From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933168AbdIYBXh (ORCPT ); Sun, 24 Sep 2017 21:23:37 -0400 Received: from omzsmtpe01.verizonbusiness.com ([199.249.25.210]:52133 "EHLO omzsmtpe01.verizonbusiness.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933643AbdIYBOk (ORCPT ); Sun, 24 Sep 2017 21:14:40 -0400 From: "Levin, Alexander (Sasha Levin)" Cc: Grygorii Maistrenko , Joonsoo Kim , Andrew Morton , "Linus Torvalds" , "Levin, Alexander (Sasha Levin)" X-Host: viking.odc.vzwcorp.com To: "linux-kernel@vger.kernel.org" , "stable@vger.kernel.org" Subject: [PATCH review for 4.4 16/26] slub: do not merge cache if slub_debug contains a never-merge flag Thread-Topic: [PATCH review for 4.4 16/26] slub: do not merge cache if slub_debug contains a never-merge flag Thread-Index: AQHTNZuGpD3ymW+jHk+6E6KwlYZEdw== Date: Mon, 25 Sep 2017 01:13:42 +0000 Message-ID: <20170925011322.10133-16-alexander.levin@verizon.com> References: <20170925011322.10133-1-alexander.levin@verizon.com> In-Reply-To: <20170925011322.10133-1-alexander.levin@verizon.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-messagesentrepresentingtype: 1 x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.144.60.250] Content-Type: text/plain; charset="iso-8859-1" MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by nfs id v8P1Pljl015179 From: Grygorii Maistrenko [ Upstream commit c6e28895a4372992961888ffaadc9efc643b5bfe ] In case CONFIG_SLUB_DEBUG_ON=n, find_mergeable() gets debug features from commandline but never checks if there are features from the SLAB_NEVER_MERGE set. As a result selected by slub_debug caches are always mergeable if they have been created without a custom constructor set or without one of the SLAB_* debug features on. This moves the SLAB_NEVER_MERGE check below the flags update from commandline to make sure it won't merge the slab cache if one of the debug features is on. Link: http://lkml.kernel.org/r/20170101124451.GA4740@lp-laptop-d Signed-off-by: Grygorii Maistrenko Reviewed-by: Pekka Enberg Acked-by: David Rientjes Acked-by: Christoph Lameter Cc: Joonsoo Kim Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- mm/slab_common.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/mm/slab_common.c b/mm/slab_common.c index bec2fce9fafc..01e7246de8df 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -250,7 +250,7 @@ struct kmem_cache *find_mergeable(size_t size, size_t align, { struct kmem_cache *s; - if (slab_nomerge || (flags & SLAB_NEVER_MERGE)) + if (slab_nomerge) return NULL; if (ctor) @@ -261,6 +261,9 @@ struct kmem_cache *find_mergeable(size_t size, size_t align, size = ALIGN(size, align); flags = kmem_cache_flags(size, flags, name, NULL); + if (flags & SLAB_NEVER_MERGE) + return NULL; + list_for_each_entry_reverse(s, &slab_caches, list) { if (slab_unmergeable(s)) continue; -- 2.11.0