Merge "sched: Add a check for cpu unbound deferrable timers" (048c7007) · Commits · e / devices / android_kernel_sony_msm8998

include/linux/timer.h

+3 −0

Original line number	Diff line number	Diff line
		@@ -173,6 +173,9 @@ extern int mod_timer_pending(struct timer_list *timer, unsigned long expires);
		extern int mod_timer_pinned(struct timer_list *timer, unsigned long expires);

		extern void set_timer_slack(struct timer_list *time, int slack_hz);
		#ifdef CONFIG_SMP
		extern bool check_pending_deferrable_timers(int cpu);
		#endif

		#define TIMER_NOT_PINNED 0
		#define TIMER_PINNED 1

kernel/time/tick-sched.c

+6 −0

Original line number	Diff line number	Diff line
		@@ -19,6 +19,7 @@
		#include <linux/percpu.h>
		#include <linux/profile.h>
		#include <linux/sched.h>
		#include <linux/timer.h>
		#include <linux/module.h>
		#include <linux/irq_work.h>
		#include <linux/posix-timers.h>
		@@ -809,6 +810,11 @@ static void __tick_nohz_idle_enter(struct tick_sched *ts)

		now = tick_nohz_start_idle(ts);

		#ifdef CONFIG_SMP
		if (check_pending_deferrable_timers(cpu))
		raise_softirq_irqoff(TIMER_SOFTIRQ);
		#endif

		if (can_stop_idle_tick(cpu, ts)) {
		int was_stopped = ts->tick_stopped;

kernel/time/timer.c

+31 −3

Original line number	Diff line number	Diff line
		@@ -102,6 +102,7 @@ static DEFINE_PER_CPU(struct tvec_base, tvec_bases);
		unsigned int sysctl_timer_migration = 1;

		struct tvec_base tvec_base_deferrable;
		static atomic_t deferrable_pending;

		void timers_update_migration(bool update_nohz)
		{
		@@ -150,10 +151,13 @@ static inline struct tvec_base get_target_base(struct tvec_base base,

		static inline void __run_deferrable_timers(void)
		{
		if (smp_processor_id() == tick_do_timer_cpu &&
		time_after_eq(jiffies, tvec_base_deferrable.timer_jiffies))
		if (time_after_eq(jiffies, tvec_base_deferrable.timer_jiffies)) {
		if ((atomic_cmpxchg(&deferrable_pending, 1, 0) &&
		tick_do_timer_cpu == TICK_DO_TIMER_NONE) \|\|
		tick_do_timer_cpu == smp_processor_id())
		__run_timers(&tvec_base_deferrable);
		}
		}

		static inline void init_timer_deferrable_global(void)
		{
		@@ -1428,6 +1432,30 @@ static u64 cmp_next_hrtimer_event(u64 basem, u64 expires)
		return DIV_ROUND_UP_ULL(nextevt, TICK_NSEC) * TICK_NSEC;
		}

		#ifdef CONFIG_SMP
		/*
		* check_pending_deferrable_timers - Check for unbound deferrable timer expiry.
		* @cpu - Current CPU
		*
		* The function checks whether any global deferrable pending timers
		* are exipired or not. This function does not check cpu bounded
		* diferrable pending timers expiry.
		*
		* The function returns true when a cpu unbounded deferrable timer is expired.
		*/
		bool check_pending_deferrable_timers(int cpu)
		{
		if (cpu == tick_do_timer_cpu \|\|
		tick_do_timer_cpu == TICK_DO_TIMER_NONE) {
		if (time_after_eq(jiffies, tvec_base_deferrable.timer_jiffies)
		&& !atomic_cmpxchg(&deferrable_pending, 0, 1)) {
		return true;
		}
		}
		return false;
		}
		#endif

		/**
		* get_next_timer_interrupt - return the time (clock mono) of the next timer
		* @basej: base time jiffies