diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2011-10-18 22:03:48 +0200 |
|---|---|---|
| committer | Clark Williams <williams@redhat.com> | 2012-02-15 10:32:28 -0600 |
| commit | 01f9ceee421ef3838c3cf720f86c7473b59a860a (patch) | |
| tree | df875238cf4998873a36f3d4894739d31c62cdf1 /kernel/sched_rt.c | |
| parent | 9779d147045e8423a0b5dbee281ea4fdb8ffa7b5 (diff) | |
sched: Do not throttle due to PI boosting
When a runqueue has rt_runtime_us = 0 then the only way it can
accumulate rt_time is via PI boosting. Though 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.
[ tglx: Preliminary changelog ]
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'kernel/sched_rt.c')
| -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 40d97e1bf9d3..c108b9ce0799 100644 --- a/kernel/sched_rt.c +++ b/kernel/sched_rt.c @@ -659,8 +659,24 @@ 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; |