Merge "timer: Don't wait for running timers when migrating during isolation" (17878012) · Commits · e / devices / android_kernel_sony_msm8998

kernel/time/hrtimer.c

+7 −0

Original line number	Diff line number	Diff line
		@@ -49,6 +49,7 @@
		#include <linux/sched/deadline.h>
		#include <linux/timer.h>
		#include <linux/freezer.h>
		#include <linux/delay.h>

		#include <asm/uaccess.h>

		@@ -1648,6 +1649,12 @@ static void migrate_hrtimer_list(struct hrtimer_cpu_base *old_base,
		raw_spin_unlock(&old_base->lock);
		raw_spin_unlock(&new_base->lock);
		cpu_relax();
		/*
		* cpu_relax may just be a barrier. Grant the
		* run_hrtimer_list code some time to obtain the
		* spinlock.
		*/
		udelay(2);
		raw_spin_lock(&new_base->lock);
		raw_spin_lock_nested(&old_base->lock,
		SINGLE_DEPTH_NESTING);

kernel/time/timer.c

+10 −14

Original line number	Diff line number	Diff line
		@@ -1640,7 +1640,7 @@ static void migrate_timer_list(struct tvec_base *new_base,
		}
		}

		static void __migrate_timers(int cpu, bool wait, bool remove_pinned)
		static void __migrate_timers(int cpu, bool remove_pinned)
		{
		struct tvec_base *old_base;
		struct tvec_base *new_base;
		@@ -1656,18 +1656,14 @@ static void __migrate_timers(int cpu, bool wait, bool remove_pinned)
		spin_lock_irqsave(&new_base->lock, flags);
		spin_lock_nested(&old_base->lock, SINGLE_DEPTH_NESTING);

		if (wait) {
		/* Ensure timers are done running before continuing */
		while (old_base->running_timer) {
		spin_unlock(&old_base->lock);
		spin_unlock_irqrestore(&new_base->lock, flags);
		cpu_relax();
		spin_lock_irqsave(&new_base->lock, flags);
		spin_lock_nested(&old_base->lock, SINGLE_DEPTH_NESTING);
		}
		} else {
		/*
		* If we're in the hotplug path, kill the system if there's a running
		* timer. It's ok to have a running timer in the isolation case - the
		* currently running or just expired timers are off of the timer wheel
		* and so everything else can be migrated off.
		*/
		if (!cpu_online(cpu))
		BUG_ON(old_base->running_timer);
		}

		for (i = 0; i < TVR_SIZE; i++)
		migrate_timer_list(new_base, old_base->tv1.vec + i,
		@@ -1692,12 +1688,12 @@ static void __migrate_timers(int cpu, bool wait, bool remove_pinned)
		static void migrate_timers(int cpu)
		{
		BUG_ON(cpu_online(cpu));
		__migrate_timers(cpu, false, true);
		__migrate_timers(cpu, true);
		}

		void timer_quiesce_cpu(void *cpup)
		{
		__migrate_timers((int )cpup, true, false);
		__migrate_timers((int )cpup, false);
		}

		static int timer_cpu_notify(struct notifier_block *self,