summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorVincent Guittot <vincent.guittot@linaro.org>2012-10-06 12:27:48 +0200
committerChander Kashyap <chander.kashyap@linaro.org>2013-03-14 18:44:23 +0530
commit9ebc7d164e1a3dc319aa9d761ed07fbe8d9b13c4 (patch)
tree4a6a42bc2ff09cf1b3685b1500649c946a3dff66
parent702a082a8a956d6b29d251967a06b58aee2fb053 (diff)
downloadkernel-9ebc7d164e1a3dc319aa9d761ed07fbe8d9b13c4.tar.gz
sched: pack the idle load balance
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 <vincent.guittot@linaro.org>
-rw-r--r--kernel/sched/fair.c18
1 files changed, 18 insertions, 0 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 150ebff048d..05e03f2daf3 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6049,7 +6049,25 @@ 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;
+ }
if (ilb < nr_cpu_ids && idle_cpu(ilb))
return ilb;