From 33b8a7206ba184af2174e92a84e58a9e2bcbf6e9 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Mon, 10 Nov 2008 13:20:23 +0100 Subject: [PATCH] nohz: disable tick_nohz_kick_tick() for now Impact: nohz powersavings and wakeup regression commit b2cc86192696a099aff50fee5f9f8709d5dccd91 (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 --- kernel/time/tick-sched.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 5bbb1044f8473..342fc9ccab46d 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -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 -- 2.39.5