Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...

[pandora-kernel.git] / mm / ksm.c

diff --git a/mm/ksm.c b/mm/ksm.c
index 65ab5c7..43bc893 100644 (file)
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -1724,8 +1724,13 @@ static int ksm_memory_callback(struct notifier_block *self,
                /*
                 * Keep it very simple for now: just lock out ksmd and
                 * MADV_UNMERGEABLE while any memory is going offline.
+                * mutex_lock_nested() is necessary because lockdep was alarmed
+                * that here we take ksm_thread_mutex inside notifier chain
+                * mutex, and later take notifier chain mutex inside
+                * ksm_thread_mutex to unlock it.   But that's safe because both
+                * are inside mem_hotplug_mutex.
                 */
-               mutex_lock(&ksm_thread_mutex);
+               mutex_lock_nested(&ksm_thread_mutex, SINGLE_DEPTH_NESTING);
                break;
 
        case MEM_OFFLINE: