On Fri, 2013-03-22 at 13:25 +0100, 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 | 18 ++++++++++++++++++ > 1 file changed, 18 insertions(+) > > diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c > index b636199..52a7736 100644 > --- a/kernel/sched/fair.c > +++ b/kernel/sched/fair.c > @@ -5455,7 +5455,25 @@ 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; > + }
/me hands you a fresh bucket of curlies, no reason to skimp on them. But ha! here's your NO_HZ link.. but does the above DTRT and ensure that the ILB is a little core when possible? -- 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/
