diff options
| author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2011-02-10 10:23:29 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2011-02-17 15:37:30 -0800 |
| commit | 97fc6c0d4655abc7ab58dc4c065b5f3fcde2fc6b (patch) | |
| tree | 2946cbf0965aa9025c825b19840f2b50e2914135 /kernel/sched_fair.c | |
| parent | 354f5613d804571fa88ecff8eec02d5ba57d8b07 (diff) | |
sched: Fix wake_affine() vs RT tasks
Commit: e51fd5e22e12b39f49b1bb60b37b300b17378a43 upstream
Mike reports that since e9e9250b (sched: Scale down cpu_power due to RT
tasks), wake_affine() goes funny on RT tasks due to them still having a
!0 weight and wake_affine() still subtracts that from the rq weight.
Since nobody should be using se->weight for RT tasks, set the value to
zero. Also, since we now use ->cpu_power to normalize rq weights to
account for RT cpu usage, add that factor into the imbalance computation.
Reported-by: Mike Galbraith <efault@gmx.de>
Tested-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1275316109.27810.22969.camel@twins>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'kernel/sched_fair.c')
| -rw-r--r-- | kernel/sched_fair.c | 22 |
1 files changed, 16 insertions, 6 deletions
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 4e0aca002bb..cd9a40b5d50 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -1222,7 +1222,6 @@ static int wake_affine(struct sched_domain *sd, struct task_struct *p, int sync) unsigned long this_load, load; int idx, this_cpu, prev_cpu; unsigned long tl_per_task; - unsigned int imbalance; struct task_group *tg; unsigned long weight; int balanced; @@ -1262,8 +1261,6 @@ static int wake_affine(struct sched_domain *sd, struct task_struct *p, int sync) tg = task_group(p); weight = p->se.load.weight; - imbalance = 100 + (sd->imbalance_pct - 100) / 2; - /* * In low-load situations, where prev_cpu is idle and this_cpu is idle * due to the sync cause above having dropped this_load to 0, we'll @@ -1273,9 +1270,22 @@ static int wake_affine(struct sched_domain *sd, struct task_struct *p, int sync) * Otherwise check if either cpus are near enough in load to allow this * task to be woken on this_cpu. */ - balanced = !this_load || - 100*(this_load + effective_load(tg, this_cpu, weight, weight)) <= - imbalance*(load + effective_load(tg, prev_cpu, 0, weight)); + if (this_load) { + unsigned long this_eff_load, prev_eff_load; + + this_eff_load = 100; + this_eff_load *= power_of(prev_cpu); + this_eff_load *= this_load + + effective_load(tg, this_cpu, weight, weight); + + prev_eff_load = 100 + (sd->imbalance_pct - 100) / 2; + prev_eff_load *= power_of(this_cpu); + prev_eff_load *= load + effective_load(tg, prev_cpu, 0, weight); + + balanced = this_eff_load <= prev_eff_load; + } else + balanced = true; + rcu_read_unlock(); /* |