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authorPeter Zijlstra <a.p.zijlstra@chello.nl>2010-05-31 12:37:30 +0200
committerIngo Molnar <mingo@elte.hu>2010-06-01 09:27:16 +0200
commite51fd5e22e12b39f49b1bb60b37b300b17378a43 (patch)
tree391500ff509dc30991db38e3d54eaccfe385d1cb /kernel/sched_fair.c
parent54e88fad223c4e1d94289611a90c7fe3ebe5631b (diff)
downloadop-kernel-dev-e51fd5e22e12b39f49b1bb60b37b300b17378a43.zip
op-kernel-dev-e51fd5e22e12b39f49b1bb60b37b300b17378a43.tar.gz
sched: Fix wake_affine() vs RT tasks
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>
Diffstat (limited to 'kernel/sched_fair.c')
-rw-r--r--kernel/sched_fair.c22
1 files changed, 16 insertions, 6 deletions
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 217e4a9..eed35ed 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -1225,7 +1225,6 @@ 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;
@@ -1252,8 +1251,6 @@ 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
@@ -1263,9 +1260,21 @@ 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;
/*
* If the currently running task will sleep within
@@ -2298,6 +2307,7 @@ static void update_cpu_power(struct sched_domain *sd, int cpu)
if (!power)
power = 1;
+ cpu_rq(cpu)->cpu_power = power;
sdg->cpu_power = power;
}
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