Messages in this thread | | | Date | Tue, 19 Aug 2008 11:33:49 -0700 | From | Max Krasnyansky <> | Subject | Re: [PATCH 2/6] sched: rt-bandwidth accounting fix |
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Peter Zijlstra wrote: > It fixes an accounting bug where we would continue accumulating runtime > even though the bandwidth control is disabled. This would lead to very long > throttle periods once bandwidth control gets turned on again. > > Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> > --- > kernel/sched_rt.c | 11 +++++------ > 1 file changed, 5 insertions(+), 6 deletions(-) > > Index: linux-2.6/kernel/sched_rt.c > =================================================================== > --- linux-2.6.orig/kernel/sched_rt.c > +++ linux-2.6/kernel/sched_rt.c > @@ -438,9 +438,6 @@ static int sched_rt_runtime_exceeded(str > { > u64 runtime = sched_rt_runtime(rt_rq); > > - if (runtime == RUNTIME_INF) > - return 0; > - > if (rt_rq->rt_throttled) > return rt_rq_throttled(rt_rq); > > @@ -491,9 +488,11 @@ static void update_curr_rt(struct rq *rq > rt_rq = rt_rq_of_se(rt_se); > > spin_lock(&rt_rq->rt_runtime_lock); > - rt_rq->rt_time += delta_exec; > - if (sched_rt_runtime_exceeded(rt_rq)) > - resched_task(curr); > + if (sched_rt_runtime(rt_rq) != RUNTIME_INF) { > + rt_rq->rt_time += delta_exec; > + if (sched_rt_runtime_exceeded(rt_rq)) > + resched_task(curr); > + } > spin_unlock(&rt_rq->rt_runtime_lock); > } > }
This will make 'disabled' case more expensive, will it not ? I mean now we'll have to run balance_runtime() even if throttling is disabled.
Do you guys mind if I make this stuff configurable ? ie Just like CONFIG_RT_GROUP_SCHED we could add CONFIG_RT_BANDWIDTH_THROTTLE.
Max
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