diff options
| author | Yong Zhang <yong.zhang0@gmail.com> | 2011-07-28 11:16:00 +0800 |
|---|---|---|
| committer | Clark Williams <williams@redhat.com> | 2012-03-07 16:15:03 -0600 |
| commit | 384d7c97ba8f128aadc4e3513349ecad9caedd62 (patch) | |
| tree | 4181b3cb481721baf53e09bad18177567c0e8468 /kernel/cpu.c | |
| parent | f3ccd7bebc5caf729d8b116e63df319c3befdd12 (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 171cb6ce29c7..80c72da6af95 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++; |