On Thu, Apr 25, 2013 at 07:23:20PM +0200, Vincent Guittot wrote: > Look for an idle CPU close to the pack buddy CPU whenever possible. > The goal is to prevent the wake up of a CPU which doesn't share the power > domain of the pack buddy CPU. > > Signed-off-by: Vincent Guittot <[email protected]> > Reviewed-by: Morten Rasmussen <[email protected]> > --- > kernel/sched/fair.c | 19 +++++++++++++++++++ > 1 file changed, 19 insertions(+) > > diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c > index 6adc57c..a985c98 100644 > --- a/kernel/sched/fair.c > +++ b/kernel/sched/fair.c > @@ -5469,7 +5469,26 @@ static struct { > > static inline int find_new_ilb(int call_cpu) > { > + struct sched_domain *sd; > int ilb = cpumask_first(nohz.idle_cpus_mask); > + int buddy = per_cpu(sd_pack_buddy, call_cpu); > + > + /* > + * If we have a pack buddy CPU, we try to run load balance on a CPU > + * that is close to the buddy. > + */ > + if (buddy != -1) { > + for_each_domain(buddy, sd) { > + if (sd->flags & SD_SHARE_CPUPOWER) > + continue; > + > + ilb = cpumask_first_and(sched_domain_span(sd), > + nohz.idle_cpus_mask); > + > + if (ilb < nr_cpu_ids) > + break; > + } > + } > > if (ilb < nr_cpu_ids && idle_cpu(ilb)) > return ilb;
Ha! and here you hope people won't put multiple big-little clusters in a single machine? :-) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
