From: David Rientjes <rientjes@google.com>
Date: Wed, 29 Aug 2012 02:57:21 +0000 (-0700)
Subject: mm, slab: lock the correct nodelist after reenabling irqs
X-Git-Tag: upstream/snapshot3+hdmi~6762
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=51cd8e6ff265650e35e46b5bcbe2ee381a7a2877;p=platform%2Fadaptation%2Frenesas_rcar%2Frenesas_kernel.git

mm, slab: lock the correct nodelist after reenabling irqs

cache_grow() can reenable irqs so the cpu (and node) can change, so ensure
that we take list_lock on the correct nodelist.

This fixes an issue with commit 072bb0aa5e06 ("mm: sl[au]b: add
knowledge of PFMEMALLOC reserve pages") where list_lock for the wrong
node was taken after growing the cache.

Reported-and-tested-by: Haggai Eran <haggaie@mellanox.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/mm/slab.c b/mm/slab.c
index f8b0d53..811af03 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -3260,6 +3260,7 @@ force_grow:
 
 		/* cache_grow can reenable interrupts, then ac could change. */
 		ac = cpu_cache_get(cachep);
+		node = numa_mem_id();
 
 		/* no objects in sight? abort */
 		if (!x && (ac->avail == 0 || force_refill))