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authorThomas Gleixner <tglx@linutronix.de>2009-07-17 14:15:46 +0200
committerThomas Gleixner <tglx@linutronix.de>2009-07-18 14:19:52 +0200
commita468d389349a7560249b355cdb6d2097ea1616c9 (patch)
treef385d5847644dfdde3fb441b8e4430ac9024d0ab /kernel
parent54fdc5816631b43ba55fc3206d7add2d85850bc6 (diff)
downloadlinux-a468d389349a7560249b355cdb6d2097ea1616c9.tar.bz2
sched: fix load average accounting vs. cpu hotplug
The new load average code clears rq->calc_load_active on CPU_ONLINE. That's wrong as the new onlined CPU might have got a scheduler tick already and accounted the delta to the stale value of the time we offlined the CPU. Clear the value when we cleanup the dead CPU instead. Also move the update of the calc_load_update time for the newly online CPU to CPU_UP_PREPARE to avoid that the CPU plays catch up with the stale update time value. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/sched.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/sched.c b/kernel/sched.c
index 98972d366fdc..1b59e265273b 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -7289,6 +7289,7 @@ static void migrate_dead_tasks(unsigned int dead_cpu)
static void calc_global_load_remove(struct rq *rq)
{
atomic_long_sub(rq->calc_load_active, &calc_load_tasks);
+ rq->calc_load_active = 0;
}
#endif /* CONFIG_HOTPLUG_CPU */
@@ -7515,6 +7516,7 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
task_rq_unlock(rq, &flags);
get_task_struct(p);
cpu_rq(cpu)->migration_thread = p;
+ rq->calc_load_update = calc_load_update;
break;
case CPU_ONLINE:
@@ -7525,8 +7527,6 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
/* Update our root-domain */
rq = cpu_rq(cpu);
spin_lock_irqsave(&rq->lock, flags);
- rq->calc_load_update = calc_load_update;
- rq->calc_load_active = 0;
if (rq->rd) {
BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span));