timers: Reuse next expiry cache after nohz exit (90d52f65) · Commits · 戴 / test

Now that the next expiry it tracked unconditionally when a timer is added, this information can be reused on a tick firing after exiting nohz. Signed-off-by:

Frederic Weisbecker <frederic@kernel.org> Signed-off-by:

Thomas Gleixner <tglx@linutronix.de> Tested-by:

Juri Lelli <juri.lelli@redhat.com> Link: https://lkml.kernel.org/r/20200717140551.29076-9-frederic@kernel.org

kernel/time/timer.c

+2 −4

Original line number	Diff line number	Diff line
		@@ -1706,13 +1706,11 @@ static int collect_expired_timers(struct timer_base *base,
		* the next expiring timer.
		*/
		if ((long)(now - base->clk) > 2) {
		unsigned long next = __next_timer_interrupt(base);

		/*
		* If the next timer is ahead of time forward to current
		* jiffies, otherwise forward to the next expiry time:
		*/
		if (time_after(next, now)) {
		if (time_after(base->next_expiry, now)) {
		/*
		* The call site will increment base->clk and then
		* terminate the expiry loop immediately.
		@@ -1720,7 +1718,7 @@ static int collect_expired_timers(struct timer_base *base,
		base->clk = now;
		return 0;
		}
		base->clk = next;
		base->clk = base->next_expiry;
		}
		return __collect_expired_timers(base, heads);
		}

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