Messages in this thread | | | Date | Thu, 10 Jul 2014 13:31:20 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH v3 08/12] sched: move cfs task on a CPU with higher capacity |
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On Mon, Jun 30, 2014 at 06:05:39PM +0200, Vincent Guittot wrote:
You 'forgot' to update the comment that goes with nohz_kick_needed().
> @@ -7233,9 +7253,10 @@ static inline int nohz_kick_needed(struct rq *rq) > struct sched_domain *sd; > struct sched_group_capacity *sgc; > int nr_busy, cpu = rq->cpu; > + bool kick = false; > > if (unlikely(rq->idle_balance)) > + return false; > > /* > * We may be recently in ticked or tickless idle mode. At the first > @@ -7249,38 +7270,41 @@ static inline int nohz_kick_needed(struct rq *rq) > * balancing. > */ > if (likely(!atomic_read(&nohz.nr_cpus))) > + return false; > > if (time_before(now, nohz.next_balance)) > + return false; > > if (rq->nr_running >= 2) > + return true; > > rcu_read_lock(); > sd = rcu_dereference(per_cpu(sd_busy, cpu)); > if (sd) { > sgc = sd->groups->sgc; > nr_busy = atomic_read(&sgc->nr_busy_cpus); > > + if (nr_busy > 1) { > + kick = true; > + goto unlock; > + } > + > + if ((rq->cfs.h_nr_running >= 1) > + && ((rq->cpu_capacity * sd->imbalance_pct) < > + (rq->cpu_capacity_orig * 100))) { > + kick = true; > + goto unlock; > + }
Again, why only for shared caches?
> } > > sd = rcu_dereference(per_cpu(sd_asym, cpu)); > if (sd && (cpumask_first_and(nohz.idle_cpus_mask, > sched_domain_span(sd)) < cpu)) > + kick = true; > > +unlock: > rcu_read_unlock(); > + return kick; > }
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