From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,MSGID_FROM_MTA_HEADER,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 15A2AC4363A for ; Thu, 29 Oct 2020 17:10:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 88BB320759 for ; Thu, 29 Oct 2020 17:10:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=fb.com header.i=@fb.com header.b="mFHcE/Ga"; dkim=pass (1024-bit key) header.d=fb.onmicrosoft.com header.i=@fb.onmicrosoft.com header.b="k87AMIJb" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727646AbgJ2RKf (ORCPT ); Thu, 29 Oct 2020 13:10:35 -0400 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:47696 "EHLO mx0b-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726279AbgJ2RKe (ORCPT ); Thu, 29 Oct 2020 13:10:34 -0400 Received: from pps.filterd (m0109331.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 09TH984x027353; Thu, 29 Oct 2020 10:10:14 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=date : from : to : cc : subject : message-id : references : content-type : in-reply-to : mime-version; s=facebook; bh=APzs3PbGPrjNJb2CBBRZg3gOxaBp2qvf/TPBM3BJxtE=; b=mFHcE/Ganwj37eCh8LsANZiq12+Zi6jsuE7egjFBUUU0O9DPu5/U7/6VBDxVPUUjH1Ra kX+5rZkG3BFFKUjJDpZwzuqQUd9pnopvyAVCpzZARdVY6ktHvYdKa41P6yROo9EXqbXJ y1uWvYdBscLQTZ+W+xJKGMX5xyiC9rECgqg= Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com with ESMTP id 34fuvbt6f4-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT); Thu, 29 Oct 2020 10:10:14 -0700 Received: from NAM11-BN8-obe.outbound.protection.outlook.com (100.104.31.183) by o365-in.thefacebook.com (100.104.36.101) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1979.3; Thu, 29 Oct 2020 10:10:13 -0700 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=eD7GF7h83ggiZNO4vwTRfOjUnSksjQRS22I+NwA+Oc+r2gdbridTTORorFufwmz7ql9A4q8z4YGB+1Islxf/Zq9OrptoK12CfWjG0//Yw9owDzfbwhYCDOOU7+CEkHS2bGzzvd09IPFlzP8AE5pCHVdUchPB/XNouvk3Gucd9DUM5OR+jaT7Mh1RHp/9bsUuvoaSpoIJNhjuTLBD6Y/GUUaeZhiC5jA8yL70dBvWbPPLKyye+W/KhLcBHPZCeUSFx4Xm7iSDCbUHB452e3jH/Y6EQZuajUHNqUSXVmOGcDAr/+36NqFHfTBj85Ns6LzGosBtwM6IaQ/XEGwND6qAVQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=APzs3PbGPrjNJb2CBBRZg3gOxaBp2qvf/TPBM3BJxtE=; b=OwnS1T0ml8v9o0A543qZpgrrm1XAGXw7RmMsCjyXoj/fUGEEzeYhnBrfrwZv3uTDmD5arAK+C864CPAhPLC8ZXd+lDmB9u2Y+mcLxWB/NAIYoUN+cId6d4nKBsG5eqMva6PtaIcBOxcLqjxa2dYpsx8I0EbAI4X0nd8hSb1ZOIAqzUb99Z7wlitzQ4CavHumEFg1i8goyvd6VbXrbRZbMGu3ddezzccMe9qdsZ/laICWfRjNY6dSznw0rldLECENfmOv6CpwnOLyAmHDvpBi0aFNGH89jOBKQDGZhGayCD1RnnyReuUba6lFpQzFtsKSq28vQ/qTTAfBg/xm5bNcDg== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=fb.com; dmarc=pass action=none header.from=fb.com; dkim=pass header.d=fb.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.onmicrosoft.com; s=selector2-fb-onmicrosoft-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=APzs3PbGPrjNJb2CBBRZg3gOxaBp2qvf/TPBM3BJxtE=; b=k87AMIJbDtKr0USW0j7xOCtUVCgMXPDqmBOD99pWO3XL+AkPRG2mLBHEx/xdMs3Y5mTDgV9ykvQWDs6zvunh8I0DLMUTp3/69jCL7bEMWvI/H5u/L4GMUtRW7Z3IxEGssqdSQEnLCW89ozIQb4UOmEECz9BOdiuCkOs9/bx+Dm8= Authentication-Results: google.com; dkim=none (message not signed) header.d=none;google.com; dmarc=none action=none header.from=fb.com; Received: from BYAPR15MB4136.namprd15.prod.outlook.com (2603:10b6:a03:96::24) by BYAPR15MB2215.namprd15.prod.outlook.com (2603:10b6:a02:89::26) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.3499.18; Thu, 29 Oct 2020 17:10:00 +0000 Received: from BYAPR15MB4136.namprd15.prod.outlook.com ([fe80::d834:4987:4916:70f2]) by BYAPR15MB4136.namprd15.prod.outlook.com ([fe80::d834:4987:4916:70f2%5]) with mapi id 15.20.3499.027; Thu, 29 Oct 2020 17:10:00 +0000 Date: Thu, 29 Oct 2020 10:09:55 -0700 From: Roman Gushchin To: Shakeel Butt CC: Muchun Song , Johannes Weiner , Michal Hocko , Vladimir Davydov , Andrew Morton , Joonsoo Kim , Yafang Shao , Chris Down , Christian Brauner , "Peter Zijlstra (Intel)" , Ingo Molnar , Kees Cook , Thomas Gleixner , , Suren Baghdasaryan , , Marco Elver , LKML , Cgroups , Linux MM Subject: Re: [PATCH v2] mm: memcg/slab: Fix return child memcg objcg for root memcg Message-ID: <20201029170955.GI827280@carbon.dhcp.thefacebook.com> References: <20201028035013.99711-1-songmuchun@bytedance.com> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Originating-IP: [2620:10d:c090:400::4:cadf] X-ClientProxiedBy: MWHPR04CA0051.namprd04.prod.outlook.com (2603:10b6:300:6c::13) To BYAPR15MB4136.namprd15.prod.outlook.com (2603:10b6:a03:96::24) MIME-Version: 1.0 X-MS-Exchange-MessageSentRepresentingType: 1 Received: from carbon.dhcp.thefacebook.com (2620:10d:c090:400::4:cadf) by MWHPR04CA0051.namprd04.prod.outlook.com (2603:10b6:300:6c::13) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.3499.18 via Frontend Transport; Thu, 29 Oct 2020 17:09:58 +0000 X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: c442fdd4-7aa8-42c9-1b17-08d87c2d7837 X-MS-TrafficTypeDiagnostic: BYAPR15MB2215: X-Microsoft-Antispam-PRVS: X-FB-Source: Internal X-MS-Oob-TLC-OOBClassifiers: OLM:8273; X-MS-Exchange-SenderADCheck: 1 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: TD90K+B8O6Qd0kVNg2wysnHMHH83n5s06mk3+xqNmvRKRXOBfymVbOM5un75dXd+J9qkorNt1DJ0PZGVZl+XP3h1fKjjDmNraDQcdHrOwbiYMfA/xZ2RyiAk6QW9K7w9BcRN6Nt+JUKQrlfDfp35XdfnE3XqMPdkGpp3J8gVX8873rTRqsqM1aQkMOfPw/VxCeSVzg4Xtkwd7jpmlvB1FhDy3lt16pmTMCEbsLgvEi4j+9mTRyPhCitti5wdU8Jo1PrUD6or6brxFGKJ9CVS54Z1NRCQSOZK5shNvWaKkDG1dRlvh/KvKYTetHlAYO1z X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:BYAPR15MB4136.namprd15.prod.outlook.com;PTR:;CAT:NONE;SFS:(366004)(136003)(346002)(396003)(376002)(39860400002)(478600001)(7696005)(66946007)(52116002)(66476007)(8676002)(316002)(66556008)(7416002)(1076003)(6666004)(54906003)(186003)(16526019)(53546011)(5660300002)(55016002)(9686003)(6506007)(2906002)(4326008)(6916009)(8936002)(86362001)(33656002)(83380400001);DIR:OUT;SFP:1102; X-MS-Exchange-AntiSpam-MessageData: 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 X-MS-Exchange-CrossTenant-Network-Message-Id: c442fdd4-7aa8-42c9-1b17-08d87c2d7837 X-MS-Exchange-CrossTenant-AuthSource: BYAPR15MB4136.namprd15.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 29 Oct 2020 17:10:00.7073 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 8ae927fe-1255-47a7-a2af-5f3a069daaa2 X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: y4QCob6BDAebqvAJLhgcFfEqOWCC4OHJruiuK0Q6PRY3Okcl6FmdeM6b25fxQq1r X-MS-Exchange-Transport-CrossTenantHeadersStamped: BYAPR15MB2215 X-OriginatorOrg: fb.com X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.312,18.0.737 definitions=2020-10-29_11:2020-10-29,2020-10-29 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 priorityscore=1501 phishscore=0 malwarescore=0 mlxlogscore=999 impostorscore=0 adultscore=0 suspectscore=1 bulkscore=0 clxscore=1015 spamscore=0 lowpriorityscore=0 mlxscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2010290119 X-FB-Internal: deliver Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 29, 2020 at 08:48:45AM -0700, Shakeel Butt wrote: > On Tue, Oct 27, 2020 at 8:50 PM Muchun Song wrote: > > > > Consider the following memcg hierarchy. > > > > root > > / \ > > A B > > > > If we get the objcg of memcg A failed, > > Please fix the above statement. > > > the get_obj_cgroup_from_current > > can return the wrong objcg for the root memcg. > > > > Fixes: bf4f059954dc ("mm: memcg/slab: obj_cgroup API") > > Signed-off-by: Muchun Song > > --- > > changelog in v2: > > 1. Do not use a comparison with the root_mem_cgroup > > > > mm/memcontrol.c | 1 + > > 1 file changed, 1 insertion(+) > > > > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > > index 1337775b04f3..8c8b4c3ed5a0 100644 > > --- a/mm/memcontrol.c > > +++ b/mm/memcontrol.c > > @@ -2961,6 +2961,7 @@ __always_inline struct obj_cgroup *get_obj_cgroup_from_current(void) > > objcg = rcu_dereference(memcg->objcg); > > if (objcg && obj_cgroup_tryget(objcg)) > > break; > > + objcg = NULL; > > Roman, in your cleanup, are you planning to have objcg for root memcg as well? Yes. I'll just change the for loop to include the root_mem_cgroup. Thanks! From mboxrd@z Thu Jan 1 00:00:00 1970 From: Roman Gushchin Subject: Re: [PATCH v2] mm: memcg/slab: Fix return child memcg objcg for root memcg Date: Thu, 29 Oct 2020 10:09:55 -0700 Message-ID: <20201029170955.GI827280@carbon.dhcp.thefacebook.com> References: <20201028035013.99711-1-songmuchun@bytedance.com> Mime-Version: 1.0 Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=date : from : to : cc : subject : message-id : references : content-type : in-reply-to : mime-version; s=facebook; bh=APzs3PbGPrjNJb2CBBRZg3gOxaBp2qvf/TPBM3BJxtE=; b=mFHcE/Ganwj37eCh8LsANZiq12+Zi6jsuE7egjFBUUU0O9DPu5/U7/6VBDxVPUUjH1Ra kX+5rZkG3BFFKUjJDpZwzuqQUd9pnopvyAVCpzZARdVY6ktHvYdKa41P6yROo9EXqbXJ y1uWvYdBscLQTZ+W+xJKGMX5xyiC9rECgqg= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.onmicrosoft.com; s=selector2-fb-onmicrosoft-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=APzs3PbGPrjNJb2CBBRZg3gOxaBp2qvf/TPBM3BJxtE=; b=k87AMIJbDtKr0USW0j7xOCtUVCgMXPDqmBOD99pWO3XL+AkPRG2mLBHEx/xdMs3Y5mTDgV9ykvQWDs6zvunh8I0DLMUTp3/69jCL7bEMWvI/H5u/L4GMUtRW7Z3IxEGssqdSQEnLCW89ozIQb4UOmEECz9BOdiuCkOs9/bx+Dm8= Content-Disposition: inline In-Reply-To: List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Shakeel Butt Cc: Muchun Song , Johannes Weiner , Michal Hocko , Vladimir Davydov , Andrew Morton , Joonsoo Kim , Yafang Shao , Chris Down , Christian Brauner , "Peter Zijlstra (Intel)" , Ingo Molnar , Kees Cook , Thomas Gleixner , esyr@redhat.com, Suren Baghdasaryan , areber@redhat.com, Marco Elver , LKML , Cgroups , Linux MM On Thu, Oct 29, 2020 at 08:48:45AM -0700, Shakeel Butt wrote: > On Tue, Oct 27, 2020 at 8:50 PM Muchun Song wrote: > > > > Consider the following memcg hierarchy. > > > > root > > / \ > > A B > > > > If we get the objcg of memcg A failed, > > Please fix the above statement. > > > the get_obj_cgroup_from_current > > can return the wrong objcg for the root memcg. > > > > Fixes: bf4f059954dc ("mm: memcg/slab: obj_cgroup API") > > Signed-off-by: Muchun Song > > --- > > changelog in v2: > > 1. Do not use a comparison with the root_mem_cgroup > > > > mm/memcontrol.c | 1 + > > 1 file changed, 1 insertion(+) > > > > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > > index 1337775b04f3..8c8b4c3ed5a0 100644 > > --- a/mm/memcontrol.c > > +++ b/mm/memcontrol.c > > @@ -2961,6 +2961,7 @@ __always_inline struct obj_cgroup *get_obj_cgroup_from_current(void) > > objcg = rcu_dereference(memcg->objcg); > > if (objcg && obj_cgroup_tryget(objcg)) > > break; > > + objcg = NULL; > > Roman, in your cleanup, are you planning to have objcg for root memcg as well? Yes. I'll just change the for loop to include the root_mem_cgroup. Thanks!