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| author | Ingo Molnar <mingo@elte.hu> | 2008-11-12 20:05:50 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-11-12 20:05:50 +0100 |
| commit | 5cbd54ef470d880fc37fbe4b21eb514806d51e0d (patch) | |
| tree | db9a73e605e0a2e7cfa13bd9697a113b5f6649eb /kernel/sched.c | |
| parent | sched: fix stale value in average load per task (diff) | |
| download | linux-5cbd54ef470d880fc37fbe4b21eb514806d51e0d.tar.xz linux-5cbd54ef470d880fc37fbe4b21eb514806d51e0d.zip | |
sched: fix init_idle()'s use of sched_clock()
Maciej Rutecki reported:
> I have this bug during suspend to disk:
>
> [ 188.592151] Enabling non-boot CPUs ...
> [ 188.592151] SMP alternatives: switching to SMP code
> [ 188.666058] BUG: using smp_processor_id() in preemptible
> [00000000]
> code: suspend_to_disk/2934
> [ 188.666064] caller is native_sched_clock+0x2b/0x80
Which, as noted by Linus, was caused by me, via:
7cbaef9c "sched: optimize sched_clock() a bit"
Move the rq locking a bit earlier in the initialization sequence,
that will make the sched_clock() call in init_idle() non-preemptible.
Reported-by: Maciej Rutecki <maciej.rutecki@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/sched.c')
| -rw-r--r-- | kernel/sched.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/kernel/sched.c b/kernel/sched.c index 3bafbe350f4f..c94baf2969e7 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -5870,6 +5870,8 @@ void __cpuinit init_idle(struct task_struct *idle, int cpu) struct rq *rq = cpu_rq(cpu); unsigned long flags; + spin_lock_irqsave(&rq->lock, flags); + __sched_fork(idle); idle->se.exec_start = sched_clock(); @@ -5877,7 +5879,6 @@ void __cpuinit init_idle(struct task_struct *idle, int cpu) idle->cpus_allowed = cpumask_of_cpu(cpu); __set_task_cpu(idle, cpu); - spin_lock_irqsave(&rq->lock, flags); rq->curr = rq->idle = idle; #if defined(CONFIG_SMP) && defined(__ARCH_WANT_UNLOCKED_CTXSW) idle->oncpu = 1; |