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authorPeter Zijlstra <a.p.zijlstra@chello.nl>2009-12-03 18:00:07 +0100
committerIngo Molnar <mingo@elte.hu>2009-12-09 10:03:09 +0100
commitcd8ad40de36c2fe75f3b731bd70198b385895246 (patch)
treec1e6d5c8dddfa0d9ad643a1df8e92f26700e3143 /kernel/sched.c
parentsched: Remove unnecessary RCU exclusion (diff)
downloadlinux-cd8ad40de36c2fe75f3b731bd70198b385895246.tar.xz
linux-cd8ad40de36c2fe75f3b731bd70198b385895246.zip
sched: cgroup: Implement different treatment for idle shares
When setting the weight for a per-cpu task-group, we have to put in a phantom weight when there is no work on that cpu, otherwise we'll not service that cpu when new work gets placed there until we again update the per-cpu weights. We used to add these phantom weights to the total, so that the idle per-cpu shares don't get inflated, this however causes the non-idle parts to get deflated, causing unexpected weight distibutions. Reverse this, so that the non-idle shares are correct but the idle shares are inflated. Reported-by: Yasunori Goto <y-goto@jp.fujitsu.com> Tested-by: Yasunori Goto <y-goto@jp.fujitsu.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1257934048.23203.76.camel@twins> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/sched.c')
-rw-r--r--kernel/sched.c8
1 files changed, 6 insertions, 2 deletions
diff --git a/kernel/sched.c b/kernel/sched.c
index 0170735bdafc..71eb0622f548 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -1614,7 +1614,7 @@ static void update_group_shares_cpu(struct task_group *tg, int cpu,
*/
static int tg_shares_up(struct task_group *tg, void *data)
{
- unsigned long weight, rq_weight = 0, shares = 0;
+ unsigned long weight, rq_weight = 0, sum_weight = 0, shares = 0;
unsigned long *usd_rq_weight;
struct sched_domain *sd = data;
unsigned long flags;
@@ -1630,6 +1630,7 @@ static int tg_shares_up(struct task_group *tg, void *data)
weight = tg->cfs_rq[i]->load.weight;
usd_rq_weight[i] = weight;
+ rq_weight += weight;
/*
* If there are currently no tasks on the cpu pretend there
* is one of average load so that when a new task gets to
@@ -1638,10 +1639,13 @@ static int tg_shares_up(struct task_group *tg, void *data)
if (!weight)
weight = NICE_0_LOAD;
- rq_weight += weight;
+ sum_weight += weight;
shares += tg->cfs_rq[i]->shares;
}
+ if (!rq_weight)
+ rq_weight = sum_weight;
+
if ((!shares && rq_weight) || shares > tg->shares)
shares = tg->shares;