Merge "Revert "time: Run deferrable timers on other CPUs when tick_do_timer_cpu is busy"" (5178e189) · Commits · e / devices / android_kernel_fairphone_FP3

include/linux/interrupt.h

+0 −8

Original line number	Diff line number	Diff line
		@@ -14,7 +14,6 @@
		#include <linux/hrtimer.h>
		#include <linux/kref.h>
		#include <linux/workqueue.h>
		#include <linux/sched.h>

		#include <linux/atomic.h>
		#include <asm/ptrace.h>
		@@ -499,13 +498,6 @@ static inline struct task_struct *this_cpu_ksoftirqd(void)
		return this_cpu_read(ksoftirqd);
		}

		static inline bool ksoftirqd_running_on(int cpu)
		{
		struct task_struct *tsk = per_cpu(ksoftirqd, cpu);

		return tsk && (tsk->state == TASK_RUNNING);
		}

		/* Tasklets --- multithreaded analogue of BHs.

		Main feature differing them of generic softirqs: tasklet

kernel/time/timer.c

+4 −24

Original line number	Diff line number	Diff line
		@@ -208,6 +208,7 @@ struct timer_base {

		static DEFINE_PER_CPU(struct timer_base, timer_bases[NR_BASES]);
		struct timer_base timer_base_deferrable;
		static atomic_t deferrable_pending;

		#if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
		unsigned int sysctl_timer_migration = 1;
		@@ -1488,8 +1489,6 @@ static u64 cmp_next_hrtimer_event(u64 basem, u64 expires)


		#ifdef CONFIG_SMP
		static atomic_t deferrable_pending;

		/*
		* check_pending_deferrable_timers - Check for unbound deferrable timer expiry
		* @cpu - Current CPU
		@@ -1670,27 +1669,6 @@ static inline void __run_timers(struct timer_base *base)
		spin_unlock_irq(&base->lock);
		}

		#ifdef CONFIG_SMP
		static inline bool should_this_cpu_run_deferrable_timers(void)
		{
		int tick_cpu = READ_ONCE(tick_do_timer_cpu);

		if (atomic_cmpxchg(&deferrable_pending, 1, 0) &&
		tick_cpu == TICK_DO_TIMER_NONE)
		return true;

		if (tick_cpu == smp_processor_id())
		return true;

		return (tick_cpu >= 0 && ksoftirqd_running_on(tick_cpu));
		}
		#else
		static inline bool should_this_cpu_run_deferrable_timers(void)
		{
		return true;
		}
		#endif

		/*
		* This function runs timers and the timer-tq in bottom half context.
		*/
		@@ -1715,7 +1693,9 @@ static __latent_entropy void run_timer_softirq(struct softirq_action *h)
		if (IS_ENABLED(CONFIG_NO_HZ_COMMON))
		__run_timers(this_cpu_ptr(&timer_bases[BASE_DEF]));

		if (should_this_cpu_run_deferrable_timers())
		if ((atomic_cmpxchg(&deferrable_pending, 1, 0) &&
		tick_do_timer_cpu == TICK_DO_TIMER_NONE) \|\|
		tick_do_timer_cpu == smp_processor_id())
		__run_timers(&timer_base_deferrable);
		}