sched/fair: Fix group power_orig computation

When looking at the code I noticed we don't actually compute
sgp->power_orig correctly for groups, fix that.

Currently the only consumer of that value is fix_small_capacity()
which is only used on POWER7+ and that code excludes this case by
being limited to SD_SHARE_CPUPOWER which is only ever set on the SMT
domain which must be the lowest domain and this has singleton groups.

So nothing should be affected by this change.

Cc: Michael Neuling <mikey@neuling.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-db2pe0vxwunv37plc7onnugj@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index f9f4385..baba313 100644 (file)
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -4450,7 +4450,7 @@ void update_group_power(struct sched_domain *sd, int cpu)
 {
        struct sched_domain *child = sd->child;
        struct sched_group *group, *sdg = sd->groups;
-       unsigned long power;
+       unsigned long power, power_orig;
        unsigned long interval;
 
        interval = msecs_to_jiffies(sd->balance_interval);
@@ -4462,7 +4462,7 @@ void update_group_power(struct sched_domain *sd, int cpu)
                return;
        }
 
-       power = 0;
+       power_orig = power = 0;
 
        if (child->flags & SD_OVERLAP) {
                /*
@@ -4470,8 +4470,12 @@ void update_group_power(struct sched_domain *sd, int cpu)
                 * span the current group.
                 */
 
-               for_each_cpu(cpu, sched_group_cpus(sdg))
-                       power += power_of(cpu);
+               for_each_cpu(cpu, sched_group_cpus(sdg)) {
+                       struct sched_group *sg = cpu_rq(cpu)->sd->groups;
+
+                       power_orig += sg->sgp->power_orig;
+                       power += sg->sgp->power;
+               }
        } else  {
                /*
                 * !SD_OVERLAP domains can assume that child groups
@@ -4480,12 +4484,14 @@ void update_group_power(struct sched_domain *sd, int cpu)
 
                group = child->groups;
                do {
+                       power_orig += group->sgp->power_orig;
                        power += group->sgp->power;
                        group = group->next;
                } while (group != child->groups);
        }
 
-       sdg->sgp->power_orig = sdg->sgp->power = power;
+       sdg->sgp->power_orig = power_orig;
+       sdg->sgp->power = power;
 }
 
 /*