Commit 03e6bdc5 authored Apr 15, 2014 by Viresh Kumar Committed by Thomas Gleixner Apr 15, 2014

tick-sched: Don't call update_wall_time() when delta is lesser than tick_period



In tick_do_update_jiffies64() we are processing ticks only if delta is
greater than tick_period. This is what we are supposed to do here and
it broke a bit with this patch:

commit 47a1b796 (tick/timekeeping: Call update_wall_time outside the
jiffies lock)

With above patch, we might end up calling update_wall_time() even if
delta is found to be smaller that tick_period. Fix this by returning
when the delta is less than tick period.

[ tglx: Made it a 3 liner and massaged changelog ]

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: linaro-kernel@lists.linaro.org
Cc: fweisbec@gmail.com
Cc: Arvind.Chauhan@arm.com
Cc: linaro-networking@linaro.org
Cc: John Stultz <john.stultz@linaro.org>
Cc: <stable@vger.kernel.org> # v3.14+
Link: http://lkml.kernel.org/r/80afb18a494b0bd9710975bcc4de134ae323c74f.1397537987.git.viresh.kumar@linaro.org


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

parent 521c4299

kernel/time/tick-sched.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -84,6 +84,9 @@ static void tick_do_update_jiffies64(ktime_t now)

		/* Keep the tick_next_period variable up to date */
		tick_next_period = ktime_add(last_jiffies_update, tick_period);
		} else {
		write_sequnlock(&jiffies_lock);
		return;
		}
		write_sequnlock(&jiffies_lock);
		update_wall_time();

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