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 <[email protected]>
--
kernel/cpu.c | 2 +-
1 files changed, 1 insertion(+), 1 deletion(-)
Index: hotplug/kernel/cpu.c
===================================================================
--- hotplug.orig/kernel/cpu.c
+++ hotplug/kernel/cpu.c
@@ -58,8 +58,8 @@ void unlock_cpu_hotplug(void)
recursive_depth--;
return;
}
- mutex_unlock(&cpu_bitmask_lock);
recursive = NULL;
+ mutex_unlock(&cpu_bitmask_lock);
}
EXPORT_SYMBOL_GPL(unlock_cpu_hotplug);
--
Gautham R Shenoy
Linux Technology Center
IBM India.
"Freedom comes with a price tag of responsibility, which is still a bargain,
because Freedom is priceless!"