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From: Cyrill Gorcunov <gorcunov@gmail.com>
To: Christoph Lameter <cl@linux-foundation.org>,
	Pekka Enberg <penberg@cs.helsinki.fi>
Cc: LKML <linux-kernel@vger.kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>
Subject: mm: slab - __cache_alloc NULL prefetch fix
Date: Thu, 20 Nov 2008 19:44:00 +0300	[thread overview]
Message-ID: <20081120164400.GC7363@localhost> (raw)

Do not prefetch NULL

Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
---

Please check

 mm/slab.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

Index: linux-2.6.git/mm/slab.c
===================================================================
--- linux-2.6.git.orig/mm/slab.c
+++ linux-2.6.git/mm/slab.c
@@ -3395,10 +3395,11 @@ __cache_alloc(struct kmem_cache *cachep,
 	objp = __do_cache_alloc(cachep, flags);
 	local_irq_restore(save_flags);
 	objp = cache_alloc_debugcheck_after(cachep, flags, objp, caller);
-	prefetchw(objp);
 
-	if (likely(objp))
+	if (likely(objp)) {
+		prefetchw(objp);
 		kmemcheck_slab_alloc(cachep, flags, objp, obj_size(cachep));
+	}
 
 	if (unlikely((flags & __GFP_ZERO) && objp))
 		memset(objp, 0, obj_size(cachep));

             reply	other threads:[~2008-11-20 16:44 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-11-20 16:44 Cyrill Gorcunov [this message]
2008-11-20 17:01 ` mm: slab - __cache_alloc NULL prefetch fix Cyrill Gorcunov
2008-11-20 18:16   ` Christoph Lameter
2008-11-20 18:24     ` Cyrill Gorcunov
2008-11-20 18:15 ` Christoph Lameter
2008-11-20 19:58 ` Valdis.Kletnieks
2008-11-20 20:03   ` Pekka Enberg
2008-11-20 20:10   ` Cyrill Gorcunov

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