Messages in this thread | | | Subject | Re: [patch 08/18] sched: add support for throttling group entities | From | Peter Zijlstra <> | Date | Mon, 08 Aug 2011 18:00:28 +0200 |
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On Mon, 2011-08-08 at 23:46 +0800, Lin Ming wrote: > On Fri, Jul 22, 2011 at 12:43 AM, Paul Turner <pjt@google.com> wrote: > > > +static __used void throttle_cfs_rq(struct cfs_rq *cfs_rq) > > +{ > > + struct rq *rq = rq_of(cfs_rq); > > + struct cfs_bandwidth *cfs_b = tg_cfs_bandwidth(cfs_rq->tg); > > + struct sched_entity *se; > > + long task_delta, dequeue = 1; > > + > > + se = cfs_rq->tg->se[cpu_of(rq_of(cfs_rq))]; > > + > > + /* account load preceding throttle */ > > + update_cfs_load(cfs_rq, 0); > > + > > + task_delta = cfs_rq->h_nr_running; > > + for_each_sched_entity(se) { > > + struct cfs_rq *qcfs_rq = cfs_rq_of(se); > > + /* throttled entity or throttle-on-deactivate */ > > + if (!se->on_rq) > > + break; > > Does it mean it's possible that child se is unthrottled but parent se > is throttled?
Yep..
> I thought if parent group was throttled then its children should be > throttled too. > I may misunderstood the code, please correct me then.
That would be costly, as throttling a parent would require throttling all its children (of which there can be arbitrary many).
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