From patchwork Wed Dec 18 07:21:17 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Joonsoo Kim X-Patchwork-Id: 3368331 Return-Path: X-Original-To: patchwork-linux-arm@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 4193AC0D4A for ; Wed, 18 Dec 2013 07:21:58 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 64A4E203EC for ; Wed, 18 Dec 2013 07:21:57 +0000 (UTC) Received: from casper.infradead.org (casper.infradead.org [85.118.1.10]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 08658203EB for ; Wed, 18 Dec 2013 07:21:56 +0000 (UTC) Received: from merlin.infradead.org ([2001:4978:20e::2]) by casper.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1VtBS2-0000AM-HU; Wed, 18 Dec 2013 07:21:50 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1VtBRz-0005Co-KC; Wed, 18 Dec 2013 07:21:47 +0000 Received: from lgeamrelo02.lge.com ([156.147.1.126]) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1VtBRv-0005C9-87 for linux-arm-kernel@lists.infradead.org; Wed, 18 Dec 2013 07:21:44 +0000 X-AuditID: 9c93017e-b7c17ae000003961-e7-52b14cedb344 Received: from lge.com ( [10.177.220.200]) by LGEAMRELO02.lge.com (Symantec Brightmail Gateway) with SMTP id CB.E2.14689.DEC41B25; Wed, 18 Dec 2013 16:21:18 +0900 (KST) Date: Wed, 18 Dec 2013 16:21:17 +0900 From: Joonsoo Kim To: linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-mmc@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: possible regression on 3.13 when calling flush_dcache_page Message-ID: <20131218072117.GA2383@lge.com> References: <20131212143149.GI12099@ldesroches-Latitude-E6320> <20131212143618.GJ12099@ldesroches-Latitude-E6320> <20131213015909.GA8845@lge.com> <20131216144343.GD9627@ldesroches-Latitude-E6320> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20131216144343.GD9627@ldesroches-Latitude-E6320> User-Agent: Mutt/1.5.21 (2010-09-15) X-Brightmail-Tracker: AAAAAA== X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20131218_022143_529533_B2841FCA X-CRM114-Status: GOOD ( 24.07 ) X-Spam-Score: -2.4 (--) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-4.7 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, 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 On Mon, Dec 16, 2013 at 03:43:43PM +0100, Ludovic Desroches wrote: > Hello, > > On Fri, Dec 13, 2013 at 10:59:09AM +0900, Joonsoo Kim wrote: > > On Thu, Dec 12, 2013 at 03:36:19PM +0100, Ludovic Desroches wrote: > > > fix mmc mailing list address error > > > > > > On Thu, Dec 12, 2013 at 03:31:50PM +0100, Ludovic Desroches wrote: > > > > Hi, > > > > > > > > With v3.13-rc3 I have an error when the atmel-mci driver calls > > > > flush_dcache_page (log at the end of the message). > > > > > > > > Since I didn't have it before, I did a git bisect and the commit introducing > > > > the error is the following one: > > > > > > > > 106a74e slab: replace free and inuse in struct slab with newly introduced active > > > > > > > > I don't know if this commit has introduced a bug or if it has revealed a bug > > > > in the atmel-mci driver. > > > > Hello, > > > > I think that this commit may not introduce a bug. This patch remove one > > variable on slab management structure and replace variable name. So there > > is no functional change. > > > > If I have reverted this patch and other ones you did on top of it and > the issue disappear. Hello, Could you give me your '/proc/slabinfo' before/after this commit (106a74e)? And how about testing with artificially increasing size of struct slab on top of this commit (106a74e)? I really wonder why the problem happens, because this doesn't cause any functional change as far as I know. Only side-effect from this patch is decreasing size of struct slab. Thanks. > > > I doubt that side-effect of this patch reveals a bug in other place. > > Side-effect is reduced memory usage for slab management structure. It would > > makes some slabs have more objects with more density since slab management > > structure is sometimes on the page for objects. So if it diminishes, more > > objects can be in the page. > > > > Anyway, I will look at it more. If you have any progress, please let me know. > > No progress at the moment. diff --git a/mm/slab.c b/mm/slab.c index 2ec2336..d2240fd 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -174,6 +174,7 @@ struct slab { struct { struct list_head list; void *s_mem; /* including colour offset */ + unsigned int x; unsigned int active; /* num of objs active in slab */ }; };