Commit e23604ed authored by Linus Torvalds's avatar Linus Torvalds
Browse files

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

Pull NOHZ updates from Ingo Molnar:
 "NOHZ enhancements, by Frederic Weisbecker, which reorganizes/refactors
  the NOHZ 'can the tick be stopped?' infrastructure and related code to
  be data driven, and harmonizes the naming and handling of all the
  various properties"

[ This makes the ugly "fetch_or()" macro that the scheduler used
  internally a new generic helper, and does a bad job at it.

  I'm pulling it, but I've asked Ingo and Frederic to get this
  fixed up ]

* 'timers-nohz-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched-clock: Migrate to use new tick dependency mask model
  posix-cpu-timers: Migrate to use new tick dependency mask model
  sched: Migrate sched to use new tick dependency mask model
  sched: Account rr tasks
  perf: Migrate perf to use new tick dependency mask model
  nohz: Use enum code for tick stop failure tracing message
  nohz: New tick dependency mask
  nohz: Implement wide kick on top of irq work
  atomic: Export fetch_or()
parents d4e79615 1f251846

include/linux/atomic.h

+21 −0
Original line number Diff line number Diff line
@@ -548,6 +548,27 @@ static inline int atomic_dec_if_positive(atomic_t *v) 
}

#endif



/**

 * fetch_or - perform *ptr |= mask and return old value of *ptr

 * @ptr: pointer to value

 * @mask: mask to OR on the value

 *

 * cmpxchg based fetch_or, macro so it works for different integer types

 */

#ifndef fetch_or

#define fetch_or(ptr, mask)						\

({	typeof(*(ptr)) __old, __val = *(ptr);				\

	for (;;) {							\

		__old = cmpxchg((ptr), __val, __val | (mask));		\

		if (__old == __val)					\

			break;						\

		__val = __old;						\

	}								\

	__old;								\

})

#endif





#ifdef CONFIG_GENERIC_ATOMIC64

#include <asm-generic/atomic64.h>

#endif

include/linux/perf_event.h

+0 −6
Original line number Diff line number Diff line
@@ -1110,12 +1110,6 @@ static inline void perf_event_task_tick(void) { } 
static inline int perf_event_release_kernel(struct perf_event *event)	{ return 0; }

#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



#if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_CPU_SUP_INTEL)

extern void perf_restore_debug_store(void);

#else

include/linux/posix-timers.h

+0 −3
Original line number Diff line number Diff line
@@ -128,9 +128,6 @@ void posix_cpu_timer_schedule(struct k_itimer *timer); 
void run_posix_cpu_timers(struct task_struct *task);

void posix_cpu_timers_exit(struct task_struct *task);

void posix_cpu_timers_exit_group(struct task_struct *task);



bool posix_cpu_timers_can_stop_tick(struct task_struct *tsk);



void set_process_cpu_timer(struct task_struct *task, unsigned int clock_idx,

			   cputime_t *newval, cputime_t *oldval);

include/linux/sched.h

+8 −3
Original line number Diff line number Diff line
@@ -717,6 +717,10 @@ struct signal_struct { 
	/* Earliest-expiration cache. */

	struct task_cputime cputime_expires;



#ifdef CONFIG_NO_HZ_FULL

	unsigned long tick_dep_mask;

#endif



	struct list_head cpu_timers[3];



	struct pid *tty_old_pgrp;
@@ -1542,6 +1546,10 @@ struct task_struct { 
		VTIME_SYS,

	} vtime_snap_whence;

#endif



#ifdef CONFIG_NO_HZ_FULL

	unsigned long tick_dep_mask;

#endif

	unsigned long nvcsw, nivcsw; /* context switch counts */

	u64 start_time;		/* monotonic time in nsec */

	u64 real_start_time;	/* boot based time in nsec */
@@ -2356,10 +2364,7 @@ static inline void wake_up_nohz_cpu(int cpu) { } 
#endif



#ifdef CONFIG_NO_HZ_FULL

extern bool sched_can_stop_tick(void);

extern u64 scheduler_tick_max_deferment(void);

#else

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

#endif



#ifdef CONFIG_SCHED_AUTOGROUP

include/linux/tick.h

+93 −4
Original line number Diff line number Diff line
@@ -97,6 +97,19 @@ static inline void tick_broadcast_exit(void) 
	tick_broadcast_oneshot_control(TICK_BROADCAST_EXIT);

}



enum tick_dep_bits {

	TICK_DEP_BIT_POSIX_TIMER	= 0,

	TICK_DEP_BIT_PERF_EVENTS	= 1,

	TICK_DEP_BIT_SCHED		= 2,

	TICK_DEP_BIT_CLOCK_UNSTABLE	= 3

};



#define TICK_DEP_MASK_NONE		0

#define TICK_DEP_MASK_POSIX_TIMER	(1 << TICK_DEP_BIT_POSIX_TIMER)

#define TICK_DEP_MASK_PERF_EVENTS	(1 << TICK_DEP_BIT_PERF_EVENTS)

#define TICK_DEP_MASK_SCHED		(1 << TICK_DEP_BIT_SCHED)

#define TICK_DEP_MASK_CLOCK_UNSTABLE	(1 << TICK_DEP_BIT_CLOCK_UNSTABLE)



#ifdef CONFIG_NO_HZ_COMMON

extern int tick_nohz_enabled;

extern int tick_nohz_tick_stopped(void);
@@ -154,9 +167,73 @@ static inline int housekeeping_any_cpu(void) 
	return cpumask_any_and(housekeeping_mask, cpu_online_mask);

}



extern void tick_nohz_full_kick(void);

extern void tick_nohz_dep_set(enum tick_dep_bits bit);

extern void tick_nohz_dep_clear(enum tick_dep_bits bit);

extern void tick_nohz_dep_set_cpu(int cpu, enum tick_dep_bits bit);

extern void tick_nohz_dep_clear_cpu(int cpu, enum tick_dep_bits bit);

extern void tick_nohz_dep_set_task(struct task_struct *tsk,

				   enum tick_dep_bits bit);

extern void tick_nohz_dep_clear_task(struct task_struct *tsk,

				     enum tick_dep_bits bit);

extern void tick_nohz_dep_set_signal(struct signal_struct *signal,

				     enum tick_dep_bits bit);

extern void tick_nohz_dep_clear_signal(struct signal_struct *signal,

				       enum tick_dep_bits bit);



/*

 * The below are tick_nohz_[set,clear]_dep() wrappers that optimize off-cases

 * on top of static keys.

 */

static inline void tick_dep_set(enum tick_dep_bits bit)

{

	if (tick_nohz_full_enabled())

		tick_nohz_dep_set(bit);

}



static inline void tick_dep_clear(enum tick_dep_bits bit)

{

	if (tick_nohz_full_enabled())

		tick_nohz_dep_clear(bit);

}



static inline void tick_dep_set_cpu(int cpu, enum tick_dep_bits bit)

{

	if (tick_nohz_full_cpu(cpu))

		tick_nohz_dep_set_cpu(cpu, bit);

}



static inline void tick_dep_clear_cpu(int cpu, enum tick_dep_bits bit)

{

	if (tick_nohz_full_cpu(cpu))

		tick_nohz_dep_clear_cpu(cpu, bit);

}



static inline void tick_dep_set_task(struct task_struct *tsk,

				     enum tick_dep_bits bit)

{

	if (tick_nohz_full_enabled())

		tick_nohz_dep_set_task(tsk, bit);

}

static inline void tick_dep_clear_task(struct task_struct *tsk,

				       enum tick_dep_bits bit)

{

	if (tick_nohz_full_enabled())

		tick_nohz_dep_clear_task(tsk, bit);

}

static inline void tick_dep_set_signal(struct signal_struct *signal,

				       enum tick_dep_bits bit)

{

	if (tick_nohz_full_enabled())

		tick_nohz_dep_set_signal(signal, bit);

}

static inline void tick_dep_clear_signal(struct signal_struct *signal,

					 enum tick_dep_bits bit)

{

	if (tick_nohz_full_enabled())

		tick_nohz_dep_clear_signal(signal, bit);

}



extern void tick_nohz_full_kick_cpu(int cpu);

extern void tick_nohz_full_kick_all(void);

extern void __tick_nohz_task_switch(void);

#else

static inline int housekeeping_any_cpu(void)
@@ -166,9 +243,21 @@ static inline int housekeeping_any_cpu(void) 
static inline bool tick_nohz_full_enabled(void) { return false; }

static inline bool tick_nohz_full_cpu(int cpu) { return false; }

static inline void tick_nohz_full_add_cpus_to(struct cpumask *mask) { }



static inline void tick_dep_set(enum tick_dep_bits bit) { }

static inline void tick_dep_clear(enum tick_dep_bits bit) { }

static inline void tick_dep_set_cpu(int cpu, enum tick_dep_bits bit) { }

static inline void tick_dep_clear_cpu(int cpu, enum tick_dep_bits bit) { }

static inline void tick_dep_set_task(struct task_struct *tsk,

				     enum tick_dep_bits bit) { }

static inline void tick_dep_clear_task(struct task_struct *tsk,

				       enum tick_dep_bits bit) { }

static inline void tick_dep_set_signal(struct signal_struct *signal,

				       enum tick_dep_bits bit) { }

static inline void tick_dep_clear_signal(struct signal_struct *signal,

					 enum tick_dep_bits bit) { }



static inline void tick_nohz_full_kick_cpu(int cpu) { }

static inline void tick_nohz_full_kick(void) { }

static inline void tick_nohz_full_kick_all(void) { }

static inline void __tick_nohz_task_switch(void) { }

#endif

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