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authorVincent Guittot <vincent.guittot@linaro.org>2012-09-13 06:11:26 +0200
committerIngo Molnar <mingo@kernel.org>2012-09-13 16:52:03 +0200
commit5ed4f1d96deee82ee92cd1ac1e0108c27e80e9b0 (patch)
treeb147faa700337a1ab47a321f2e35016946b77a16
parent38b8dd6f87398524d02c21ff614c507ba8c9d295 (diff)
downloadop-kernel-dev-5ed4f1d96deee82ee92cd1ac1e0108c27e80e9b0.zip
op-kernel-dev-5ed4f1d96deee82ee92cd1ac1e0108c27e80e9b0.tar.gz
sched: Fix nohz_idle_balance()
On tickless systems, one CPU runs load balance for all idle CPUs. The cpu_load of this CPU is updated before starting the load balance of each other idle CPUs. We should instead update the cpu_load of the balance_cpu. Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Venkatesh Pallipadi <venki@google.com> Cc: Suresh Siddha <suresh.b.siddha@intel.com> Link: http://lkml.kernel.org/r/1347509486-8688-1-git-send-email-vincent.guittot@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
-rw-r--r--kernel/sched/fair.c11
1 files changed, 6 insertions, 5 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 1ca4fe4..9ae3a5b 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -4794,14 +4794,15 @@ static void nohz_idle_balance(int this_cpu, enum cpu_idle_type idle)
if (need_resched())
break;
- raw_spin_lock_irq(&this_rq->lock);
- update_rq_clock(this_rq);
- update_idle_cpu_load(this_rq);
- raw_spin_unlock_irq(&this_rq->lock);
+ rq = cpu_rq(balance_cpu);
+
+ raw_spin_lock_irq(&rq->lock);
+ update_rq_clock(rq);
+ update_idle_cpu_load(rq);
+ raw_spin_unlock_irq(&rq->lock);
rebalance_domains(balance_cpu, CPU_IDLE);
- rq = cpu_rq(balance_cpu);
if (time_after(this_rq->next_balance, rq->next_balance))
this_rq->next_balance = rq->next_balance;
}
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