Subject: sched, fair: Fix group power_orig computation
From: Peter Zijlstra <pet...@infradead.org>
Date: Wed Aug 28 11:44:39 CEST 2013
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 <mi...@neuling.org>
Signed-off-by: Peter Zijlstra <pet...@infradead.org>
---
kernel/sched/fair.c | 40 ++++++++++++++++++++++++++--------------
1 file changed, 26 insertions(+), 14 deletions(-)
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -4448,7 +4448,7 @@ void update_group_power(struct sched_dom
{
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);
@@ -4460,7 +4460,7 @@ void update_group_power(struct sched_dom
return;
}
- power = 0;
+ power_orig = power = 0;
if (child->flags & SD_OVERLAP) {
/*
@@ -4468,8 +4468,12 @@ void update_group_power(struct sched_dom
* 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
@@ -4478,12 +4482,14 @@ void update_group_power(struct sched_dom
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;
}
/*
--
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