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=-6.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 749F5C43331 for ; Thu, 5 Sep 2019 22:35:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9CD9D206DE for ; Thu, 5 Sep 2019 22:35:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=fb.com header.i=@fb.com header.b="lgiWG62u"; dkim=pass (1024-bit key) header.d=fb.onmicrosoft.com header.i=@fb.onmicrosoft.com header.b="RfVbn7/U" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390289AbfIEWfE (ORCPT ); Thu, 5 Sep 2019 18:35:04 -0400 Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:60134 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729719AbfIEWfD (ORCPT ); Thu, 5 Sep 2019 18:35:03 -0400 Received: from pps.filterd (m0044012.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id x85MYrsI023475; Thu, 5 Sep 2019 15:34:54 -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=VY471la3L23Eltq2xlADCf9gAVZ6iQBEblPJizEYpEQ=; b=lgiWG62uqE6joB6UswrVyimddV9WAsC/9smtAbz6hCN1/CxiK+QeCzmICKCpJDOfHxOQ 7ExPgBHU/g20E7Xoz7eoO2LbByKAcBwZeVpMBHVrs502hMdSUUJxsfBoQ8xpjnrAIxjq f69ApCr2vOeprzj+ESPqycj8Kpt0Bfy5dSc= Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com with ESMTP id 2uu3nb2b21-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT); Thu, 05 Sep 2019 15:34:54 -0700 Received: from ash-exhub201.TheFacebook.com (2620:10d:c0a8:83::7) by ash-exhub204.TheFacebook.com (2620:10d:c0a8:83::4) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1713.5; Thu, 5 Sep 2019 15:34:39 -0700 Received: from NAM03-DM3-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 15.1.1713.5 via Frontend Transport; Thu, 5 Sep 2019 15:34:39 -0700 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=Rt2YPxKlVRFGeKkC07UZ3HXKdabTIRgE6MYwC+JKPjT9yqQbAYxDi7V6CDGoL3wzBHcPQxRtlv6zVOV7ZQfWZtphtUV9jvTiKFcx9X07miLklgdN/3mC4HicoH8Xd4TeyLPxG/GMsab2/6dPnogPh0GOpjC7rC+OG9A5qSeSnCP51MGfSNJXXkELsrd7ZMTtBumh010ISchoqvysFl7lVN+0o8qcYleUSOgpgwcWY4CCh62naWj81xkLOA4ntGFB1usLiF6bQsQFhHtIJ17HODM+t25RYfo/Plw34tNjH/Naf4TO+9OWP3qh0XqPQqz07knfeoTDIh8eqrMUgCPzgg== 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=VY471la3L23Eltq2xlADCf9gAVZ6iQBEblPJizEYpEQ=; b=HnXrnmZJuWx8nRLarRanoq5GhScdID6gJ78UFfurxExEsv5KKAU6G8rtvL3eDBU+dNeDwU2RpmPMmRaoiiQ3w/JPzntjDEjH3pb3DD/UT7gc0p7G+7d1P4tBL3hCEnWbNal3JOZLlwHUMwroR8pGqGUEQjb1aZcqP9/WbFNYkhY1BYocKfx+l7/VFCb+ONzeR4sAvNwytlcuXPz/qmqBtON+Eiec/2qXSWmtvR1hFPJHXE0t6SgcxETyLNab1XDMGVpfVaahOyphXSGCEwfpdiGoHy3scWI0oLlOHJYcCcaTLh3oM9WpyCvbjSlWIv9QNQ/3RIW7eqKJ6io6H9biFQ== 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=VY471la3L23Eltq2xlADCf9gAVZ6iQBEblPJizEYpEQ=; b=RfVbn7/UpD03INfd0lqblzOwN93JfP2IYmApfnJz/RTfk4DoWLEakcHZbK3xyzkq1xEVZBSzokpTOgnmDhP+xtYXNbtGnbPWuPPoE8Cvw8D6TuOFN0q69NvCEC1XoffQEqa4fDXD739G68He123EZcWQVAXVuuoTLhDgmvNBkXc= Received: from DM6PR15MB2635.namprd15.prod.outlook.com (20.179.161.152) by DM6PR15MB2588.namprd15.prod.outlook.com (20.179.161.13) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.2220.19; Thu, 5 Sep 2019 22:34:37 +0000 Received: from DM6PR15MB2635.namprd15.prod.outlook.com ([fe80::d1fc:b5c5:59a1:bd7e]) by DM6PR15MB2635.namprd15.prod.outlook.com ([fe80::d1fc:b5c5:59a1:bd7e%3]) with mapi id 15.20.2220.022; Thu, 5 Sep 2019 22:34:37 +0000 From: Roman Gushchin To: "linux-mm@kvack.org" CC: Michal Hocko , Johannes Weiner , "linux-kernel@vger.kernel.org" , Kernel Team , Shakeel Butt , Vladimir Davydov , Waiman Long Subject: Re: [PATCH RFC 02/14] mm: memcg: introduce mem_cgroup_ptr Thread-Topic: [PATCH RFC 02/14] mm: memcg: introduce mem_cgroup_ptr Thread-Index: AQHVZDNrTEPuqgxSak+O+uxAJpftMqcdq8aA Date: Thu, 5 Sep 2019 22:34:37 +0000 Message-ID: <20190905223433.GA5686@tower.DHCP.thefacebook.com> References: <20190905214553.1643060-1-guro@fb.com> <20190905214553.1643060-3-guro@fb.com> In-Reply-To: <20190905214553.1643060-3-guro@fb.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-clientproxiedby: BYAPR03CA0031.namprd03.prod.outlook.com (2603:10b6:a02:a8::44) To DM6PR15MB2635.namprd15.prod.outlook.com (2603:10b6:5:1a6::24) x-ms-exchange-messagesentrepresentingtype: 1 x-originating-ip: [2620:10d:c090:200::2:3ae5] x-ms-publictraffictype: Email x-ms-office365-filtering-correlation-id: 5b2a305e-9719-4004-a1c5-08d732513bcc x-microsoft-antispam: BCL:0;PCL:0;RULEID:(2390118)(7020095)(4652040)(8989299)(4534185)(4627221)(201703031133081)(201702281549075)(8990200)(5600166)(711020)(4605104)(1401327)(2017052603328)(7193020);SRVR:DM6PR15MB2588; x-ms-traffictypediagnostic: DM6PR15MB2588: x-ms-exchange-transport-forked: True x-microsoft-antispam-prvs: x-ms-oob-tlc-oobclassifiers: OLM:2276; x-forefront-prvs: 015114592F x-forefront-antispam-report: SFV:NSPM;SFS:(10019020)(396003)(346002)(39860400002)(376002)(136003)(366004)(189003)(199004)(66446008)(6916009)(66946007)(99286004)(229853002)(66556008)(2351001)(478600001)(66476007)(2501003)(4326008)(8676002)(305945005)(102836004)(53936002)(14454004)(256004)(8936002)(81166006)(64756008)(46003)(386003)(6506007)(186003)(14444005)(7736002)(6116002)(2906002)(1076003)(6246003)(54906003)(316002)(52116002)(76176011)(446003)(9686003)(6512007)(86362001)(71200400001)(71190400001)(6486002)(25786009)(476003)(5640700003)(33656002)(5660300002)(11346002)(486006)(6436002)(81156014);DIR:OUT;SFP:1102;SCL:1;SRVR:DM6PR15MB2588;H:DM6PR15MB2635.namprd15.prod.outlook.com;FPR:;SPF:None;LANG:en;PTR:InfoNoRecords;MX:1;A:1; received-spf: None (protection.outlook.com: fb.com does not designate permitted sender hosts) x-ms-exchange-senderadcheck: 1 x-microsoft-antispam-message-info: Ks7oYVBbmpox29+muoDTynV9N3+/wryPzrfHrpYkripb1/fncqgPjFYyUfoEZsBNHn2hmHxusu2PSIYeFyJQfNxv8SJ9pJAUUouZYFa9PQ01f3hRjS2IZOX5lFaMZaQtOzVe6OlT2aeC0grENyStFPH0UPitU1+nGxgXPhX0NN0bsDc9Ffhf1QVloIVgX0Fdla9yHq0/bMwZuFxuOJblataa4gH+FdCD474DFbEzvsSssrj7TIdJTFxuebNuXozutKzpn91kNiKpHkmRv8vmNDTMyx7JvQ8bKCD5ADRFCkimh0MMuazBcYacmHFqvywFd7ssWm2P56rMxxCqrS8kQ7EITY2WEWpvPQsa3Mh/rTUyjfzpqLAvlUJFpUCxcMlmtR1l2MjcvfhUB4Yz+LsMk5Snk6ANs5mm1xIx7xY3nWc= Content-Type: text/plain; charset="us-ascii" Content-ID: <6463A4F811D7454BAA30EB4757C0A3E7@namprd15.prod.outlook.com> Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-MS-Exchange-CrossTenant-Network-Message-Id: 5b2a305e-9719-4004-a1c5-08d732513bcc X-MS-Exchange-CrossTenant-originalarrivaltime: 05 Sep 2019 22:34:37.5289 (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: W8HnaHiOgtPM0envqFx0M9aB8GS5Daw2c1gVEWxNSPGn0zvlCN/JjNE+iytWorX+ X-MS-Exchange-Transport-CrossTenantHeadersStamped: DM6PR15MB2588 X-OriginatorOrg: fb.com X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.70,1.0.8 definitions=2019-09-05_09:2019-09-04,2019-09-05 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 clxscore=1015 spamscore=0 lowpriorityscore=0 mlxscore=0 malwarescore=0 bulkscore=0 adultscore=0 mlxlogscore=964 priorityscore=1501 suspectscore=0 impostorscore=0 phishscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-1906280000 definitions=main-1909050210 X-FB-Internal: deliver Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Sep 05, 2019 at 02:45:46PM -0700, Roman Gushchin wrote: > This commit introduces mem_cgroup_ptr structure and corresponding API. > It implements a pointer to a memory cgroup with a built-in reference > counter. The main goal of it is to implement reparenting efficiently. >=20 > If a number of objects (e.g. slab pages) have to keep a pointer and > a reference to a memory cgroup, they can use mem_cgroup_ptr instead. > On reparenting, only one mem_cgroup_ptr->memcg pointer has to be > changed, instead of walking over all accounted objects. >=20 > mem_cgroup_ptr holds a single reference to the corresponding memory > cgroup. Because it's initialized before the css reference counter, > css's refcounter can't be bumped at allocation time. Instead, it's > bumped on reparenting which happens during offlining. A cgroup is > never released online, so it's fine. >=20 > mem_cgroup_ptr is released using rcu, so memcg->kmem_memcg_ptr can > be accessed in a rcu read section. On reparenting it's atomically > switched to NULL. If the reader gets NULL, it can just read parent's > kmem_memcg_ptr instead. >=20 > Each memory cgroup contains a list of kmem_memcg_ptrs. On reparenting > the list is spliced into the parent's list. The list is protected > using the css set lock. >=20 > Signed-off-by: Roman Gushchin > --- > include/linux/memcontrol.h | 50 ++++++++++++++++++++++ > mm/memcontrol.c | 87 ++++++++++++++++++++++++++++++++++++-- > 2 files changed, 133 insertions(+), 4 deletions(-) >=20 > diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h > index 120d39066148..dd5ebfe5a86c 100644 > --- a/include/linux/memcontrol.h > +++ b/include/linux/memcontrol.h > @@ -23,6 +23,7 @@ > #include > =20 > struct mem_cgroup; > +struct mem_cgroup_ptr; > struct page; > struct mm_struct; > struct kmem_cache; > @@ -197,6 +198,22 @@ struct memcg_cgwb_frn { > int memcg_id; /* memcg->css.id of foreign inode */ > u64 at; /* jiffies_64 at the time of dirtying */ > struct wb_completion done; /* tracks in-flight foreign writebacks */ > +} Oops, a semicolon has been lost during the final rebase. I'll send a correct version of this patch separately. Sorry for the mess.