X-Git-Url: http://git.agner.ch/gitweb/?a=blobdiff_plain;f=kernel%2Fsched%2Ffair.c;h=fd773ade1a3141cd4b152cb8fce905866a7c223a;hb=59fb2f0e9e30ad99a8bab0ff1efaf8f4a3b7105f;hp=e8b652ebe027c481e87122f629a300058cf82679;hpb=b8aba7611b9a5a1f67f081be84270c67baf4d2c3;p=linux-drm-fsl-dcu.git

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index e8b652ebe027..fd773ade1a31 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -5379,10 +5379,31 @@ void update_group_power(struct sched_domain *sd, int cpu)
 		 */
 
 		for_each_cpu(cpu, sched_group_cpus(sdg)) {
-			struct sched_group *sg = cpu_rq(cpu)->sd->groups;
+			struct sched_group_power *sgp;
+			struct rq *rq = cpu_rq(cpu);
 
-			power_orig += sg->sgp->power_orig;
-			power += sg->sgp->power;
+			/*
+			 * build_sched_domains() -> init_sched_groups_power()
+			 * gets here before we've attached the domains to the
+			 * runqueues.
+			 *
+			 * Use power_of(), which is set irrespective of domains
+			 * in update_cpu_power().
+			 *
+			 * This avoids power/power_orig from being 0 and
+			 * causing divide-by-zero issues on boot.
+			 *
+			 * Runtime updates will correct power_orig.
+			 */
+			if (unlikely(!rq->sd)) {
+				power_orig += power_of(cpu);
+				power += power_of(cpu);
+				continue;
+			}
+
+			sgp = rq->sd->groups->sgp;
+			power_orig += sgp->power_orig;
+			power += sgp->power;
 		}
 	} else  {
 		/*