From patchwork Tue Mar 4 22:13:47 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mikulas Patocka X-Patchwork-Id: 3768901 Return-Path: X-Original-To: patchwork-dm-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id C2965BF13A for ; Tue, 4 Mar 2014 22:18:39 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id EEAA720222 for ; Tue, 4 Mar 2014 22:18:38 +0000 (UTC) Received: from mx3-phx2.redhat.com (mx3-phx2.redhat.com [209.132.183.24]) by mail.kernel.org (Postfix) with ESMTP id 236F920221 for ; Tue, 4 Mar 2014 22:18:38 +0000 (UTC) Received: from lists01.pubmisc.prod.ext.phx2.redhat.com (lists01.pubmisc.prod.ext.phx2.redhat.com [10.5.19.33]) by mx3-phx2.redhat.com (8.13.8/8.13.8) with ESMTP id s24MDqiO022303; Tue, 4 Mar 2014 17:13:54 -0500 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by lists01.pubmisc.prod.ext.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id s24MDmap004955 for ; Tue, 4 Mar 2014 17:13:48 -0500 Received: from file01.intranet.prod.int.rdu2.redhat.com (file01.intranet.prod.int.rdu2.redhat.com [10.11.5.7]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id s24MDlqK019183 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Tue, 4 Mar 2014 17:13:48 -0500 Received: from file01.intranet.prod.int.rdu2.redhat.com (localhost [127.0.0.1]) by file01.intranet.prod.int.rdu2.redhat.com (8.14.4/8.14.4) with ESMTP id s24MDlXQ029538; Tue, 4 Mar 2014 17:13:47 -0500 Received: from localhost (mpatocka@localhost) by file01.intranet.prod.int.rdu2.redhat.com (8.14.4/8.14.4/Submit) with ESMTP id s24MDlii029534; Tue, 4 Mar 2014 17:13:47 -0500 X-Authentication-Warning: file01.intranet.prod.int.rdu2.redhat.com: mpatocka owned process doing -bs Date: Tue, 4 Mar 2014 17:13:47 -0500 (EST) From: Mikulas Patocka X-X-Sender: mpatocka@file01.intranet.prod.int.rdu2.redhat.com To: Christoph Lameter Message-ID: User-Agent: Alpine 2.02 (LRH 1266 2009-07-14) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.68 on 10.5.11.23 X-loop: dm-devel@redhat.com Cc: Pekka Enberg , linux-mm@kvack.org, dm-devel@redhat.com, "Alasdair G. Kergon" Subject: [dm-devel] [PATCH] slab_common: fix the check for duplicate slab names X-BeenThere: dm-devel@redhat.com X-Mailman-Version: 2.1.12 Precedence: junk Reply-To: device-mapper development List-Id: device-mapper development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The patch 3e374919b314f20e2a04f641ebc1093d758f66a4 is supposed to fix the problem where kmem_cache_create incorrectly reports duplicate cache name and fails. The problem is described in the header of that patch. However, the patch doesn't really fix the problem because of these reasons: * the logic to test for debugging is reversed. It was intended to perform the check only if slub debugging is enabled (which implies that caches with the same parameters are not merged). Therefore, there should be #if !defined(CONFIG_SLUB) || defined(CONFIG_SLUB_DEBUG_ON) The current code has the condition reversed and performs the test if debugging is disabled. * slub debugging may be enabled or disabled based on kernel command line, CONFIG_SLUB_DEBUG_ON is just the default settings. Therefore the test based on definition of CONFIG_SLUB_DEBUG_ON is unreliable. This patch fixes the problem by removing the test "!defined(CONFIG_SLUB_DEBUG_ON)". Therefore, duplicate names are never checked if the SLUB allocator is used. Note to stable kernel maintainers: when backporint this patch, please backport also the patch 3e374919b314f20e2a04f641ebc1093d758f66a4. Signed-off-by: Mikulas Patocka Cc: stable@vger.kernel.org # 3.6+ Acked-by: David Rientjes Acked-by: Christoph Lameter --- mm/slab_common.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) -- dm-devel mailing list dm-devel@redhat.com https://www.redhat.com/mailman/listinfo/dm-devel Index: linux-3.14-rc5/mm/slab_common.c =================================================================== --- linux-3.14-rc5.orig/mm/slab_common.c 2014-03-04 22:47:02.000000000 +0100 +++ linux-3.14-rc5/mm/slab_common.c 2014-03-04 22:47:08.000000000 +0100 @@ -56,7 +56,7 @@ static int kmem_cache_sanity_check(struc continue; } -#if !defined(CONFIG_SLUB) || !defined(CONFIG_SLUB_DEBUG_ON) +#if !defined(CONFIG_SLUB) /* * For simplicity, we won't check this in the list of memcg * caches. We have control over memcg naming, and if there