On Fri, May 23, 2014 at 05:53:04PM +0200, Vincent Guittot wrote: > @@ -7282,6 +7289,12 @@ static inline int nohz_kick_needed(struct rq *rq) > > if (nr_busy > 1) > goto need_kick_unlock; > + > + if ((rq->cfs.h_nr_running >= 1) > + && ((rq->cpu_power * sd->imbalance_pct) < > + (rq->cpu_power_orig * 100))) > + goto need_kick_unlock; > + > } > > sd = rcu_dereference(per_cpu(sd_asym, cpu));
So what happens when a cpu is consistently low on power (say due to a pinned RT task) the balancer would quickly adjust the load level, but this would endlessly kick things into action, even though we're balanced just fine. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
