On Thu, Apr 24, 2014 at 11:30:59AM +0100, Morten Rasmussen wrote: > On Thu, Apr 24, 2014 at 02:30:35AM +0100, Jason Low wrote: > > @@ -6704,7 +6703,12 @@ static int idle_balance(struct rq *this_rq) > > interval = msecs_to_jiffies(sd->balance_interval); > > if (time_after(next_balance, sd->last_balance + interval)) > > next_balance = sd->last_balance + interval; > > - if (pulled_task) > > + > > + /* > > + * Stop searching for tasks to pull if there are > > + * now runnable tasks on this rq. > > + */ > > + if (pulled_task || this_rq->nr_running > 0) > > Should this be cfs tasks instead? > > + if (pulled_task || this_rq->cfs.h_nr_running > 0) > > 3.15-rc2 commit 35805ff8f4fc535ac85330170d3c56829c87c677 seems to > indicate that using rq->nr_running may lead to trouble. > > The other two patches look good to me.
No, this really wants to be nr_running, we want to bail the idle balancer when there's anything runnable present. Note how out: is very careful to return -1 (which results in RETRY_TASK) when rq->nr_running != rq->cfs.h_nr_running. That same out: test also makes problem that commit fixes impossible again. -- 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/
