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=-3.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 BE276CA9ECB for ; Thu, 31 Oct 2019 15:49:37 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 66D122087F for ; Thu, 31 Oct 2019 15:49:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=fb.com header.i=@fb.com header.b="B4wSRYAW"; dkim=pass (1024-bit key) header.d=fb.onmicrosoft.com header.i=@fb.onmicrosoft.com header.b="kB9jWepP" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 66D122087F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=fb.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 005A26B0003; Thu, 31 Oct 2019 11:49:37 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id EF8876B0005; Thu, 31 Oct 2019 11:49:36 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D98CC6B0007; Thu, 31 Oct 2019 11:49:36 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0110.hostedemail.com [216.40.44.110]) by kanga.kvack.org (Postfix) with ESMTP id B8F036B0003 for ; Thu, 31 Oct 2019 11:49:36 -0400 (EDT) Received: from smtpin08.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with SMTP id 412492C6D for ; Thu, 31 Oct 2019 15:49:36 +0000 (UTC) X-FDA: 76104514752.08.bit77_8df2feecfba01 X-HE-Tag: bit77_8df2feecfba01 X-Filterd-Recvd-Size: 10566 Received: from mx0a-00082601.pphosted.com (mx0a-00082601.pphosted.com [67.231.145.42]) by imf08.hostedemail.com (Postfix) with ESMTP for ; Thu, 31 Oct 2019 15:49:35 +0000 (UTC) Received: from pps.filterd (m0109333.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id x9VFjB4P024794; Thu, 31 Oct 2019 08:49:28 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : references : in-reply-to : content-type : content-id : content-transfer-encoding : mime-version; s=facebook; bh=ME/H1ACHPe24OMG3vl1RUw07lFiay8ALqV0QNsz8HoE=; b=B4wSRYAWQGVLYISENFhwLuTFQSMg8kDBc+cx9/5hCXRViMejxRI4dBfyrEmZDGIgN5Y0 R+6yLBlZbZwfPqAaZqjxdK9mMfMM+WM9cmMmN7x57xsIYuD6JB05gx7xPD0srwR3dkj0 j8pcfZyRMP6tukM3vjQqyRxwnwWaCX38NtE= Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com with ESMTP id 2w01c4re2u-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT); Thu, 31 Oct 2019 08:49:27 -0700 Received: from ash-exopmbx201.TheFacebook.com (2620:10d:c0a8:83::8) by ash-exhub102.TheFacebook.com (2620:10d:c0a8:82::f) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1713.5; Thu, 31 Oct 2019 08:49:26 -0700 Received: from ash-exhub103.TheFacebook.com (2620:10d:c0a8:82::c) by ash-exopmbx201.TheFacebook.com (2620:10d:c0a8:83::8) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1713.5; Thu, 31 Oct 2019 08:49:26 -0700 Received: from NAM03-DM3-obe.outbound.protection.outlook.com (100.104.31.183) by o365-in.thefacebook.com (100.104.35.174) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256) id 15.1.1713.5 via Frontend Transport; Thu, 31 Oct 2019 08:49:26 -0700 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=GLJUOcqFUnC5sk32KHRuBHmxs2rpY6JKFjB132p0e7cbH94MbtblzUliSryfgxAnFgBQ+XMxgcuyTXDNEXz5K99K4aZF/JDoObdY8iXIF3SpBSDLozeGSXN3k8VcZAiqdXsIGKKv13CP0wC/8V4ceGImdxkVMNc3e7X6h1pe1ClemzirWGf95kJOEdxElV7FGet09s9Q1kFzfQCWvQ/sBwnWScFmK3rmfAqGbMq8B3RmlO3Hrz3Qfo4jGyxEO7LbR7DWML/CGILoPahnbzXnVUhyfiZnFBDH5FcbhAxY6BlSanN6E6YR+btiKVu372i1cYIfA7BmF6ntTpJXiPPWIQ== 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=ME/H1ACHPe24OMG3vl1RUw07lFiay8ALqV0QNsz8HoE=; b=hp7dZo31EdfpS42NGp9lQu+fGUl8qZLmdObZfcB9yhS2UyNnAyTcViOq8JUjGUf9KaOw6h+l6upuAuqrgjB7m5DxBBq3hZZ0bCGanGGoXT4DXpvLcJLbkC3Nwv8x6THjljWz20oU0LU9F0W2eACoqboKcysOWoLX/BP89DudXNmqZ+EXTkpjPhjDVNmoRdcKf1xr9P6p03futyff8TB6zGNyAsU+xajUOA+yOk3D9NMQw1qGAaYhVCJbrJfxmzuVsdoYYOAcPPP23QwqBxjInmSgcTKg9BZHEBGPbBWNbmQyWfWU9RuIKhks/N9yIDcXO/yW5bgcSymQnETkE5dJMg== 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=ME/H1ACHPe24OMG3vl1RUw07lFiay8ALqV0QNsz8HoE=; b=kB9jWepP2Cb6QNL/59lTb84Xof4u6/kgpjwSm4gRqU6P4eRL0oY0aUZUkL2X0Z50b6ME/5WGxWMhPNg6nAmj4YjbGMLgnUshzxIhXsBHnKtY4qMDG1qUwwBRqyBfXkICszDl+wybchmkaN5DgYZZZ5m2ES9BXKaAKPzZ/+nMBOA= Received: from BN8PR15MB2626.namprd15.prod.outlook.com (20.179.137.220) by BN8PR15MB2836.namprd15.prod.outlook.com (20.178.220.225) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.2387.23; Thu, 31 Oct 2019 15:49:22 +0000 Received: from BN8PR15MB2626.namprd15.prod.outlook.com ([fe80::3056:945b:e60e:e2e0]) by BN8PR15MB2626.namprd15.prod.outlook.com ([fe80::3056:945b:e60e:e2e0%6]) with mapi id 15.20.2387.027; Thu, 31 Oct 2019 15:49:22 +0000 From: Roman Gushchin To: Naoya Horiguchi CC: Andrew Morton , "linux-mm@kvack.org" , Michal Hocko , Johannes Weiner , "linux-kernel@vger.kernel.org" , Kernel Team , "Vladimir Davydov" , Daniel Jordan Subject: Re: [PATCH v2] mm: slab: make page_cgroup_ino() to recognize non-compound slab pages properly Thread-Topic: [PATCH v2] mm: slab: make page_cgroup_ino() to recognize non-compound slab pages properly Thread-Index: AQHVj4mh+jLaqEXqpUiu7sTYH2ejead0JMMAgABaHgCAAGeNAA== Date: Thu, 31 Oct 2019 15:49:22 +0000 Message-ID: <20191031154918.GB31765@tower.DHCP.thefacebook.com> References: <20191031012151.2722280-1-guro@fb.com> <20191030211608.29f8fc92e07fd2ac2ef4d1d3@linux-foundation.org> <20191031093840.GA9178@hori.linux.bs1.fc.nec.co.jp> In-Reply-To: <20191031093840.GA9178@hori.linux.bs1.fc.nec.co.jp> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-clientproxiedby: MWHPR0201CA0070.namprd02.prod.outlook.com (2603:10b6:301:73::47) To BN8PR15MB2626.namprd15.prod.outlook.com (2603:10b6:408:c7::28) x-ms-exchange-messagesentrepresentingtype: 1 x-originating-ip: [2620:10d:c090:200::3:b4b3] x-ms-publictraffictype: Email x-ms-office365-filtering-correlation-id: aaf7965c-3a06-4990-353b-08d75e19e639 x-ms-traffictypediagnostic: BN8PR15MB2836: x-ms-exchange-transport-forked: True x-microsoft-antispam-prvs: x-ms-oob-tlc-oobclassifiers: OLM:8882; x-forefront-prvs: 02070414A1 x-forefront-antispam-report: SFV:NSPM;SFS:(10019020)(39860400002)(376002)(346002)(396003)(366004)(136003)(199004)(189003)(66946007)(66556008)(8936002)(86362001)(81156014)(486006)(11346002)(8676002)(6116002)(1076003)(66446008)(52116002)(476003)(66476007)(99286004)(14454004)(64756008)(81166006)(4326008)(6246003)(446003)(316002)(76176011)(386003)(186003)(6436002)(478600001)(71200400001)(6506007)(256004)(54906003)(71190400001)(14444005)(46003)(229853002)(5660300002)(102836004)(25786009)(6512007)(9686003)(7736002)(33656002)(2906002)(6486002)(305945005)(6916009);DIR:OUT;SFP:1102;SCL:1;SRVR:BN8PR15MB2836;H:BN8PR15MB2626.namprd15.prod.outlook.com;FPR:;SPF:None;LANG:en;PTR:InfoNoRecords;A:1;MX:1; received-spf: None (protection.outlook.com: fb.com does not designate permitted sender hosts) x-ms-exchange-senderadcheck: 1 x-microsoft-antispam: BCL:0; x-microsoft-antispam-message-info: X3j4kLQw3rVNiYOr+Dhcp6K49goKoeWsAyuGeDFqXAc5Sonaw3qiOyL0bsTnpHVWDFAKgocKAZlkdxGUGV/v1mzKYbjVbeKL6eYjX7KZLAwVfbp1JXffb2Kpp1viJ/PMw84ybtR8LbVlTHfKwSTCnBcHJYF75+CfnQAt/zL7kRDY9nhtdHTApoMrSTHu8f8Voc9mIadhKuP/ii7I0WmeJPEQvzDxx+xVVHli88Ul/RRTHkJBB42X06Erb3Z/Zk1nzCauC4VcozSp+o69E7cVyinc6CIg4ACW5Td2Xap9lB3X+tSX9bCrMFyxpFcsHtKnHsxklm7O9EzUoC8hjE+qn8J/gVSdTPwbFPYHCGxFk9WyaK5C18C1AVQQZMppMyCsOXyJCK2TJai+0QZYVOfrjzfbDkE5qGwULrVXmVnbGBpaXQUqIEITVxf+W4S5QFOT Content-Type: text/plain; charset="us-ascii" Content-ID: <93BE932408AEDF4AB353BB35E5BE1331@namprd15.prod.outlook.com> Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-MS-Exchange-CrossTenant-Network-Message-Id: aaf7965c-3a06-4990-353b-08d75e19e639 X-MS-Exchange-CrossTenant-originalarrivaltime: 31 Oct 2019 15:49:22.8305 (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: XI6BOQWb6RDF11EH01oyKblUifBv87iJ/FafGYPNzp/u0AxvosZQHsLH+ohHlcmy X-MS-Exchange-Transport-CrossTenantHeadersStamped: BN8PR15MB2836 X-OriginatorOrg: fb.com X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.95,1.0.8 definitions=2019-10-31_06:2019-10-30,2019-10-31 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 malwarescore=0 impostorscore=0 adultscore=0 suspectscore=0 phishscore=0 spamscore=0 mlxscore=0 priorityscore=1501 mlxlogscore=999 bulkscore=0 lowpriorityscore=0 clxscore=1011 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-1908290000 definitions=main-1910310159 X-FB-Internal: deliver X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Thu, Oct 31, 2019 at 09:38:40AM +0000, Naoya Horiguchi wrote: > On Wed, Oct 30, 2019 at 09:16:08PM -0700, Andrew Morton wrote: > > On Wed, 30 Oct 2019 18:21:51 -0700 Roman Gushchin wrote: > >=20 > > > page_cgroup_ino() doesn't return a valid memcg pointer for non-compou= nd > > > slab pages, because it depends on PgHead AND PgSlab flags to be set > > > to determine the memory cgroup from the kmem_cache. > > > It's correct for compound pages, but not for generic small pages. Tho= se > > > don't have PgHead set, so it ends up returning zero. > > >=20 > > > Fix this by replacing the condition to PageSlab() && !PageTail(). > > >=20 > > > Before this patch: > > > [root@localhost ~]# ./page-types -c /sys/fs/cgroup/user.slice/user-0.= slice/user@0.service/ | grep slab > > > 0x0000000000000080 38 0 _______S_____________________= ______________ slab > > >=20 > > > After this patch: > > > [root@localhost ~]# ./page-types -c /sys/fs/cgroup/user.slice/user-0.= slice/user@0.service/ | grep slab > > > 0x0000000000000080 147 0 _______S_____________________= ______________ slab > > >=20 > > > Fixes: 4d96ba353075 ("mm: memcg/slab: stop setting page->mem_cgroup p= ointer for slab pages") > > > Signed-off-by: Roman Gushchin > > > Reviewed-by: Shakeel Butt > > > Cc: Vladimir Davydov > > > Cc: Daniel Jordan > >=20 > > Affects /proc/kpagecgroup, but page_cgroup_ino() is also used in the > > memory-failure code - I wonder what effect this bug has there? >=20 > hwpoison_filter_task() uses output of page_cgroup_ino() in order to > filter error injection events based on memcg. > So if page_cgroup_ino() fails to return memcg pointer, we just fail > to inject memory error. Considering that hwpoison filter is for testing, > affected users are limited and the impact should be marginal. >=20 > >=20 > > IOW, should we backport this into -stable? >=20 > I think yes, because the patch is small enough and clearly fixes a bug. I agree. Thanks!