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authorMike Galbraith <efault@gmx.de>2011-04-29 08:36:50 +0200
committerIngo Molnar <mingo@elte.hu>2011-05-16 11:01:17 +0200
commit61eadef6a9bde9ea62fda724a9cb501ce9bc925a (patch)
tree52ffdd4251e921681f086ec6c4e14ad6e5f9472d /kernel/sched_rt.c
parent3e51e3edfd81bfd9853ad7de91167e4ce33d0fe7 (diff)
downloadop-kernel-dev-61eadef6a9bde9ea62fda724a9cb501ce9bc925a.zip
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sched, rt: Update rq clock when unthrottling of an otherwise idle CPU
If an RT task is awakened while it's rt_rq is throttled, the time between wakeup/enqueue and unthrottle/selection may be accounted as rt_time if the CPU is idle. Set rq->skip_clock_update negative upon throttle release to tell put_prev_task() that we need a clock update. Reported-by: Thomas Giesel <skoe@directbox.com> Signed-off-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1304059010.7472.1.camel@marge.simson.net Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/sched_rt.c')
-rw-r--r--kernel/sched_rt.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index 19ecb31..0943ed7 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -562,6 +562,13 @@ static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun)
if (rt_rq->rt_throttled && rt_rq->rt_time < runtime) {
rt_rq->rt_throttled = 0;
enqueue = 1;
+
+ /*
+ * Force a clock update if the CPU was idle,
+ * lest wakeup -> unthrottle time accumulate.
+ */
+ if (rt_rq->rt_nr_running && rq->curr == rq->idle)
+ rq->skip_clock_update = -1;
}
if (rt_rq->rt_time || rt_rq->rt_nr_running)
idle = 0;
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