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| author | Peter Zijlstra <peterz@infradead.org> | 2011-10-18 22:03:48 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2012-03-01 10:28:02 +0100 |
| commit | 7abc63b1bd412f7655b62ef3e35c3c11c5134636 (patch) | |
| tree | c2a18d2b57d71d124ddb280d396df94b7110448f | |
| parent | 42c62a589f1ccbf38a02cb732231f9c2fccc5ab0 (diff) | |
| download | linux-7abc63b1bd412f7655b62ef3e35c3c11c5134636.tar.gz linux-7abc63b1bd412f7655b62ef3e35c3c11c5134636.tar.bz2 linux-7abc63b1bd412f7655b62ef3e35c3c11c5134636.zip | |
sched/rt: Do not throttle when PI boosting
When a runqueue has rt_runtime_us = 0 then the only way it can
accumulate rt_time is via PI boosting. That causes the runqueue
to be throttled and replenishing does not change anything due to
rt_runtime_us = 0. So avoid that situation by clearing rt_time and
skip the throttling alltogether.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
[ Changelog ]
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/n/tip-7x70cypsotjb4jvcor3edctk@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
| -rw-r--r-- | kernel/sched/rt.c | 20 |
1 files changed, 18 insertions, 2 deletions
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index 6d1eb0be1870..7f7e7cdcb472 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -857,8 +857,24 @@ static int sched_rt_runtime_exceeded(struct rt_rq *rt_rq) return 0; if (rt_rq->rt_time > runtime) { - rt_rq->rt_throttled = 1; - printk_once(KERN_WARNING "sched: RT throttling activated\n"); + struct rt_bandwidth *rt_b = sched_rt_bandwidth(rt_rq); + + /* + * Don't actually throttle groups that have no runtime assigned + * but accrue some time due to boosting. + */ + if (likely(rt_b->rt_runtime)) { + rt_rq->rt_throttled = 1; + printk_once(KERN_WARNING "sched: RT throttling activated\n"); + } else { + /* + * In case we did anyway, make it go away, + * replenishment is a joke, since it will replenish us + * with exactly 0 ns. + */ + rt_rq->rt_time = 0; + } + if (rt_rq_throttled(rt_rq)) { sched_rt_rq_dequeue(rt_rq); return 1; |