From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755049AbaEGGEv (ORCPT ); Wed, 7 May 2014 02:04:51 -0400 Received: from LGEMRELSE7Q.lge.com ([156.147.1.151]:42204 "EHLO lgemrelse7q.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753391AbaEGGEi (ORCPT ); Wed, 7 May 2014 02:04:38 -0400 X-Original-SENDERIP: 10.177.220.145 X-Original-MAILFROM: iamjoonsoo.kim@lge.com From: Joonsoo Kim To: Pekka Enberg Cc: Christoph Lameter , Andrew Morton , David Rientjes , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Joonsoo Kim , Joonsoo Kim Subject: [PATCH v2 01/10] slab: add unlikely macro to help compiler Date: Wed, 7 May 2014 15:06:11 +0900 Message-Id: <1399442780-28748-2-git-send-email-iamjoonsoo.kim@lge.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1399442780-28748-1-git-send-email-iamjoonsoo.kim@lge.com> References: <1399442780-28748-1-git-send-email-iamjoonsoo.kim@lge.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org slab_should_failslab() is called on every allocation, so to optimize it is reasonable. We normally don't allocate from kmem_cache. It is just used when new kmem_cache is created, so it's very rare case. Therefore, add unlikely macro to help compiler optimization. Acked-by: David Rientjes Signed-off-by: Joonsoo Kim diff --git a/mm/slab.c b/mm/slab.c index 25317fd..1fede40 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -2993,7 +2993,7 @@ static void *cache_alloc_debugcheck_after(struct kmem_cache *cachep, static bool slab_should_failslab(struct kmem_cache *cachep, gfp_t flags) { - if (cachep == kmem_cache) + if (unlikely(cachep == kmem_cache)) return false; return should_failslab(cachep->object_size, flags, cachep->flags); -- 1.7.9.5