Commit ae99286b authored Nov 10, 2008 by Thomas Gleixner Committed by Thomas Gleixner Nov 10, 2008

nohz: disable tick_nohz_kick_tick() for now



Impact: nohz powersavings and wakeup regression

commit fb02fbc1 (NOHZ: restart tick
device from irq_enter()) causes a serious wakeup regression.

While the patch is correct it does not take into account that spurious
wakeups happen on x86. A fix for this issue is available, but we just
revert to the .27 behaviour and let long running softirqs screw
themself.

Disable it for now.

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

parent ee5f80a9

kernel/time/tick-sched.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -568,6 +568,9 @@ static void tick_nohz_switch_to_nohz(void)
		*/
		static void tick_nohz_kick_tick(int cpu)
		{
		#if 0
		/* Switch back to 2.6.27 behaviour */

		struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
		ktime_t delta, now;

		@@ -584,6 +587,7 @@ static void tick_nohz_kick_tick(int cpu)
		return;

		tick_nohz_restart(ts, now);
		#endif
		}

		#else