diff options
| author | Yong Zhang <yong.zhang0@gmail.com> | 2011-07-28 11:16:00 +0800 |
|---|---|---|
| committer | Clark Williams <williams@redhat.com> | 2012-04-13 11:01:36 -0500 |
| commit | 300df92ef1b8fb347eca53aed4520f9dcb4bc701 (patch) | |
| tree | e1f601182d8a08f99d8f07bc453eaaf088729c06 /kernel/cpu.c | |
| parent | dc5bf47fd7183841fa542decb72656c55d7829c5 (diff) | |
hotplug: Reread hotplug_pcp on pin_current_cpu() retry
When retry happens, it's likely that the task has been migrated to
another cpu (except unplug failed), but it still derefernces the
original hotplug_pcp per cpu data.
Update the pointer to hotplug_pcp in the retry path, so it points to
the current cpu.
Signed-off-by: Yong Zhang <yong.zhang0@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20110728031600.GA338@windriver.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'kernel/cpu.c')
| -rw-r--r-- | kernel/cpu.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/kernel/cpu.c b/kernel/cpu.c index da4ed4f5aacd..1e80dff9b225 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -76,9 +76,11 @@ static DEFINE_PER_CPU(struct hotplug_pcp, hotplug_pcp); */ void pin_current_cpu(void) { - struct hotplug_pcp *hp = &__get_cpu_var(hotplug_pcp); + struct hotplug_pcp *hp; retry: + hp = &__get_cpu_var(hotplug_pcp); + if (!hp->unplug || hp->refcount || preempt_count() > 1 || hp->unplug == current || (current->flags & PF_STOMPER)) { hp->refcount++; |