From: shin, jacob <jacob.shin@amd.com>
Date: Fri, 28 Apr 2006 15:54:37 +0000 (-0500)
Subject: [PATCH] slab: fix crash on __drain_alien_cahce() during CPU Hotplug
X-Git-Tag: v2.6.17-rc4~109
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=693f7d362055261882659475d2ef022e32edbff1;p=linux-2.6

[PATCH] slab: fix crash on __drain_alien_cahce() during CPU Hotplug

transfer_objects should only be called when all of the cpus in the
node are online.  CPU_DEAD notifier callback marks l3->shared to NULL.

Signed-off-by: Jacob Shin <jacob.shin@amd.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---

diff --git a/mm/slab.c b/mm/slab.c
index af5c5237e1..c32af7e758 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -979,7 +979,8 @@ static void __drain_alien_cache(struct kmem_cache *cachep,
 		 * That way we could avoid the overhead of putting the objects
 		 * into the free lists and getting them back later.
 		 */
-		transfer_objects(rl3->shared, ac, ac->limit);
+		if (rl3->shared)
+			transfer_objects(rl3->shared, ac, ac->limit);
 
 		free_block(cachep, ac->entry, ac->avail, node);
 		ac->avail = 0;