Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler changes from Ingo Molnar:
 "The main changes in this development cycle were:

   - full dynticks preparatory work by Frederic Weisbecker

   - factor out the cpu time accounting code better, by Li Zefan

   - multi-CPU load balancer cleanups and improvements by Joonsoo Kim

   - various smaller fixes and cleanups"

* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (45 commits)
  sched: Fix init NOHZ_IDLE flag
  sched: Prevent to re-select dst-cpu in load_balance()
  sched: Rename load_balance_tmpmask to load_balance_mask
  sched: Move up affinity check to mitigate useless redoing overhead
  sched: Don't consider other cpus in our group in case of NEWLY_IDLE
  sched: Explicitly cpu_idle_type checking in rebalance_domains()
  sched: Change position of resched_cpu() in load_balance()
  sched: Fix wrong rq's runnable_avg update with rt tasks
  sched: Document task_struct::personality field
  sched/cpuacct/UML: Fix header file dependency bug on the UML build
  cgroup: Kill subsys.active flag
  sched/cpuacct: No need to check subsys active state
  sched/cpuacct: Initialize cpuacct subsystem earlier
  sched/cpuacct: Initialize root cpuacct earlier
  sched/cpuacct: Allocate per_cpu cpuusage for root cpuacct statically
  sched/cpuacct: Clean up cpuacct.h
  sched/cpuacct: Remove redundant NULL checks in cpuacct_acount_field()
  sched/cpuacct: Remove redundant NULL checks in cpuacct_charge()
  sched/cpuacct: Add cpuacct_acount_field()
  sched/cpuacct: Add cpuacct_init()
  ...

20 files changed, 834 insertions, 709 deletions

diff --git a/arch/x86/include/asm/context_tracking.h b/arch/x86/include/asm/context_tracking.h
index 1616562683e9..1fe49704b146 100644
--- a/arch/x86/include/asm/context_tracking.h
+++ b/arch/x86/include/asm/context_tracking.h
@@ -1,31 +1,10 @@
 #ifndef _ASM_X86_CONTEXT_TRACKING_H
 #define _ASM_X86_CONTEXT_TRACKING_H
 
-#ifndef __ASSEMBLY__
-#include <linux/context_tracking.h>
-#include <asm/ptrace.h>
-
-static inline void exception_enter(struct pt_regs *regs)
-{
-	user_exit();
-}
-
-static inline void exception_exit(struct pt_regs *regs)
-{
-#ifdef CONFIG_CONTEXT_TRACKING
-	if (user_mode(regs))
-		user_enter();
-#endif
-}
-
-#else /* __ASSEMBLY__ */
-
 #ifdef CONFIG_CONTEXT_TRACKING
 # define SCHEDULE_USER call schedule_user
 #else
 # define SCHEDULE_USER call schedule
 #endif
 
-#endif /* !__ASSEMBLY__ */
-
 #endif
diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index b686a904d7c3..cd6d9a5a42f6 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -20,6 +20,7 @@
  *   Authors: Anthony Liguori <aliguori@us.ibm.com>
  */
 
+#include <linux/context_tracking.h>
 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/kvm_para.h>
@@ -43,7 +44,6 @@
 #include <asm/apicdef.h>
 #include <asm/hypervisor.h>
 #include <asm/kvm_guest.h>
-#include <asm/context_tracking.h>
 
 static int kvmapf = 1;
 
@@ -254,16 +254,18 @@ EXPORT_SYMBOL_GPL(kvm_read_and_reset_pf_reason);
 dotraplinkage void __kprobes
 do_async_page_fault(struct pt_regs *regs, unsigned long error_code)
 {
+	enum ctx_state prev_state;
+
 	switch (kvm_read_and_reset_pf_reason()) {
 	default:
 		do_page_fault(regs, error_code);
 		break;
 	case KVM_PV_REASON_PAGE_NOT_PRESENT:
 		/* page is swapped out by the host. */
-		exception_enter(regs);
+		prev_state = exception_enter();
 		exit_idle();
 		kvm_async_pf_task_wait((u32)read_cr2());
-		exception_exit(regs);
+		exception_exit(prev_state);
 		break;
 	case KVM_PV_REASON_PAGE_READY:
 		rcu_irq_enter();
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index 68bda7a84159..ff6d2271cbe2 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -12,6 +12,7 @@
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
+#include <linux/context_tracking.h>
 #include <linux/interrupt.h>
 #include <linux/kallsyms.h>
 #include <linux/spinlock.h>
@@ -55,8 +56,6 @@
 #include <asm/i387.h>
 #include <asm/fpu-internal.h>
 #include <asm/mce.h>
-#include <asm/context_tracking.h>
-
 #include <asm/mach_traps.h>
 
 #ifdef CONFIG_X86_64
@@ -176,34 +175,38 @@ do_trap(int trapnr, int signr, char *str, struct pt_regs *regs,
 #define DO_ERROR(trapnr, signr, str, name)				\
 dotraplinkage void do_##name(struct pt_regs *regs, long error_code)	\
 {									\
-	exception_enter(regs);						\
+	enum ctx_state prev_state;					\
+									\
+	prev_state = exception_enter();					\
 	if (notify_die(DIE_TRAP, str, regs, error_code,			\
 			trapnr, signr) == NOTIFY_STOP) {		\
-		exception_exit(regs);					\
+		exception_exit(prev_state);				\
 		return;							\
 	}								\
 	conditional_sti(regs);						\
 	do_trap(trapnr, signr, str, regs, error_code, NULL);		\
-	exception_exit(regs);						\
+	exception_exit(prev_state);					\
 }
 
 #define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr)		\
 dotraplinkage void do_##name(struct pt_regs *regs, long error_code)	\
 {									\
 	siginfo_t info;							\
+	enum ctx_state prev_state;					\
+									\
 	info.si_signo = signr;						\
 	info.si_errno = 0;						\
 	info.si_code = sicode;						\
 	info.si_addr = (void __user *)siaddr;				\
-	exception_enter(regs);						\
+	prev_state = exception_enter();					\
 	if (notify_die(DIE_TRAP, str, regs, error_code,			\
 			trapnr, signr) == NOTIFY_STOP) {		\
-		exception_exit(regs);					\
+		exception_exit(prev_state);				\
 		return;							\
 	}								\
 	conditional_sti(regs);						\
 	do_trap(trapnr, signr, str, regs, error_code, &info);		\
-	exception_exit(regs);						\
+	exception_exit(prev_state);					\
 }
 
 DO_ERROR_INFO(X86_TRAP_DE, SIGFPE, "divide error", divide_error, FPE_INTDIV,
@@ -226,14 +229,16 @@ DO_ERROR_INFO(X86_TRAP_AC, SIGBUS, "alignment check", alignment_check,
 /* Runs on IST stack */
 dotraplinkage void do_stack_segment(struct pt_regs *regs, long error_code)
 {
-	exception_enter(regs);
+	enum ctx_state prev_state;
+
+	prev_state = exception_enter();
 	if (notify_die(DIE_TRAP, "stack segment", regs, error_code,
 		       X86_TRAP_SS, SIGBUS) != NOTIFY_STOP) {
 		preempt_conditional_sti(regs);
 		do_trap(X86_TRAP_SS, SIGBUS, "stack segment", regs, error_code, NULL);
 		preempt_conditional_cli(regs);
 	}
-	exception_exit(regs);
+	exception_exit(prev_state);
 }
 
 dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code)
@@ -241,7 +246,7 @@ dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code)
 	static const char str[] = "double fault";
 	struct task_struct *tsk = current;
 
-	exception_enter(regs);
+	exception_enter();
 	/* Return not checked because double check cannot be ignored */
 	notify_die(DIE_TRAP, str, regs, error_code, X86_TRAP_DF, SIGSEGV);
 
@@ -261,8 +266,9 @@ dotraplinkage void __kprobes
 do_general_protection(struct pt_regs *regs, long error_code)
 {
 	struct task_struct *tsk;
+	enum ctx_state prev_state;
 
-	exception_enter(regs);
+	prev_state = exception_enter();
 	conditional_sti(regs);
 
 #ifdef CONFIG_X86_32
@@ -300,12 +306,14 @@ do_general_protection(struct pt_regs *regs, long error_code)
 
 	force_sig(SIGSEGV, tsk);
 exit:
-	exception_exit(regs);
+	exception_exit(prev_state);
 }
 
 /* May run on IST stack. */
 dotraplinkage void __kprobes notrace do_int3(struct pt_regs *regs, long error_code)
 {
+	enum ctx_state prev_state;
+
 #ifdef CONFIG_DYNAMIC_FTRACE
 	/*
 	 * ftrace must be first, everything else may cause a recursive crash.
@@ -315,7 +323,7 @@ dotraplinkage void __kprobes notrace do_int3(struct pt_regs *regs, long error_co
 	    ftrace_int3_handler(regs))
 		return;
 #endif
-	exception_enter(regs);
+	prev_state = exception_enter();
 #ifdef CONFIG_KGDB_LOW_LEVEL_TRAP
 	if (kgdb_ll_trap(DIE_INT3, "int3", regs, error_code, X86_TRAP_BP,
 				SIGTRAP) == NOTIFY_STOP)
@@ -336,7 +344,7 @@ dotraplinkage void __kprobes notrace do_int3(struct pt_regs *regs, long error_co
 	preempt_conditional_cli(regs);
 	debug_stack_usage_dec();
 exit:
-	exception_exit(regs);
+	exception_exit(prev_state);
 }
 
 #ifdef CONFIG_X86_64
@@ -393,11 +401,12 @@ asmlinkage __kprobes struct pt_regs *sync_regs(struct pt_regs *eregs)
 dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code)
 {
 	struct task_struct *tsk = current;
+	enum ctx_state prev_state;
 	int user_icebp = 0;
 	unsigned long dr6;
 	int si_code;
 
-	exception_enter(regs);
+	prev_state = exception_enter();
 
 	get_debugreg(dr6, 6);
 
@@ -467,7 +476,7 @@ dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code)
 	debug_stack_usage_dec();
 
 exit:
-	exception_exit(regs);
+	exception_exit(prev_state);
 }
 
 /*
@@ -561,17 +570,21 @@ void math_error(struct pt_regs *regs, int error_code, int trapnr)
 
 dotraplinkage void do_coprocessor_error(struct pt_regs *regs, long error_code)
 {
-	exception_enter(regs);
+	enum ctx_state prev_state;
+
+	prev_state = exception_enter();
 	math_error(regs, error_code, X86_TRAP_MF);
-	exception_exit(regs);
+	exception_exit(prev_state);
 }
 
 dotraplinkage void
 do_simd_coprocessor_error(struct pt_regs *regs, long error_code)
 {
-	exception_enter(regs);
+	enum ctx_state prev_state;
+
+	prev_state = exception_enter();
 	math_error(regs, error_code, X86_TRAP_XF);
-	exception_exit(regs);
+	exception_exit(prev_state);
 }
 
 dotraplinkage void
@@ -639,7 +652,9 @@ EXPORT_SYMBOL_GPL(math_state_restore);
 dotraplinkage void __kprobes
 do_device_not_available(struct pt_regs *regs, long error_code)
 {
-	exception_enter(regs);
+	enum ctx_state prev_state;
+
+	prev_state = exception_enter();
 	BUG_ON(use_eager_fpu());
 
 #ifdef CONFIG_MATH_EMULATION
@@ -650,7 +665,7 @@ do_device_not_available(struct pt_regs *regs, long error_code)
 
 		info.regs = regs;
 		math_emulate(&info);
-		exception_exit(regs);
+		exception_exit(prev_state);
 		return;
 	}
 #endif
@@ -658,15 +673,16 @@ do_device_not_available(struct pt_regs *regs, long error_code)
 #ifdef CONFIG_X86_32
 	conditional_sti(regs);
 #endif
-	exception_exit(regs);
+	exception_exit(prev_state);
 }
 
 #ifdef CONFIG_X86_32
 dotraplinkage void do_iret_error(struct pt_regs *regs, long error_code)
 {
 	siginfo_t info;
+	enum ctx_state prev_state;
 
-	exception_enter(regs);
+	prev_state = exception_enter();
 	local_irq_enable();
 
 	info.si_signo = SIGILL;
@@ -678,7 +694,7 @@ dotraplinkage void do_iret_error(struct pt_regs *regs, long error_code)
 		do_trap(X86_TRAP_IRET, SIGILL, "iret exception", regs, error_code,
 			&info);
 	}
-	exception_exit(regs);
+	exception_exit(prev_state);
 }
 #endif
 
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 0e883364abb5..022a9a0a3c63 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -13,12 +13,12 @@
 #include <linux/perf_event.h>		/* perf_sw_event		*/
 #include <linux/hugetlb.h>		/* hstate_index_to_shift	*/
 #include <linux/prefetch.h>		/* prefetchw			*/
+#include <linux/context_tracking.h>	/* exception_enter(), ...	*/
 
 #include <asm/traps.h>			/* dotraplinkage, ...		*/
 #include <asm/pgalloc.h>		/* pgd_*(), ...			*/
 #include <asm/kmemcheck.h>		/* kmemcheck_*(), ...		*/
 #include <asm/fixmap.h>			/* VSYSCALL_START		*/
-#include <asm/context_tracking.h>	/* exception_enter(), ...	*/
 
 /*
  * Page fault error code bits:
@@ -1224,7 +1224,9 @@ good_area:
 dotraplinkage void __kprobes
 do_page_fault(struct pt_regs *regs, unsigned long error_code)
 {
-	exception_enter(regs);
+	enum ctx_state prev_state;
+
+	prev_state = exception_enter();
 	__do_page_fault(regs, error_code);
-	exception_exit(regs);
+	exception_exit(prev_state);
 }
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index d86e215ca2b8..646ab9d15e42 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -586,7 +586,6 @@ struct cgroup_subsys {
 	void (*bind)(struct cgroup *root);
 
 	int subsys_id;
-	int active;
 	int disabled;
 	int early_init;
 	/*
diff --git a/include/linux/context_tracking.h b/include/linux/context_tracking.h
index b28d161c1091..365f4a61bf04 100644
--- a/include/linux/context_tracking.h
+++ b/include/linux/context_tracking.h
@@ -1,9 +1,9 @@
 #ifndef _LINUX_CONTEXT_TRACKING_H
 #define _LINUX_CONTEXT_TRACKING_H
 
-#ifdef CONFIG_CONTEXT_TRACKING
 #include <linux/sched.h>
 #include <linux/percpu.h>
+#include <asm/ptrace.h>
 
 struct context_tracking {
 	/*
@@ -13,12 +13,13 @@ struct context_tracking {
 	 * may be further optimized using static keys.
 	 */
 	bool active;
-	enum {
+	enum ctx_state {
 		IN_KERNEL = 0,
 		IN_USER,
 	} state;
 };
 
+#ifdef CONFIG_CONTEXT_TRACKING
 DECLARE_PER_CPU(struct context_tracking, context_tracking);
 
 static inline bool context_tracking_in_user(void)
@@ -33,12 +34,31 @@ static inline bool context_tracking_active(void)
 
 extern void user_enter(void);
 extern void user_exit(void);
+
+static inline enum ctx_state exception_enter(void)
+{
+	enum ctx_state prev_ctx;
+
+	prev_ctx = this_cpu_read(context_tracking.state);
+	user_exit();
+
+	return prev_ctx;
+}
+
+static inline void exception_exit(enum ctx_state prev_ctx)
+{
+	if (prev_ctx == IN_USER)
+		user_enter();
+}
+
 extern void context_tracking_task_switch(struct task_struct *prev,
 					 struct task_struct *next);
 #else
 static inline bool context_tracking_in_user(void) { return false; }
 static inline void user_enter(void) { }
 static inline void user_exit(void) { }
+static inline enum ctx_state exception_enter(void) { return 0; }
+static inline void exception_exit(enum ctx_state prev_ctx) { }
 static inline void context_tracking_task_switch(struct task_struct *prev,
 						struct task_struct *next) { }
 #endif /* !CONFIG_CONTEXT_TRACKING */
diff --git a/include/linux/math64.h b/include/linux/math64.h
index b8ba85544721..931a619407bf 100644
--- a/include/linux/math64.h
+++ b/include/linux/math64.h
@@ -30,6 +30,15 @@ static inline s64 div_s64_rem(s64 dividend, s32 divisor, s32 *remainder)
 }
 
 /**
+ * div64_u64_rem - unsigned 64bit divide with 64bit divisor
+ */
+static inline u64 div64_u64_rem(u64 dividend, u64 divisor, u64 *remainder)
+{
+	*remainder = dividend % divisor;
+	return dividend / divisor;
+}
+
+/**
  * div64_u64 - unsigned 64bit divide with 64bit divisor
  */
 static inline u64 div64_u64(u64 dividend, u64 divisor)
@@ -61,8 +70,16 @@ static inline u64 div_u64_rem(u64 dividend, u32 divisor, u32 *remainder)
 extern s64 div_s64_rem(s64 dividend, s32 divisor, s32 *remainder);
 #endif
 
+#ifndef div64_u64_rem
+extern u64 div64_u64_rem(u64 dividend, u64 divisor, u64 *remainder);
+#endif
+
 #ifndef div64_u64
-extern u64 div64_u64(u64 dividend, u64 divisor);
+static inline u64 div64_u64(u64 dividend, u64 divisor)
+{
+	u64 remainder;
+	return div64_u64_rem(dividend, divisor, &remainder);
+}
 #endif
 
 #ifndef div64_s64
diff --git a/include/linux/sched.h b/include/linux/sched.h
index bcbc30397f23..01c7d85bcaa7 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -127,18 +127,6 @@ extern void proc_sched_show_task(struct task_struct *p, struct seq_file *m);
 extern void proc_sched_set_task(struct task_struct *p);
 extern void
 print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq);
-#else
-static inline void
-proc_sched_show_task(struct task_struct *p, struct seq_file *m)
-{
-}
-static inline void proc_sched_set_task(struct task_struct *p)
-{
-}
-static inline void
-print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
-{
-}
 #endif
 
 /*
@@ -570,7 +558,7 @@ struct signal_struct {
 	cputime_t utime, stime, cutime, cstime;
 	cputime_t gtime;
 	cputime_t cgtime;
-#ifndef CONFIG_VIRT_CPU_ACCOUNTING
+#ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
 	struct cputime prev_cputime;
 #endif
 	unsigned long nvcsw, nivcsw, cnvcsw, cnivcsw;
@@ -768,31 +756,6 @@ enum cpu_idle_type {
 };
 
 /*
- * Increase resolution of nice-level calculations for 64-bit architectures.
- * The extra resolution improves shares distribution and load balancing of
- * low-weight task groups (eg. nice +19 on an autogroup), deeper taskgroup
- * hierarchies, especially on larger systems. This is not a user-visible change
- * and does not change the user-interface for setting shares/weights.
- *
- * We increase resolution only if we have enough bits to allow this increased
- * resolution (i.e. BITS_PER_LONG > 32). The costs for increasing resolution
- * when BITS_PER_LONG <= 32 are pretty high and the returns do not justify the
- * increased costs.
- */
-#if 0 /* BITS_PER_LONG > 32 -- currently broken: it increases power usage under light load  */
-# define SCHED_LOAD_RESOLUTION	10
-# define scale_load(w)		((w) << SCHED_LOAD_RESOLUTION)
-# define scale_load_down(w)	((w) >> SCHED_LOAD_RESOLUTION)
-#else
-# define SCHED_LOAD_RESOLUTION	0
-# define scale_load(w)		(w)
-# define scale_load_down(w)	(w)
-#endif
-
-#define SCHED_LOAD_SHIFT	(10 + SCHED_LOAD_RESOLUTION)
-#define SCHED_LOAD_SCALE	(1L << SCHED_LOAD_SHIFT)
-
-/*
  * Increase resolution of cpu_power calculations
  */
 #define SCHED_POWER_SHIFT	10
@@ -817,62 +780,6 @@ enum cpu_idle_type {
 
 extern int __weak arch_sd_sibiling_asym_packing(void);
 
-struct sched_group_power {
-	atomic_t ref;
-	/*
-	 * CPU power of this group, SCHED_LOAD_SCALE being max power for a
-	 * single CPU.
-	 */
-	unsigned int power, power_orig;
-	unsigned long next_update;
-	/*
-	 * Number of busy cpus in this group.
-	 */
-	atomic_t nr_busy_cpus;
-
-	unsigned long cpumask[0]; /* iteration mask */
-};
-
-struct sched_group {
-	struct sched_group *next;	/* Must be a circular list */
-	atomic_t ref;
-
-	unsigned int group_weight;
-	struct sched_group_power *sgp;
-
-	/*
-	 * The CPUs this group covers.
-	 *
-	 * NOTE: this field is variable length. (Allocated dynamically
-	 * by attaching extra space to the end of the structure,
-	 * depending on how many CPUs the kernel has booted up with)
-	 */
-	unsigned long cpumask[0];
-};
-
-static inline struct cpumask *sched_group_cpus(struct sched_group *sg)
-{
-	return to_cpumask(sg->cpumask);
-}
-
-/*
- * cpumask masking which cpus in the group are allowed to iterate up the domain
- * tree.
- */
-static inline struct cpumask *sched_group_mask(struct sched_group *sg)
-{
-	return to_cpumask(sg->sgp->cpumask);
-}
-
-/**
- * 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));
-}
-
 struct sched_domain_attr {
 	int relax_domain_level;
 };
@@ -883,6 +790,8 @@ struct sched_domain_attr {
 
 extern int sched_domain_level_max;
 
+struct sched_group;
+
 struct sched_domain {
 	/* These fields must be setup */
 	struct sched_domain *parent;	/* top domain must be null terminated */
@@ -899,6 +808,8 @@ struct sched_domain {
 	unsigned int wake_idx;
 	unsigned int forkexec_idx;
 	unsigned int smt_gain;
+
+	int nohz_idle;			/* NOHZ IDLE status */
 	int flags;			/* See SD_* */
 	int level;
 
@@ -971,18 +882,6 @@ extern void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[],
 cpumask_var_t *alloc_sched_domains(unsigned int ndoms);
 void free_sched_domains(cpumask_var_t doms[], unsigned int ndoms);
 
-/* Test a flag in parent sched domain */
-static inline int test_sd_parent(struct sched_domain *sd, int flag)
-{
-	if (sd->parent && (sd->parent->flags & flag))
-		return 1;
-
-	return 0;
-}
-
-unsigned long default_scale_freq_power(struct sched_domain *sd, int cpu);
-unsigned long default_scale_smt_power(struct sched_domain *sd, int cpu);
-
 bool cpus_share_cache(int this_cpu, int that_cpu);
 
 #else /* CONFIG_SMP */
@@ -1017,72 +916,6 @@ struct mempolicy;
 struct pipe_inode_info;
 struct uts_namespace;
 
-struct rq;
-struct sched_domain;
-
-/*
- * wake flags
- */
-#define WF_SYNC		0x01		/* waker goes to sleep after wakup */
-#define WF_FORK		0x02		/* child wakeup after fork */
-#define WF_MIGRATED	0x04		/* internal use, task got migrated */
-
-#define ENQUEUE_WAKEUP		1
-#define ENQUEUE_HEAD		2
-#ifdef CONFIG_SMP
-#define ENQUEUE_WAKING		4	/* sched_class::task_waking was called */
-#else
-#define ENQUEUE_WAKING		0
-#endif
-
-#define DEQUEUE_SLEEP		1
-
-struct sched_class {
-	const struct sched_class *next;
-
-	void (*enqueue_task) (struct rq *rq, struct task_struct *p, int flags);
-	void (*dequeue_task) (struct rq *rq, struct task_struct *p, int flags);
-	void (*yield_task) (struct rq *rq);
-	bool (*yield_to_task) (struct rq *rq, struct task_struct *p, bool preempt);
-
-	void (*check_preempt_curr) (struct rq *rq, struct task_struct *p, int flags);
-
-	struct task_struct * (*pick_next_task) (struct rq *rq);
-	void (*put_prev_task) (struct rq *rq, struct task_struct *p);
-
-#ifdef CONFIG_SMP
-	int  (*select_task_rq)(struct task_struct *p, int sd_flag, int flags);
-	void (*migrate_task_rq)(struct task_struct *p, int next_cpu);
-
-	void (*pre_schedule) (struct rq *this_rq, struct task_struct *task);
-	void (*post_schedule) (struct rq *this_rq);
-	void (*task_waking) (struct task_struct *task);
-	void (*task_woken) (struct rq *this_rq, struct task_struct *task);
-
-	void (*set_cpus_allowed)(struct task_struct *p,
-				 const struct cpumask *newmask);
-
-	void (*rq_online)(struct rq *rq);
-	void (*rq_offline)(struct rq *rq);
-#endif
-
-	void (*set_curr_task) (struct rq *rq);
-	void (*task_tick) (struct rq *rq, struct task_struct *p, int queued);
-	void (*task_fork) (struct task_struct *p);
-
-	void (*switched_from) (struct rq *this_rq, struct task_struct *task);
-	void (*switched_to) (struct rq *this_rq, struct task_struct *task);
-	void (*prio_changed) (struct rq *this_rq, struct task_struct *task,
-			     int oldprio);
-
-	unsigned int (*get_rr_interval) (struct rq *rq,
-					 struct task_struct *task);
-
-#ifdef CONFIG_FAIR_GROUP_SCHED
-	void (*task_move_group) (struct task_struct *p, int on_rq);
-#endif
-};
-
 struct load_weight {
 	unsigned long weight, inv_weight;
 };
@@ -1274,8 +1107,10 @@ struct task_struct {
 	int exit_code, exit_signal;
 	int pdeath_signal;  /*  The signal sent when the parent dies  */
 	unsigned int jobctl;	/* JOBCTL_*, siglock protected */
-	/* ??? */
+
+	/* Used for emulating ABI behavior of previous Linux versions */
 	unsigned int personality;
+
 	unsigned did_exec:1;
 	unsigned in_execve:1;	/* Tell the LSMs that the process is doing an
 				 * execve */
@@ -1327,7 +1162,7 @@ struct task_struct {
 
 	cputime_t utime, stime, utimescaled, stimescaled;
 	cputime_t gtime;
-#ifndef CONFIG_VIRT_CPU_ACCOUNTING
+#ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
 	struct cputime prev_cputime;
 #endif
 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
@@ -2681,28 +2516,7 @@ extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
 extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
 
 #ifdef CONFIG_CGROUP_SCHED
-
 extern struct task_group root_task_group;
-
-extern struct task_group *sched_create_group(struct task_group *parent);
-extern void sched_online_group(struct task_group *tg,
-			       struct task_group *parent);
-extern void sched_destroy_group(struct task_group *tg);
-extern void sched_offline_group(struct task_group *tg);
-extern void sched_move_task(struct task_struct *tsk);
-#ifdef CONFIG_FAIR_GROUP_SCHED
-extern int sched_group_set_shares(struct task_group *tg, unsigned long shares);
-extern unsigned long sched_group_shares(struct task_group *tg);
-#endif
-#ifdef CONFIG_RT_GROUP_SCHED
-extern int sched_group_set_rt_runtime(struct task_group *tg,
-				      long rt_runtime_us);
-extern long sched_group_rt_runtime(struct task_group *tg);
-extern int sched_group_set_rt_period(struct task_group *tg,
-				      long rt_period_us);
-extern long sched_group_rt_period(struct task_group *tg);
-extern int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk);
-#endif
 #endif /* CONFIG_CGROUP_SCHED */
 
 extern int task_can_switch_user(struct user_struct *up,
diff --git a/init/Kconfig b/init/Kconfig
index 71bb9e73011a..4367e1379002 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -505,6 +505,7 @@ config RCU_USER_QS
 config CONTEXT_TRACKING_FORCE
 	bool "Force context tracking"
 	depends on CONTEXT_TRACKING
+	default CONTEXT_TRACKING
 	help
 	  Probe on user/kernel boundaries by default in order to
 	  test the features that rely on it such as userspace RCU extended
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index eeb7e49946b2..d3abce2d6455 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -4380,7 +4380,6 @@ static void __init cgroup_init_subsys(struct cgroup_subsys *ss)
 	 * need to invoke fork callbacks here. */
 	BUG_ON(!list_empty(&init_task.tasks));
 
-	ss->active = 1;
 	BUG_ON(online_css(ss, dummytop));
 
 	mutex_unlock(&cgroup_mutex);
@@ -4485,7 +4484,6 @@ int __init_or_module cgroup_load_subsys(struct cgroup_subsys *ss)
 	}
 	write_unlock(&css_set_lock);
 
-	ss->active = 1;
 	ret = online_css(ss, dummytop);
 	if (ret)
 		goto err_unload;
@@ -4526,7 +4524,6 @@ void cgroup_unload_subsys(struct cgroup_subsys *ss)
 	mutex_lock(&cgroup_mutex);
 
 	offline_css(ss, dummytop);
-	ss->active = 0;
 
 	if (ss->use_id)
 		idr_destroy(&ss->idr);
diff --git a/kernel/fork.c b/kernel/fork.c
index 1766d324d5e3..339f60dfd62b 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1233,7 +1233,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
 
 	p->utime = p->stime = p->gtime = 0;
 	p->utimescaled = p->stimescaled = 0;
-#ifndef CONFIG_VIRT_CPU_ACCOUNTING
+#ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
 	p->prev_cputime.utime = p->prev_cputime.stime = 0;
 #endif
 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
diff --git a/kernel/sched/Makefile b/kernel/sched/Makefile
index f06d249e103b..deaf90e4a1de 100644
--- a/kernel/sched/Makefile
+++ b/kernel/sched/Makefile
@@ -16,3 +16,4 @@ obj-$(CONFIG_SMP) += cpupri.o
 obj-$(CONFIG_SCHED_AUTOGROUP) += auto_group.o
 obj-$(CONFIG_SCHEDSTATS) += stats.o
 obj-$(CONFIG_SCHED_DEBUG) += debug.o
+obj-$(CONFIG_CGROUP_CPUACCT) += cpuacct.o
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index d8285eb0cde6..ebdb19541218 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -1288,8 +1288,8 @@ static void ttwu_activate(struct rq *rq, struct task_struct *p, int en_flags)
 static void
 ttwu_do_wakeup(struct rq *rq, struct task_struct *p, int wake_flags)
 {
-	trace_sched_wakeup(p, true);
 	check_preempt_curr(rq, p, wake_flags);
+	trace_sched_wakeup(p, true);
 
 	p->state = TASK_RUNNING;
 #ifdef CONFIG_SMP
@@ -3039,11 +3039,13 @@ EXPORT_SYMBOL(preempt_schedule);
 asmlinkage void __sched preempt_schedule_irq(void)
 {
 	struct thread_info *ti = current_thread_info();
+	enum ctx_state prev_state;
 
 	/* Catch callers which need to be fixed */
 	BUG_ON(ti->preempt_count || !irqs_disabled());
 
-	user_exit();
+	prev_state = exception_enter();
+
 	do {
 		add_preempt_count(PREEMPT_ACTIVE);
 		local_irq_enable();
@@ -3057,6 +3059,8 @@ asmlinkage void __sched preempt_schedule_irq(void)
 		 */
 		barrier();
 	} while (need_resched());
+
+	exception_exit(prev_state);
 }
 
 #endif /* CONFIG_PREEMPT */
@@ -6204,7 +6208,7 @@ static void sched_init_numa(void)
 	 * 'level' contains the number of unique distances, excluding the
 	 * identity distance node_distance(i,i).
 	 *
-	 * The sched_domains_nume_distance[] array includes the actual distance
+	 * The sched_domains_numa_distance[] array includes the actual distance
 	 * numbers.
 	 */
 
@@ -6817,11 +6821,15 @@ int in_sched_functions(unsigned long addr)
 }
 
 #ifdef CONFIG_CGROUP_SCHED
+/*
+ * Default task group.
+ * Every task in system belongs to this group at bootup.
+ */
 struct task_group root_task_group;
 LIST_HEAD(task_groups);
 #endif
 
-DECLARE_PER_CPU(cpumask_var_t, load_balance_tmpmask);
+DECLARE_PER_CPU(cpumask_var_t, load_balance_mask);
 
 void __init sched_init(void)
 {
@@ -6858,7 +6866,7 @@ void __init sched_init(void)
 #endif /* CONFIG_RT_GROUP_SCHED */
 #ifdef CONFIG_CPUMASK_OFFSTACK
 		for_each_possible_cpu(i) {
-			per_cpu(load_balance_tmpmask, i) = (void *)ptr;
+			per_cpu(load_balance_mask, i) = (void *)ptr;
 			ptr += cpumask_size();
 		}
 #endif /* CONFIG_CPUMASK_OFFSTACK */
@@ -6884,12 +6892,6 @@ void __init sched_init(void)
 
 #endif /* CONFIG_CGROUP_SCHED */
 
-#ifdef CONFIG_CGROUP_CPUACCT
-	root_cpuacct.cpustat = &kernel_cpustat;
-	root_cpuacct.cpuusage = alloc_percpu(u64);
-	/* Too early, not expected to fail */
-	BUG_ON(!root_cpuacct.cpuusage);
-#endif
 	for_each_possible_cpu(i) {
 		struct rq *rq;
 
@@ -7411,7 +7413,7 @@ unlock:
 	return err;
 }
 
-int sched_group_set_rt_runtime(struct task_group *tg, long rt_runtime_us)
+static int sched_group_set_rt_runtime(struct task_group *tg, long rt_runtime_us)
 {
 	u64 rt_runtime, rt_period;
 
@@ -7423,7 +7425,7 @@ int sched_group_set_rt_runtime(struct task_group *tg, long rt_runtime_us)
 	return tg_set_rt_bandwidth(tg, rt_period, rt_runtime);
 }
 
-long sched_group_rt_runtime(struct task_group *tg)
+static long sched_group_rt_runtime(struct task_group *tg)
 {
 	u64 rt_runtime_us;
 
@@ -7435,7 +7437,7 @@ long sched_group_rt_runtime(struct task_group *tg)
 	return rt_runtime_us;
 }
 
-int sched_group_set_rt_period(struct task_group *tg, long rt_period_us)
+static int sched_group_set_rt_period(struct task_group *tg, long rt_period_us)
 {
 	u64 rt_runtime, rt_period;
 
@@ -7448,7 +7450,7 @@ int sched_group_set_rt_period(struct task_group *tg, long rt_period_us)
 	return tg_set_rt_bandwidth(tg, rt_period, rt_runtime);
 }
 
-long sched_group_rt_period(struct task_group *tg)
+static long sched_group_rt_period(struct task_group *tg)
 {
 	u64 rt_period_us;