forked from rrcarlosr/Jetpack
42 lines
1.2 KiB
Diff
42 lines
1.2 KiB
Diff
From 31a49dc48c7d93fa6160e9efba44948944aeb732 Mon Sep 17 00:00:00 2001
|
|
From: Yong Zhang <yong.zhang0@gmail.com>
|
|
Date: Thu, 28 Jul 2011 11:16:00 +0800
|
|
Subject: [PATCH 147/352] 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>
|
|
---
|
|
kernel/cpu.c | 4 +++-
|
|
1 file changed, 3 insertions(+), 1 deletion(-)
|
|
|
|
diff --git a/kernel/cpu.c b/kernel/cpu.c
|
|
index de4d685..ee08823 100644
|
|
--- a/kernel/cpu.c
|
|
+++ b/kernel/cpu.c
|
|
@@ -264,9 +264,11 @@ static DEFINE_PER_CPU(struct hotplug_pcp, hotplug_pcp);
|
|
*/
|
|
void pin_current_cpu(void)
|
|
{
|
|
- struct hotplug_pcp *hp = this_cpu_ptr(&hotplug_pcp);
|
|
+ struct hotplug_pcp *hp;
|
|
|
|
retry:
|
|
+ hp = this_cpu_ptr(&hotplug_pcp);
|
|
+
|
|
if (!hp->unplug || hp->refcount || preempt_count() > 1 ||
|
|
hp->unplug == current) {
|
|
hp->refcount++;
|
|
--
|
|
2.7.4
|
|
|