_cpu(p);
+
+		for_each_domain(this_cpu, sd) {
+			if (cpu_isset(cpu, sd->span)) {
+				update_shares(sd);
+				break;
+			}
+		}
+	}
+#endif
+
 	smp_wmb();
 	rq = task_rq_lock(p, &flags);
 	old_state = p->state;
@@ -2131,7 +2300,7 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync)
 			}
 		}
 	}
-#endif
+#endif /* CONFIG_SCHEDSTATS */
 
 out_activate:
 #endif /* CONFIG_SMP */
@@ -2157,6 +2326,8 @@ out_running:
 		p->sched_class->task_wake_up(rq, p);
 #endif
 out:
+	current->se.last_wakeup = current->se.sum_exec_runtime;
+
 	task_rq_unlock(rq, &flags);
 
 	return success;
@@ -2277,7 +2448,7 @@ void wake_up_new_task(struct task_struct *p, unsigned long clone_flags)
 		 * management (if any):
 		 */
 		p->sched_class->task_new(rq, p);
-		inc_nr_running(p, rq);
+		inc_nr_running(rq);
 	}
 	check_preempt_curr(rq, p);
 #ifdef CONFIG_SMP
@@ -2331,7 +2502,7 @@ fire_sched_out_preempt_notifiers(struct task_struct *curr,
 		notifier->ops->sched_out(notifier, next);
 }
 
-#else
+#else /* !CONFIG_PREEMPT_NOTIFIERS */
 
 static void fire_sched_in_preempt_notifiers(struct task_struct *curr)
 {
@@ -2343,7 +2514,7 @@ fire_sched_out_preempt_notifiers(struct task_struct *curr,
 {
 }
 
-#endif
+#endif /* CONFIG_PREEMPT_NOTIFIERS */
 
 /**
  * prepare_task_switch - prepare to switch tasks
@@ -2785,7 +2956,7 @@ balance_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest,
 	      enum cpu_idle_type idle, int *all_pinned,
 	      int *this_best_prio, struct rq_iterator *iterator)
 {
-	int loops = 0, pulled = 0, pinned = 0, skip_for_load;
+	int loops = 0, pulled = 0, pinned = 0;
 	struct task_struct *p;
 	long rem_load_move = max_load_move;
 
@@ -2801,14 +2972,8 @@ balance_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest,
 next:
 	if (!p || loops++ > sysctl_sched_nr_migrate)
 		goto out;
-	/*
-	 * To help distribute high priority tasks across CPUs we don't
-	 * skip a task if it will be the highest priority task (i.e. smallest
-	 * prio value) on its new queue regardless of its load weight
-	 */
-	skip_for_load = (p->se.load.weight >> 1) > rem_load_move +
-							 SCHED_LOAD_SCALE_FUZZ;
-	if ((skip_for_load && p->prio >= *this_best_prio) ||
+
+	if ((p->se.load.weight >> 1) > rem_load_move ||
 	    !can_migrate_task(p, busiest, this_cpu, sd, idle, &pinned)) {
 		p = iterator->next(iterator->arg);
 		goto next;
@@ -2863,6 +3028,10 @@ static int move_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest,
 				max_load_move - total_load_moved,
 				sd, idle, all_pinned, &this_best_prio);
 		class = class->next;
+
+		if (idle == CPU_NEWLY_IDLE && this_rq->nr_running)
+			break;
+
 	} while (class && max_load_move > total_load_moved);
 
 	return total_load_moved > 0;
@@ -2939,6 +3108,7 @@ find_busiest_group(struct sched_domain *sd, int this_cpu,
 	max_load = this_load = total_load = total_pwr = 0;
 	busiest_load_per_task = busiest_nr_running = 0;
 	this_load_per_task = this_nr_running = 0;
+
 	if (idle == CPU_NOT_IDLE)
 		load_idx = sd->busy_idx;
 	else if (idle == CPU_NEWLY_IDLE)
@@ -2953,6 +3123,8 @@ find_busiest_group(struct sched_domain *sd, int this_cpu,
 		int __group_imb = 0;
 		unsigned int balance_cpu = -1, first_idle_cpu = 0;
 		unsigned long sum_nr_running, sum_weighted_load;
+		unsigned long sum_avg_load_per_task;
+		unsigned long avg_load_per_task;
 
 		local_group = cpu_isset(this_cpu, group->cpumask);
 
@@ -2961,6 +3133,8 @@ find_busiest_group(struct sched_domain *sd, int this_cpu,
 
 		/* Tally up the load of all CPUs in the group */
 		sum_weighted_load = sum_nr_running = avg_load = 0;
+		sum_avg_load_per_task = avg_load_per_task = 0;
+
 		max_cpu_load = 0;
 		min_cpu_load = ~0UL;
 
@@ -2994,6 +3168,8 @@ find_busiest_group(struct sched_domain *sd, int this_cpu,
 			avg_load += load;
 			sum_nr_running += rq->nr_running;
 			sum_weighted_load += weighted_cpuload(i);
+
+			sum_avg_load_per_task += cpu_avg_load_per_task(i);
 		}
 
 		/*
@@ -3015,7 +3191,20 @@ find_busiest_group(struct sched_domain *sd, int this_cpu,
 		avg_load = sg_div_cpu_power(group,
 				avg_load * SCHED_LOAD_SCALE);
 
-		if ((max_cpu_load - min_cpu_load) > SCHED_LOAD_SCALE)
+
+		/*
+		 * Consider the group unbalanced when the imbalance is larger
+		 * than the average weight of two tasks.
+		 *
+		 * APZ: with cgroup the avg task weight can vary wildly and
+		 *      might not be a suitable number - should we keep a
+		 *      normalized nr_running number somewhere that negates
+		 *      the hierarchy?
+		 */
+		avg_load_per_task = sg_div_cpu_power(group,
+				sum_avg_load_per_task * SCHED_LOAD_SCALE);
+
+		if ((max_cpu_load - min_cpu_load) > 2*avg_load_per_task)
 			__group_imb = 1;
 
 		group_capacity = group->__cpu_power / SCHED_LOAD_SCALE;
@@ -3156,9 +3345,9 @@ small_imbalance:
 			if (busiest_load_per_task > this_load_per_task)
 				imbn = 1;
 		} else
-			this_load_per_task = SCHED_LOAD_SCALE;
+			this_load_per_task = cpu_avg_load_per_task(this_cpu);
 
-		if (max_load - this_load + SCHED_LOAD_SCALE_FUZZ >=
+		if (max_load - this_load + 2*busiest_load_per_task >=
 					busiest_load_per_task * imbn) {
 			*imbalance = busiest_load_per_task;
 			return busiest;
@@ -3284,6 +3473,7 @@ static int load_balance(int this_cpu, struct rq *this_rq,
 	schedstat_inc(sd, lb_count[idle]);
 
 redo:
+	update_shares(sd);
 	group = find_busiest_group(sd, this_cpu, &imbalance, idle, &sd_idle,
 				   cpus, balance);
 
@@ -3386,8 +3576,9 @@ redo:
 
 	if (!ld_moved && !sd_idle && sd->flags & SD_SHARE_CPUPOWER &&
 	    !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE))
-		return -1;
-	return ld_moved;
+		ld_moved = -1;
+
+	goto out;
 
 out_balanced:
 	schedstat_inc(sd, lb_balanced[idle]);
@@ -3402,8 +3593,13 @@ out_one_pinned:
 
 	if (!sd_idle && sd->flags & SD_SHARE_CPUPOWER &&
 	    !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE))
-		return -1;
-	return 0;
+		ld_moved = -1;
+	else
+		ld_moved = 0;
+out:
+	if (ld_moved)
+		update_shares(sd);
+	return ld_moved;
 }
 
 /*
@@ -3438,6 +3634,7 @@ load_balance_newidle(int this_cpu, struct rq *this_rq, struct sched_domain *sd,
 
 	schedstat_inc(sd, lb_count[CPU_NEWLY_IDLE]);
 redo:
+	update_shares_locked(this_rq, sd);
 	group = find_busiest_group(sd, this_cpu, &imbalance, CPU_NEWLY_IDLE,
 				   &sd_idle, cpus, NULL);
 	if (!group) {
@@ -3481,6 +3678,7 @@ redo:
 	} else
 		sd->nr_balance_failed = 0;
 
+	update_shares_locked(this_rq, sd);
 	return ld_moved;
 
 out_balanced:
@@ -3672,6 +3870,7 @@ static void rebalance_domains(int cpu, enum cpu_idle_type idle)
 	/* Earliest time when we have to do rebalance again */
 	unsigned long next_balance = jiffies + 60*HZ;
 	int update_next_balance = 0;
+	int need_serialize;
 	cpumask_t tmp;
 
 	for_each_domain(cpu, sd) {
@@ -3689,8 +3888,9 @@ static void rebalance_domains(int cpu, enum cpu_idle_type idle)
 		if (interval > HZ*NR_CPUS/10)
 			interval = HZ*NR_CPUS/10;
 
+		need_serialize = sd->flags & SD_SERIALIZE;
 
-		if (sd->flags & SD_SERIALIZE) {
+		if (need_serialize) {
 			if (!spin_trylock(&balancing))
 				goto out;
 		}
@@ -3706,7 +3906,7 @@ static void rebalance_domains(int cpu, enum cpu_idle_type idle)
 			}
 			sd->last_balance = jiffies;
 		}
-		if (sd->flags & SD_SERIALIZE)
+		if (need_serialize)
 			spin_unlock(&balancing);
 out:
 		if (time_after(next_balance, sd->last_balance + interval)) {
@@ -4070,6 +4270,7 @@ static noinline void __schedule_bug(struct task_struct *prev)
 		prev->comm, prev->pid, preempt_count());
 
 	debug_show_held_locks(prev);
+	print_modules();
 	if (irqs_disabled())
 		print_irqtrace_events(prev);
 
@@ -4143,7 +4344,7 @@ asmlinkage void __sched schedule(void)
 	struct task_struct *prev, *next;
 	unsigned long *switch_count;
 	struct rq *rq;
-	int cpu;
+	int cpu, hrtick = sched_feat(HRTICK);
 
 need_resched:
 	preempt_disable();
@@ -4158,7 +4359,8 @@ need_resched_nonpreemptible:
 
 	schedule_debug(prev);
 
-	hrtick_clear(rq);
+	if (hrtick)
+		hrtick_clear(rq);
 
 	/*
 	 * Do the rq-clock update outside the rq lock:
@@ -4204,7 +4406,8 @@ need_resched_nonpreemptible:
 	} else
 		spin_unlock_irq(&rq->lock);
 
-	hrtick_set(rq);
+	if (hrtick)
+		hrtick_set(rq);
 
 	if (unlikely(reacquire_kernel_lock(current) < 0))
 		goto need_resched_nonpreemptible;
@@ -4586,10 +4789,8 @@ void set_user_nice(struct task_struct *p, long nice)
 		goto out_unlock;
 	}
 	on_rq = p->se.on_rq;
-	if (on_rq) {
+	if (on_rq)
 		dequeue_task(rq, p, 0);
-		dec_load(rq, p);
-	}
 
 	p->static_prio = NICE_TO_PRIO(nice);
 	set_load_weight(p);
@@ -4599,7 +4800,6 @@ void set_user_nice(struct task_struct *p, long nice)
 
 	if (on_rq) {
 		enqueue_task(rq, p, 0);
-		inc_load(rq, p);
 		/*
 		 * If the task increased its priority or is running and
 		 * lowered its priority, then reschedule its CPU:
@@ -5070,24 +5270,6 @@ asmlinkage long sys_sched_setaffinity(pid_t pid, unsigned int len,
 	return sched_setaffinity(pid, &new_mask);
 }
 
-/*
- * Represents all cpu's present in the system
- * In systems capable of hotplug, this map could dynamically grow
- * as new cpu's are detected in the system via any platform specific
- * method, such as ACPI for e.g.
- */
-
-cpumask_t cpu_present_map __read_mostly;
-EXPORT_SYMBOL(cpu_present_map);
-
-#ifndef CONFIG_SMP
-cpumask_t cpu_online_map __read_mostly = CPU_MASK_ALL;
-EXPORT_SYMBOL(cpu_online_map);
-
-cpumask_t cpu_possible_map __read_mostly = CPU_MASK_ALL;
-EXPORT_SYMBOL(cpu_possible_map);
-#endif
-
 long sched_getaffinity(pid_t pid, cpumask_t *mask)
 {
 	struct task_struct *p;
@@ -5571,6 +5753,12 @@ int set_cpus_allowed_ptr(struct task_struct *p, const cpumask_t *new_mask)
 		goto out;
 	}
 
+	if (unlikely((p->flags & PF_THREAD_BOUND) && p != current &&
+		     !cpus_equal(p->cpus_allowed, *new_mask))) {
+		ret = -EINVAL;
+		goto out;
+	}
+
 	if (p->sched_class->set_cpus_allowed)
 		p->sched_class->set_cpus_allowed(p, new_mask);
 	else {
@@ -6060,6 +6248,36 @@ static void unregister_sched_domain_sysctl(void)
 }
 #endif
 
+static void set_rq_online(struct rq *rq)
+{
+	if (!rq->online) {
+		const struct sched_class *class;
+
+		cpu_set(rq->cpu, rq->rd->online);
+		rq->online = 1;
+
+		for_each_class(class) {
+			if (class->rq_online)
+				class->rq_online(rq);
+		}
+	}
+}
+
+static void set_rq_offline(struct rq *rq)
+{
+	if (rq->online) {
+		const struct sched_class *class;
+
+		for_each_class(class) {
+			if (class->rq_offline)
+				class->rq_offline(rq);
+		}
+
+		cpu_clear(rq->cpu, rq->rd->online);
+		rq->online = 0;
+	}
+}
+
 /*
  * migration_call - callback that gets triggered when a CPU is added.
  * Here we can start up the necessary migration thread for the new CPU.
@@ -6097,7 +6315,8 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
 		spin_lock_irqsave(&rq->lock, flags);
 		if (rq->rd) {
 			BUG_ON(!cpu_isset(cpu, rq->rd->span));
-			cpu_set(cpu, rq->rd->online);
+
+			set_rq_online(rq);
 		}
 		spin_unlock_irqrestore(&rq->lock, flags);
 		break;
@@ -6158,7 +6377,7 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
 		spin_lock_irqsave(&rq->lock, flags);
 		if (rq->rd) {
 			BUG_ON(!cpu_isset(cpu, rq->rd->span));
-			cpu_clear(cpu, rq->rd->online);
+			set_rq_offline(rq);
 		}
 		spin_unlock_irqrestore(&rq->lock, flags);
 		break;
@@ -6192,6 +6411,28 @@ void __init migration_init(void)
 
 #ifdef CONFIG_SCHED_DEBUG
 
+static inline const char *sd_level_to_string(enum sched_domain_level lvl)
+{
+	switch (lvl) {
+	case SD_LV_NONE:
+			return "NONE";
+	case SD_LV_SIBLING:
+			return "SIBLING";
+	case SD_LV_MC:
+			return "MC";
+	case SD_LV_CPU:
+			return "CPU";
+	case SD_LV_NODE:
+			return "NODE";
+	case SD_LV_ALLNODES:
+			return "ALLNODES";
+	case SD_LV_MAX:
+			return "MAX";
+
+	}
+	return "MAX";
+}
+
 static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level,
 				  cpumask_t *groupmask)
 {
@@ -6211,7 +6452,8 @@ static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level,
 		return -1;
 	}
 
-	printk(KERN_CONT "span %s\n", str);
+	printk(KERN_CONT "span %s level %s\n",
+		str, sd_level_to_string(sd->level));
 
 	if (!cpu_isset(cpu, sd->span)) {
 		printk(KERN_ERR "ERROR: domain->span does not contain "
@@ -6295,9 +6537,9 @@ static void sched_domain_debug(struct sched_domain *sd, int cpu)
 	}
 	kfree(groupmask);
 }
-#else
+#else /* !CONFIG_SCHED_DEBUG */
 # define sched_domain_debug(sd, cpu) do { } while (0)
-#endif
+#endif /* CONFIG_SCHED_DEBUG */
 
 static int sd_degenerate(struct sched_domain *sd)
 {
@@ -6357,20 +6599,16 @@ sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent)
 static void rq_attach_root(struct rq *rq, struct root_domain *rd)
 {
 	unsigned long flags;
-	const struct sched_class *class;
 
 	spin_lock_irqsave(&rq->lock, flags);
 
 	if (rq->rd) {
 		struct root_domain *old_rd = rq->rd;
 
-		for (class = sched_class_highest; class; class = class->next) {
-			if (class->leave_domain)
-				class->leave_domain(rq);
-		}
+		if (cpu_isset(rq->cpu, old_rd->online))
+			set_rq_offline(rq);
 
 		cpu_clear(rq->cpu, old_rd->span);
-		cpu_clear(rq->cpu, old_rd->online);
 
 		if (atomic_dec_and_test(&old_rd->refcount))
 			kfree(old_rd);
@@ -6381,12 +6619,7 @@ static void rq_attach_root(struct rq *rq, struct root_domain *rd)
 
 	cpu_set(rq->cpu, rd->span);
 	if (cpu_isset(rq->cpu, cpu_online_map))
-		cpu_set(rq->cpu, rd->online);
-
-	for (class = sched_class_highest; class; class = class->next) {
-		if (class->join_domain)
-			class->join_domain(rq);
-	}
+		set_rq_online(rq);
 
 	spin_unlock_irqrestore(&rq->lock, flags);
 }
@@ -6397,6 +6630,8 @@ static void init_rootdomain(struct root_domain *rd)
 
 	cpus_clear(rd->span);
 	cpus_clear(rd->online);
+
+	cpupri_init(&rd->cpupri);
 }
 
 static void init_defrootdomain(void)
@@ -6591,7 +6826,7 @@ static void sched_domain_node_span(int node, cpumask_t *span)
 		cpus_or(*span, *span, *nodemask);
 	}
 }
-#endif
+#endif /* CONFIG_NUMA */
 
 int sched_smt_power_savings = 0, sched_mc_power_savings = 0;
 
@@ -6610,7 +6845,7 @@ cpu_to_cpu_group(int cpu, const cpumask_t *cpu_map, struct sched_group **sg,
 		*sg = &per_cpu(sched_group_cpus, cpu);
 	return cpu;
 }
-#endif
+#endif /* CONFIG_SCHED_SMT */
 
 /*
  * multi-core sched-domains:
@@ -6618,7 +6853,7 @@ cpu_to_cpu_group(int cpu, const cpumask_t *cpu_map, struct sched_group **sg,
 #ifdef CONFIG_SCHED_MC
 static DEFINE_PER_CPU(struct sched_domain, core_domains);
 static DEFINE_PER_CPU(struct sched_group, sched_group_core);
-#endif
+#endif /* CONFIG_SCHED_MC */
 
 #if defined(CONFIG_SCHED_MC) && defined(CONFIG_SCHED_SMT)
 static int
@@ -6720,7 +6955,7 @@ static void init_numa_sched_groups_power(struct sched_group *group_head)
 		sg = sg->next;
 	} while (sg != group_head);
 }
-#endif
+#endif /* CONFIG_NUMA */
 
 #ifdef CONFIG_NUMA
 /* Free memory allocated for various sched_group structures */
@@ -6757,11 +6992,11 @@ next_sg:
 		sched_group_nodes_bycpu[cpu] = NULL;
 	}
 }
-#else
+#else /* !CONFIG_NUMA */
 static void free_sched_groups(const cpumask_t *cpu_map, cpumask_t *nodemask)
 {
 }
-#endif
+#endif /* CONFIG_NUMA */
 
 /*
  * Initialize sched groups cpu_power.
@@ -7470,7 +7705,7 @@ int sched_create_sysfs_power_savings_entries(struct sysdev_class *cls)
 #endif
 	return err;
 }
-#endif
+#endif /* CONFIG_SCHED_MC || CONFIG_SCHED_SMT */
 
 /*
  * Force a reinitialization of the sched domains hierarchy. The domains
@@ -7481,21 +7716,28 @@ int sched_create_sysfs_power_savings_entries(struct sysdev_class *cls)
 static int update_sched_domains(struct notifier_block *nfb,
 				unsigned long action, void *hcpu)
 {
+	int cpu = (int)(long)hcpu;
+
 	switch (action) {
-	case CPU_UP_PREPARE:
-	case CPU_UP_PREPARE_FROZEN:
 	case CPU_DOWN_PREPARE:
 	case CPU_DOWN_PREPARE_FROZEN:
+		disable_runtime(cpu_rq(cpu));
+		/* fall-through */
+	case CPU_UP_PREPARE:
+	case CPU_UP_PREPARE_FROZEN:
 		detach_destroy_domains(&cpu_online_map);
 		free_sched_domains();
 		return NOTIFY_OK;
 
-	case CPU_UP_CANCELED:
-	case CPU_UP_CANCELED_FROZEN:
+
 	case CPU_DOWN_FAILED:
 	case CPU_DOWN_FAILED_FROZEN:
 	case CPU_ONLINE:
 	case CPU_ONLINE_FROZEN:
+		enable_runtime(cpu_rq(cpu));
+		/* fall-through */
+	case CPU_UP_CANCELED:
+	case CPU_UP_CANCELED_FROZEN:
 	case CPU_DEAD:
 	case CPU_DEAD_FROZEN:
 		/*
@@ -7695,8 +7937,8 @@ void __init sched_init(void)
 
 		root_task_group.cfs_rq = (struct cfs_rq **)ptr;
 		ptr += nr_cpu_ids * sizeof(void **);
-#endif
-#endif
+#endif /* CONFIG_USER_SCHED */
+#endif /* CONFIG_FAIR_GROUP_SCHED */
 #ifdef CONFIG_RT_GROUP_SCHED
 		init_task_group.rt_se = (struct sched_rt_entity **)ptr;
 		ptr += nr_cpu_ids * sizeof(void **);
@@ -7710,8 +7952,8 @@ void __init sched_init(void)
 
 		root_task_group.rt_rq = (struct rt_rq **)ptr;
 		ptr += nr_cpu_ids * sizeof(void **);
-#endif
-#endif
+#endif /* CONFIG_USER_SCHED */
+#endif /* CONFIG_RT_GROUP_SCHED */
 	}
 
 #ifdef CONFIG_SMP
@@ -7727,8 +7969,8 @@ void __init sched_init(void)
 #ifdef CONFIG_USER_SCHED
 	init_rt_bandwidth(&root_task_group.rt_bandwidth,
 			global_rt_period(), RUNTIME_INF);
-#endif
-#endif
+#endif /* CONFIG_USER_SCHED */
+#endif /* CONFIG_RT_GROUP_SCHED */
 
 #ifdef CONFIG_GROUP_SCHED
 	list_add(&init_task_group.list, &task_groups);
@@ -7738,8 +7980,8 @@ void __init sched_init(void)
 	INIT_LIST_HEAD(&root_task_group.children);
 	init_task_group.parent = &root_task_group;
 	list_add(&init_task_group.siblings, &root_task_group.children);
-#endif
-#endif
+#endif /* CONFIG_USER_SCHED */
+#endif /* CONFIG_GROUP_SCHED */
 
 	for_each_possible_cpu(i) {
 		struct rq *rq;
@@ -7819,6 +8061,7 @@ void __init sched_init(void)
 		rq->next_balance = jiffies;
 		rq->push_cpu = 0;
 		rq->cpu = i;
+		rq->online = 0;
 		rq->migration_thread = NULL;
 		INIT_LIST_HEAD(&rq->migration_queue);
 		rq_attach_root(rq, &def_root_domain);
@@ -8058,7 +8301,7 @@ static inline void unregister_fair_sched_group(struct task_group *tg, int cpu)
 {
 	list_del_rcu(&tg->cfs_rq[cpu]->leaf_cfs_rq_list);
 }
-#else
+#else /* !CONFG_FAIR_GROUP_SCHED */
 static inline void free_fair_sched_group(struct task_group *tg)
 {
 }
@@ -8076,7 +8319,7 @@ static inline void register_fair_sched_group(struct task_group *tg, int cpu)
 static inline void unregister_fair_sched_group(struct task_group *tg, int cpu)
 {
 }
-#endif
+#endif /* CONFIG_FAIR_GROUP_SCHED */
 
 #ifdef CONFIG_RT_GROUP_SCHED
 static void free_rt_sched_group(struct task_group *tg)
@@ -8147,7 +8390,7 @@ static inline void unregister_rt_sched_group(struct task_group *tg, int cpu)
 {
 	list_del_rcu(&tg->rt_rq[cpu]->leaf_rt_rq_list);
 }
-#else
+#else /* !CONFIG_RT_GROUP_SCHED */
 static inline void free_rt_sched_group(struct task_group *tg)
 {
 }
@@ -8165,7 +8408,7 @@ static inline void register_rt_sched_group(struct task_group *tg, int cpu)
 static inline void unregister_rt_sched_group(struct task_group *tg, int cpu)
 {
 }
-#endif
+#endif /* CONFIG_RT_GROUP_SCHED */
 
 #ifdef CONFIG_GROUP_SCHED
 static void free_sched_group(struct task_group *tg)
@@ -8276,17 +8519,14 @@ void sched_move_task(struct task_struct *tsk)
 
 	task_rq_unlock(rq, &flags);
 }
-#endif
+#endif /* CONFIG_GROUP_SCHED */
 
 #ifdef CONFIG_FAIR_GROUP_SCHED
-static void set_se_shares(struct sched_entity *se, unsigned long shares)
+static void __set_se_shares(struct sched_entity *se, unsigned long shares)
 {
 	struct cfs_rq *cfs_rq = se->cfs_rq;
-	struct rq *rq = cfs_rq->rq;
 	int on_rq;
 
-	spin_lock_irq(&rq->lock);
-
 	on_rq = se->on_rq;
 	if (on_rq)
 		dequeue_entity(cfs_rq, se, 0);
@@ -8296,8 +8536,17 @@ static void set_se_shares(struct sched_entity *se, unsigned long shares)
 
 	if (on_rq)
 		enqueue_entity(cfs_rq, se, 0);
+}
 
-	spin_unlock_irq(&rq->lock);
+static void set_se_shares(struct sched_entity *se, unsigned long shares)
+{
+	struct cfs_rq *cfs_rq = se->cfs_rq;
+	struct rq *rq = cfs_rq->rq;
+	unsigned long flags;
+
+	spin_lock_irqsave(&rq->lock, flags);
+	__set_se_shares(se, shares);
+	spin_unlock_irqrestore(&rq->lock, flags);
 }
 
 static DEFINE_MUTEX(shares_mutex);
@@ -8336,8 +8585,13 @@ int sched_group_set_shares(struct task_group *tg, unsigned long shares)
 	 * w/o tripping rebalance_share or load_balance_fair.
 	 */
 	tg->shares = shares;
-	for_each_possible_cpu(i)
+	for_each_possible_cpu(i) {
+		/*
+		 * force a rebalance
+		 */
+		cfs_rq_set_shares(tg->cfs_rq[i], 0);
 		set_se_shares(tg->se[i], shares);
+	}
 
 	/*
 	 * Enable load balance activity on this group, by inserting it back on
@@ -8376,7 +8630,7 @@ static unsigned long to_ratio(u64 period, u64 runtime)
 #ifdef CONFIG_CGROUP_SCHED
 static int __rt_schedulable(struct task_group *tg, u64 period, u64 runtime)
 {
-	struct task_group *tgi, *parent = tg ? tg->parent : NULL;
+	struct task_group *tgi, *parent = tg->parent;
 	unsigned long total = 0;
 
 	if (!parent) {
@@ -8400,7 +8654,7 @@ static int __rt_schedulable(struct task_group *tg, u64 period, u64 runtime)
 	}
 	rcu_read_unlock();
 
-	return total + to_ratio(period, runtime) <
+	return total + to_ratio(period, runtime) <=
 		to_ratio(ktime_to_ns(parent->rt_bandwidth.rt_period),
 				parent->rt_bandwidth.rt_runtime);
 }
@@ -8520,16 +8774,21 @@ long sched_group_rt_period(struct task_group *tg)
 
 static int sched_rt_global_constraints(void)
 {
+	struct task_group *tg = &root_task_group;
+	u64 rt_runtime, rt_period;
 	int ret = 0;
 
+	rt_period = ktime_to_ns(tg->rt_bandwidth.rt_period);
+	rt_runtime = tg->rt_bandwidth.rt_runtime;
+
 	mutex_lock(&rt_constraints_mutex);
-	if (!__rt_schedulable(NULL, 1, 0))
+	if (!__rt_schedulable(tg, rt_period, rt_runtime))
 		ret = -EINVAL;
 	mutex_unlock(&rt_constraints_mutex);
 
 	return ret;
 }
-#else
+#else /* !CONFIG_RT_GROUP_SCHED */
 static int sched_rt_global_constraints(void)
 {
 	unsigned long flags;
@@ -8547,7 +8806,7 @@ static int sched_rt_global_constraints(void)
 
 	return 0;
 }
-#endif
+#endif /* CONFIG_RT_GROUP_SCHED */
 
 int sched_rt_handler(struct ctl_table *table, int write,
 		struct file *filp, void __user *buffer, size_t *lenp,
@@ -8655,7 +8914,7 @@ static u64 cpu_shares_read_u64(struct cgroup *cgrp, struct cftype *cft)
 
 	return (u64) tg->shares;
 }
-#endif
+#endif /* CONFIG_FAIR_GROUP_SCHED */
 
 #ifdef CONFIG_RT_GROUP_SCHED
 static int cpu_rt_runtime_write(struct cgroup *cgrp, struct cftype *cft,
@@ -8679,7 +8938,7 @@ static u64 cpu_rt_period_read_uint(struct cgroup *cgrp, struct cftype *cft)
 {
 	return sched_group_rt_period(cgroup_tg(cgrp));
 }
-#endif
+#endif /* CONFIG_RT_GROUP_SCHED */
 
 static struct cftype cpu_files[] = {
 #ifdef CONFIG_FAIR_GROUP_SCHED
diff --git a/kernel/sched_clock.c b/kernel/sched_clock.c
index ce05271..22ed55d 100644
--- a/kernel/sched_clock.c
+++ b/kernel/sched_clock.c
@@ -3,6 +3,9 @@
  *
  *  Copyright (C) 2008 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
  *
+ *  Updates and enhancements:
+ *    Copyright (C) 2008 Red Hat, Inc. Steven Rostedt <srostedt@redhat.com>
+ *
  * Based on code by:
  *   Ingo Molnar <mingo@redhat.com>
  *   Guillaume Chazarain <guichaz@gmail.com>
@@ -32,6 +35,11 @@
 
 #ifdef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
 
+#define MULTI_SHIFT 15
+/* Max is double, Min is 1/2 */
+#define MAX_MULTI (2LL << MULTI_SHIFT)
+#define MIN_MULTI (1LL << (MULTI_SHIFT-1))
+
 struct sched_clock_data {
 	/*
 	 * Raw spinlock - this is a special case: this might be called
@@ -40,11 +48,15 @@ struct sched_clock_data {
 	 */
 	raw_spinlock_t		lock;
 
-	unsigned long		prev_jiffies;
+	unsigned long		tick_jiffies;
 	u64			prev_raw;
 	u64			tick_raw;
 	u64			tick_gtod;
 	u64			clock;
+	s64			multi;
+#ifdef CONFIG_NO_HZ
+	int			check_max;
+#endif
 };
 
 static DEFINE_PER_CPU_SHARED_ALIGNED(struct sched_clock_data, sched_clock_data);
@@ -71,41 +83,91 @@ void sched_clock_init(void)
 		struct sched_clock_data *scd = cpu_sdc(cpu);
 
 		scd->lock = (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED;
-		scd->prev_jiffies = now_jiffies;
+		scd->tick_jiffies = now_jiffies;
 		scd->prev_raw = 0;
 		scd->tick_raw = 0;
 		scd->tick_gtod = ktime_now;
 		scd->clock = ktime_now;
+		scd->multi = 1 << MULTI_SHIFT;
+#ifdef CONFIG_NO_HZ
+		scd->check_max = 1;
+#endif
 	}
 
 	sched_clock_running = 1;
 }
 
+#ifdef CONFIG_NO_HZ
+/*
+ * The dynamic ticks makes the delta jiffies inaccurate. This
+ * prevents us from checking the maximum time update.
+ * Disable the maximum check during stopped ticks.
+ */
+void sched_clock_tick_stop(int cpu)
+{
+	struct sched_clock_data *scd = cpu_sdc(cpu);
+
+	scd->check_max = 0;
+}
+
+void sched_clock_tick_start(int cpu)
+{
+	struct sched_clock_data *scd = cpu_sdc(cpu);
+
+	scd->check_max = 1;
+}
+
+static int check_max(struct sched_clock_data *scd)
+{
+	return scd->check_max;
+}
+#else
+static int check_max(struct sched_clock_data *scd)
+{
+	return 1;
+}
+#endif /* CONFIG_NO_HZ */
+
 /*
  * update the percpu scd from the raw @now value
  *
  *  - filter out backward motion
  *  - use jiffies to generate a min,max window to clip the raw values
  */
-static void __update_sched_clock(struct sched_clock_data *scd, u64 now)
+static void __update_sched_clock(struct sched_clock_data *scd, u64 now, u64 *time)
 {
 	unsigned long now_jiffies = jiffies;
-	long delta_jiffies = now_jiffies - scd->prev_jiffies;
+	long delta_jiffies = now_jiffies - scd->tick_jiffies;
 	u64 clock = scd->clock;
 	u64 min_clock, max_clock;
 	s64 delta = now - scd->prev_raw;
 
 	WARN_ON_ONCE(!irqs_disabled());
-	min_clock = scd->tick_gtod + delta_jiffies * TICK_NSEC;
+
+	/*
+	 * At schedule tick the clock can be just under the gtod. We don't
+	 * want to push it too prematurely.
+	 */
+	min_clock = scd->tick_gtod + (delta_jiffies * TICK_NSEC);
+	if (min_clock > TICK_NSEC)
+		min_clock -= TICK_NSEC / 2;
 
 	if (unlikely(delta < 0)) {
 		clock++;
 		goto out;
 	}
 
-	max_clock = min_clock + TICK_NSEC;
+	/*
+	 * The clock must stay within a jiffie of the gtod.
+	 * But since we may be at the start of a jiffy or the end of one
+	 * we add another jiffy buffer.
+	 */
+	max_clock = scd->tick_gtod + (2 + delta_jiffies) * TICK_NSEC;
+
+	delta *= scd->multi;
+	delta >>= MULTI_SHIFT;
 
-	if (unlikely(clock + delta > max_clock)) {
+	if (unlikely(clock + delta > max_clock) && check_max(scd)) {
 		if (clock < max_clock)
 			clock = max_clock;
 		else
@@ -118,9 +180,12 @@ static void __update_sched_clock(struct sched_clock_data *scd, u64 now)
 	if (unlikely(clock < min_clock))
 		clock = min_clock;
 
-	scd->prev_raw = now;
-	scd->prev_jiffies = now_jiffies;
-	scd->clock = clock;
+	if (time)
+		*time = clock;
+	else {
+		scd->prev_raw = now;
+		scd->clock = clock;
+	}
 }
 
 static void lock_double_clock(struct sched_clock_data *data1,
@@ -160,25 +225,30 @@ u64 sched_clock_cpu(int cpu)
 		now -= my_scd->tick_raw;
 		now += scd->tick_raw;
 
-		now -= my_scd->tick_gtod;
-		now += scd->tick_gtod;
+		now += my_scd->tick_gtod;
+		now -= scd->tick_gtod;
 
 		__raw_spin_unlock(&my_scd->lock);
+
+		__update_sched_clock(scd, now, &clock);
+
+		__raw_spin_unlock(&scd->lock);
+
 	} else {
 		__raw_spin_lock(&scd->lock);
+		__update_sched_clock(scd, now, NULL);
+		clock = scd->clock;
+		__raw_spin_unlock(&scd->lock);
 	}
 
-	__update_sched_clock(scd, now);
-	clock = scd->clock;
-
-	__raw_spin_unlock(&scd->lock);
-
 	return clock;
 }
 
 void sched_clock_tick(void)
 {
 	struct sched_clock_data *scd = this_scd();
+	unsigned long now_jiffies = jiffies;
+	s64 mult, delta_gtod, delta_raw;
 	u64 now, now_gtod;
 
 	if (unlikely(!sched_clock_running))
@@ -186,18 +256,33 @@ void sched_clock_tick(void)
 
 	WARN_ON_ONCE(!irqs_disabled());
 
-	now = sched_clock();
 	now_gtod = ktime_to_ns(ktime_get());
+	now = sched_clock();
 
 	__raw_spin_lock(&scd->lock);
-	__update_sched_clock(scd, now);
+	__update_sched_clock(scd, now, NULL);
 	/*
 	 * update tick_gtod after __update_sched_clock() because that will
 	 * already observe 1 new jiffy; adding a new tick_gtod to that would
 	 * increase the clock 2 jiffies.
 	 */
+	delta_gtod = now_gtod - scd->tick_gtod;
+	delta_raw = now - scd->tick_raw;
+
+	if ((long)delta_raw > 0) {
+		mult = delta_gtod << MULTI_SHIFT;
+		do_div(mult, delta_raw);
+		scd->multi = mult;
+		if (scd->multi > MAX_MULTI)
+			scd->multi = MAX_MULTI;
+		else if (scd->multi < MIN_MULTI)
+			scd->multi = MIN_MULTI;
+	} else
+		scd->multi = 1 << MULTI_SHIFT;
+
 	scd->tick_raw = now;
 	scd->tick_gtod = now_gtod;
+	scd->tick_jiffies = now_jiffies;
 	__raw_spin_unlock(&scd->lock);
 }
 
@@ -227,6 +312,7 @@ void sched_clock_idle_wakeup_event(u64 delta_ns)
 	__raw_spin_lock(&scd->lock);
 	scd->prev_raw = now;
 	scd->clock += delta_ns;
+	scd->multi = 1 << MULTI_SHIFT;
 	__raw_spin_unlock(&scd->lock);
 
 	touch_softlockup_watchdog();
@@ -244,3 +330,16 @@ unsigned long long __attribute__((weak)) sched_clock(void)
 {
 	return (unsigned long long)jiffies * (NSEC_PER_SEC / HZ);
 }
+
+unsigned long long cpu_clock(int cpu)
+{
+	unsigned long long clock;
+	unsigned long flags;
+
+	local_irq_save(flags);
+	clock = sched_clock_cpu(cpu);
+	local_irq_restore(flags);
+
+	return clock;
+}
+EXPORT_SYMBOL_GPL(cpu_clock);
diff --git a/kernel/sched_cpupri.c b/kernel/sched_cpupri.c
new file mode 100644
index 0000000..52154fe
--- /dev/null
+++ b/kernel/sched_cpupri.c
@@ -0,0 +1,174 @@
+/*
+ *  kernel/sched_cpupri.c
+ *
+ *  CPU priority management
+ *
+ *  Copyright (C) 2007-2008 Novell
+ *
+ *  Author: Gregory Haskins <ghaskins@novell.com>
+ *
+ *  This code tracks the priority of each CPU so that global migration
+ *  decisions are easy to calculate.  Each CPU can be in a state as follows:
+ *
+ *                 (INVALID), IDLE, NORMAL, RT1, ... RT99
+ *
+ *  going from the lowest priority to the highest.  CPUs in the INVALID state
+ *  are not eligible for routing.  The system maintains this state with
+ *  a 2 dimensional bitmap (the first for priority class, the second for cpus
+ *  in that class).  Therefore a typical application without affinity
+ *  restrictions can find a suitable CPU with O(1) complexity (e.g. two bit
+ *  searches).  For tasks with affinity restrictions, the algorithm has a
+ *  worst case complexity of O(min(102, nr_domcpus)), though the scenario that
+ *  yields the worst case search is fairly contrived.
+ *
+ *  This program is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU General Public License
+ *  as published by the Free Software Foundation; version 2
+ *  of the License.
+ */
+
+#include "sched_cpupri.h"
+
+/* Convert between a 140 based task->prio, and our 102 based cpupri */
+static int convert_prio(int prio)
+{
+	int cpupri;
+
+	if (prio == CPUPRI_INVALID)
+		cpupri = CPUPRI_INVALID;
+	else if (prio == MAX_PRIO)
+		cpupri = CPUPRI_IDLE;
+	else if (prio >= MAX_RT_PRIO)
+		cpupri = CPUPRI_NORMAL;
+	else
+		cpupri = MAX_RT_PRIO - prio + 1;
+
+	return cpupri;
+}
+
+#define for_each_cpupri_active(array, idx)
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[git pull] scheduler changes for v2.6.27, Ingo Molnar, (Mon Jul 14, 9:54 am)