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sched: Fix/add missing update_rq_clock() calls 

kthread_bind(), migrate_task() and sched_fork were missing
updates, and try_to_wake_up() was updating after having already
used the stale clock.

Aside from preventing potential latency hits, there' a side
benefit in that early boot printk time stamps become monotonic.

Signed-off-by: Mike Galbraith <efault@gmx.de>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1258020464.6491.2.camel@marge.simson.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
LKML-Reference: <new-submission>
This commit is contained in:
Mike Galbraith 2009-11-12 11:07:44 +01:00 committed by Ingo Molnar
parent aa021baa32
commit 055a00865d
1 changed files with 13 additions and 6 deletions
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19
kernel/sched.c
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@ -2017,6 +2017,7 @@ void kthread_bind(struct task_struct *p, unsigned int cpu)
}
spin_lock_irqsave(&rq->lock, flags);
update_rq_clock(rq);
set_task_cpu(p, cpu);
p->cpus_allowed = cpumask_of_cpu(cpu);
p->rt.nr_cpus_allowed = 1;
@ -2115,6 +2116,7 @@ migrate_task(struct task_struct *p, int dest_cpu, struct migration_req *req)
* it is sufficient to simply update the task's cpu field.
*/
if (!p->se.on_rq && !task_running(rq, p)) {
update_rq_clock(rq);
set_task_cpu(p, dest_cpu);
return 0;
}
@ -2376,13 +2378,14 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state,
task_rq_unlock(rq, &flags);
cpu = p->sched_class->select_task_rq(p, SD_BALANCE_WAKE, wake_flags);
if (cpu != orig_cpu)
set_task_cpu(p, cpu);
rq = task_rq_lock(p, &flags);
if (rq != orig_rq)
if (cpu != orig_cpu) {
local_irq_save(flags);
rq = cpu_rq(cpu);
update_rq_clock(rq);
set_task_cpu(p, cpu);
local_irq_restore(flags);
}
rq = task_rq_lock(p, &flags);
WARN_ON(p->state != TASK_WAKING);
cpu = task_cpu(p);
@ -2545,6 +2548,7 @@ static void __sched_fork(struct task_struct *p)
void sched_fork(struct task_struct *p, int clone_flags)
{
int cpu = get_cpu();
unsigned long flags;
__sched_fork(p);
@ -2581,7 +2585,10 @@ void sched_fork(struct task_struct *p, int clone_flags)
#ifdef CONFIG_SMP
cpu = p->sched_class->select_task_rq(p, SD_BALANCE_FORK, 0);
#endif
local_irq_save(flags);
update_rq_clock(cpu_rq(cpu));
set_task_cpu(p, cpu);
local_irq_restore(flags);
#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
if (likely(sched_info_on()))