From 56c7426b3951e4f35a71d695f1c982989399d6fd Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Mon, 1 Sep 2008 16:44:23 +0200 Subject: [PATCH] sched_clock: fix NOHZ interaction If HLT stops the TSC, we'll fail to account idle time, thereby inflating the actual process times. Fix this by re-calibrating the clock against GTOD when leaving nohz mode. Signed-off-by: Peter Zijlstra Tested-by: Avi Kivity Signed-off-by: Ingo Molnar --- kernel/time/tick-sched.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 7a46bde..a87b046 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -162,6 +162,8 @@ void tick_nohz_stop_idle(int cpu) ts->idle_lastupdate = now; ts->idle_sleeptime = ktime_add(ts->idle_sleeptime, delta); ts->idle_active = 0; + + sched_clock_idle_wakeup_event(0); } } @@ -177,6 +179,7 @@ static ktime_t tick_nohz_start_idle(struct tick_sched *ts) } ts->idle_entrytime = now; ts->idle_active = 1; + sched_clock_idle_sleep_event(); return now; } -- 1.8.2.3