[PATCH] Fix the spurious unlock_cpu_hotplug false warnings
Cpu-hotplug locking has a minor race case caused because of setting the
variable "recursive" to NULL *after* releasing the cpu_bitmask_lock in the
function unlock_cpu_hotplug,instead of doing so before releasing the
cpu_bitmask_lock.
This was the cause of most of the recent false spurious lock_cpu_unlock
warnings.
This should fix the problem reported by Martin Lorenz reported in
http://lkml.org/lkml/2006/10/29/127.
Thanks to Srinivasa DS for pointing it out.
Signed-off-by: Gautham R Shenoy <ego@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/kernel/cpu.c b/kernel/cpu.c
index 663c920..272254f 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -58,8 +58,8 @@
recursive_depth--;
return;
}
- mutex_unlock(&cpu_bitmask_lock);
recursive = NULL;
+ mutex_unlock(&cpu_bitmask_lock);
}
EXPORT_SYMBOL_GPL(unlock_cpu_hotplug);