Commit bf967be3 authored by Ingo Molnar's avatar Ingo Molnar
Browse files

Merge branch 'timers/nohz' of... 

Merge branch 'timers/nohz' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks

 into timers/nohz

Pull nohz-full enabling patches from Frederic Weisbecker:

  " This handles perf and CPUs that get more than one task and fix posix cpu timers
    handling.

    This can finally stop the tick."

Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parents a166fcf0 67826eae

include/linux/perf_event.h

+6 −0
Original line number Diff line number Diff line
@@ -799,6 +799,12 @@ static inline int __perf_event_disable(void *info) { return -1; } 
static inline void perf_event_task_tick(void)				{ }

#endif



#if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_NO_HZ_FULL)

extern bool perf_event_can_stop_tick(void);

#else

static inline bool perf_event_can_stop_tick(void)			{ return true; }

#endif



#define perf_output_put(handle, x) perf_output_copy((handle), &(x), sizeof(x))



/*

include/linux/sched.h

+6 −0
Original line number Diff line number Diff line
@@ -1856,6 +1856,12 @@ extern void wake_up_nohz_cpu(int cpu); 
static inline void wake_up_nohz_cpu(int cpu) { }

#endif



#ifdef CONFIG_NO_HZ_FULL

extern bool sched_can_stop_tick(void);

#else

static inline bool sched_can_stop_tick(void) { return false; }

#endif



#ifdef CONFIG_SCHED_AUTOGROUP

extern void sched_autogroup_create_attach(struct task_struct *p);

extern void sched_autogroup_detach(struct task_struct *p);

include/linux/tick.h

+4 −0
Original line number Diff line number Diff line
@@ -160,13 +160,17 @@ static inline u64 get_cpu_iowait_time_us(int cpu, u64 *unused) { return -1; } 
#ifdef CONFIG_NO_HZ_FULL

extern void tick_nohz_init(void);

extern int tick_nohz_full_cpu(int cpu);

extern void tick_nohz_full_check(void);

extern void tick_nohz_full_kick(void);

extern void tick_nohz_full_kick_all(void);

extern void tick_nohz_task_switch(struct task_struct *tsk);

#else

static inline void tick_nohz_init(void) { }

static inline int tick_nohz_full_cpu(int cpu) { return 0; }

static inline void tick_nohz_full_check(void) { }

static inline void tick_nohz_full_kick(void) { }

static inline void tick_nohz_full_kick_all(void) { }

static inline void tick_nohz_task_switch(struct task_struct *tsk) { }

#endif

kernel/events/core.c

+16 −1
Original line number Diff line number Diff line
@@ -18,6 +18,7 @@ 
#include <linux/poll.h>

#include <linux/slab.h>

#include <linux/hash.h>

#include <linux/tick.h>

#include <linux/sysfs.h>

#include <linux/dcache.h>

#include <linux/percpu.h>
@@ -655,8 +656,12 @@ static void perf_pmu_rotate_start(struct pmu *pmu) 


	WARN_ON(!irqs_disabled());



	if (list_empty(&cpuctx->rotation_list))

	if (list_empty(&cpuctx->rotation_list)) {

		int was_empty = list_empty(head);

		list_add(&cpuctx->rotation_list, head);

		if (was_empty)

			tick_nohz_full_kick();

	}

}



static void get_ctx(struct perf_event_context *ctx)
@@ -2555,6 +2560,16 @@ static void perf_rotate_context(struct perf_cpu_context *cpuctx) 
		list_del_init(&cpuctx->rotation_list);

}



#ifdef CONFIG_NO_HZ_FULL

bool perf_event_can_stop_tick(void)

{

	if (list_empty(&__get_cpu_var(rotation_list)))

		return true;

	else

		return false;

}

#endif



void perf_event_task_tick(void)

{

	struct list_head *head = &__get_cpu_var(rotation_list);

kernel/posix-cpu-timers.c

+3 −3
Original line number Diff line number Diff line
@@ -673,12 +673,12 @@ static void posix_cpu_timer_kick_nohz(void) 
bool posix_cpu_timers_can_stop_tick(struct task_struct *tsk)

{

	if (!task_cputime_zero(&tsk->cputime_expires))

		return true;

		return false;



	if (tsk->signal->cputimer.running)

		return true;



		return false;



	return true;

}

#else

static inline void posix_cpu_timer_kick_nohz(void) { }