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authorPeter Zijlstra <a.p.zijlstra@chello.nl>2008-09-01 16:44:23 +0200
committerIngo Molnar <mingo@elte.hu>2008-09-05 18:14:08 +0200
commit56c7426b3951e4f35a71d695f1c982989399d6fd (patch)
tree26001a24308baceab1ff36eb8ab1ed43fb831a4f
parentb380b0d4f7dffcc235c0facefa537d4655619101 (diff)
downloadblackbird-op-linux-56c7426b3951e4f35a71d695f1c982989399d6fd.tar.gz
blackbird-op-linux-56c7426b3951e4f35a71d695f1c982989399d6fd.zip
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 <a.p.zijlstra@chello.nl> Tested-by: Avi Kivity <avi@qumranet.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
-rw-r--r--kernel/time/tick-sched.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 7a46bde78c66..a87b0468568b 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;
}
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