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| author | Yong Zhang <yong.zhang0@gmail.com> | 2011-07-28 03:16:00 (GMT) |
|---|---|---|
| committer | Scott Wood <scottwood@freescale.com> | 2014-04-10 00:19:14 (GMT) |
| commit | f31b617a9cfe6498b9ebc27187fee5385c17e337 (patch) | |
| tree | 5ce7cdba60adbd10cc4782f97b8d4e49a0f1d344 /kernel/cpu.c | |
| parent | 24ff554021113fcf827e3aac0bca57956fb169a3 (diff) | |
| download | linux-fsl-qoriq-f31b617a9cfe6498b9ebc27187fee5385c17e337.tar.xz | |
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 7de9868..b9c39b5 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -81,9 +81,11 @@ 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) { hp->refcount++; |