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,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,MAILING_LIST_MULTI,PDS_BAD_THREAD_QP_64,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 BAFB9C433ED for ; Thu, 1 Apr 2021 06:20:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 73CBC61055 for ; Thu, 1 Apr 2021 06:20:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233374AbhDAGTp (ORCPT ); Thu, 1 Apr 2021 02:19:45 -0400 Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:13220 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233255AbhDAGTj (ORCPT ); Thu, 1 Apr 2021 02:19:39 -0400 Received: from pps.filterd (m0109334.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.43/8.16.0.43) with SMTP id 13167ndk015678; Wed, 31 Mar 2021 23:19:23 -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=UIniQkwKJg+jl/9UdVNK5ca+xuUBTkZGQqaZUBWIdGg=; b=Bpq+RYA1goMGpRCD8qO2Ld7/s9NqVKqufLAqM6e1pBksAAGRJ/Wr/vGi2/BZrQdNJxue 6Sd8SvkdFD0MajYD4D2LWaPD7oPzvKyroVsyTBpoPQ9wFR9VkFXtJrkfPPrHGM19BuZB rBNDXwTebqtApufl3OyzI6CorI8IQqqdGig= Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com with ESMTP id 37n2a21njr-2 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT); Wed, 31 Mar 2021 23:19:23 -0700 Received: from NAM12-DM6-obe.outbound.protection.outlook.com (100.104.31.183) by o365-in.thefacebook.com (100.104.35.173) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Wed, 31 Mar 2021 23:19:21 -0700 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=VfDBVSmIfUfsACGAeXdXwvM3nQ2vbCIVimBGZLyH8pMIo7yq61F/GL35XCQ1NYQiHyWdv3XbGpW0o4cPrjlaURhZ3Muj/6OT3Kw6uoH+X70vZ/UoLX6vAlrE7LxrF+BDVem+yrGxoA+zCkb/GHjAJwWrmDJK1r+iEwf36/a+aGtwBynj61U+D+fR6yT0hgH47IlYbcS6Iw0q4ems7HEshDG7DNblzQ/BQI57/Ucezqh/KECMOr21tR7W96rMpqRmdONyzhwHMAt1TdsbRpyhTjHb+cVC9SYQkmY+WakmiQkW/9aygLgm+4nvYBuJl4aJWHDVm99afreqX5pbPv5CQA== 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=UIniQkwKJg+jl/9UdVNK5ca+xuUBTkZGQqaZUBWIdGg=; b=AC1+1l3o+DTUm8EBC7Fgqhc1BWtznFQT4p3yulnJTl8vMSyXakdXQdOAa0hRkfjJXGIE+oRC+vX78kDoL8w5nanOWXrckEGrSCXmvDVH+JVHVQTsWaApmBTjafnGBhgMNaTn+iNiHR71kErgHcxTstEcGJcj/52YxLqL7IYzKSfeFOksl0wU3YHBBHKn/aiA9jZKIyerSaFSUEkMBBwa/WaqNQyFjzqs7+xZMKyc1kk32dKuifMCpSGkqcq+eeIoRtJWQOab23NOJQQ4Q7/8Eri+X1mar+s+UUJITLGlh75eZyMt3DGX3byj4HeSO6kZm2mwausKfhXBG5lLqq4a9Q== 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 Received: from BYAPR15MB2999.namprd15.prod.outlook.com (2603:10b6:a03:fa::12) by SJ0PR15MB4567.namprd15.prod.outlook.com (2603:10b6:a03:378::19) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.3977.25; Thu, 1 Apr 2021 06:19:19 +0000 Received: from BYAPR15MB2999.namprd15.prod.outlook.com ([fe80::1ce0:8b27:f740:6b60]) by BYAPR15MB2999.namprd15.prod.outlook.com ([fe80::1ce0:8b27:f740:6b60%4]) with mapi id 15.20.3933.039; Thu, 1 Apr 2021 06:19:19 +0000 From: Song Liu To: Namhyung Kim CC: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Jiri Olsa , Mark Rutland , Alexander Shishkin , LKML , Stephane Eranian , Andi Kleen , "Ian Rogers" , Tejun Heo Subject: Re: [PATCH 1/2] perf/core: Share an event with multiple cgroups Thread-Topic: [PATCH 1/2] perf/core: Share an event with multiple cgroups Thread-Index: AQHXIACsCyQjF284/Uq+advPGrds7aqZrFQAgAEyVQCAAT52gIAAkMUAgAKP/wA= Date: Thu, 1 Apr 2021 06:19:19 +0000 Message-ID: <8C7049AE-A3B8-48C2-8A4B-FB5CADE95F6B@fb.com> References: <20210323162156.1340260-1-namhyung@kernel.org> <20210323162156.1340260-2-namhyung@kernel.org> <180E871A-7C5E-4DB2-80F4-643237A7FA69@fb.com> <8B2062CE-9BD5-4F17-B831-38C9274A1509@fb.com> In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-mailer: Apple Mail (2.3654.60.0.2.21) authentication-results: kernel.org; dkim=none (message not signed) header.d=none;kernel.org; dmarc=none action=none header.from=fb.com; x-originating-ip: [2620:10d:c090:400::5:7a9f] x-ms-publictraffictype: Email x-ms-office365-filtering-correlation-id: 530b4e93-13ab-40cd-cdfa-08d8f4d61585 x-ms-traffictypediagnostic: SJ0PR15MB4567: x-microsoft-antispam-prvs: x-fb-source: Internal x-ms-oob-tlc-oobclassifiers: OLM:9508; x-ms-exchange-senderadcheck: 1 x-microsoft-antispam: BCL:0; x-microsoft-antispam-message-info: 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 x-forefront-antispam-report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:BYAPR15MB2999.namprd15.prod.outlook.com;PTR:;CAT:NONE;SFS:(346002)(376002)(366004)(396003)(39860400002)(136003)(66446008)(66556008)(66476007)(6512007)(2616005)(6506007)(38100700001)(8676002)(64756008)(54906003)(2906002)(33656002)(6486002)(4326008)(76116006)(66946007)(186003)(6916009)(8936002)(86362001)(316002)(83380400001)(478600001)(7416002)(5660300002)(53546011)(71200400001)(36756003)(45980500001);DIR:OUT;SFP:1102; x-ms-exchange-antispam-messagedata: =?us-ascii?Q?DGvUWHvYR2wana0ZF+GwpbDoeNLROnUJp6/CzerpC6Nk+SIdCepuh9msF9VJ?= =?us-ascii?Q?6EqbO4kfmUuRRyj/aClPzoeuL069YYbcViBHWkFQ8DAkjPpxdP9BC//FJjRP?= =?us-ascii?Q?es7H5pE0D3ufBlLGZrdYc9dJhTUcNcHbYFvebmGhgzpoj1vb9O1TAHU53t+S?= =?us-ascii?Q?kYNC9lpVwLmi7tZq7i2rW4u29mZ/jObDqeM9voGwM/IaXKldkrUMCW+yTcAl?= =?us-ascii?Q?cQXGrAkBR9c/sG63pDdUVxl6NE51gYUehCiMNbPL+XykPbWtjfv2AQJ58TzJ?= =?us-ascii?Q?UdEvi6E9NiYZUwzG4hOfOpg4Hvuo1afJreF7O1gb4/LYSdDSGTG+/sqRwlUF?= =?us-ascii?Q?uszDKBEuTK+3eQ8jdyRiToThHfP7BtKWzOQ0Qok1IR82mQSa+1H6NvYLqGQT?= =?us-ascii?Q?W7UNIb+Ommyfz6paph7OJrbIqx4huNFdIplSGovNWviGOAOGSnMOm1dNmxEi?= =?us-ascii?Q?I2mqrMPNQzZUIiP//JAu3l/OOZwIz8MfMYF9W2E7hmMYTaPq6i5ruXgT/SG0?= =?us-ascii?Q?Svh8Tr1iR6aa/jbL4K/DfeZ9wcJktj/PvZ4Z/zZhSTxhO4mduvnBmd3fffgg?= =?us-ascii?Q?Ow1K7Ob4bU2wr97sYY0FrMxT4D4Rn7CXIqa9Dcwy1AqtLbrwbUTO15QxF2Wz?= =?us-ascii?Q?PgNvyvAHP1ZNnBiJKSjua7EnALBvDv1+v6JLiHv82QWOkStaQFk/TNcMJ5Qz?= =?us-ascii?Q?rALJQEOAAo/DXB8bfENwt5wR51U5bv+rKhiDBj+Dkug1wBbYkfOtP1QVsiLt?= =?us-ascii?Q?EWLkZTiirI208yGO9Z17uFKHOsMVAgC9Hx71r9OecNJKUGCqXwKdJ9l9L6O6?= =?us-ascii?Q?Cr6NqYzu3TMG07yFXf1Yw6h5zDWV/0qalZYcfBY9ZKxu0JInkClRhntlsSrk?= =?us-ascii?Q?DNdgBhru+6IifdAvTU7yc3Yvdi4puVzEYQrbw4n7VwJ4JqsCCprx3oQyjQAg?= =?us-ascii?Q?Q+KHmMIboNMpYfJFgxbL/G5JOV1FQ/kmhHqk42wKl6Es9rmWF+2efG/c22Cz?= =?us-ascii?Q?znHRvAMexR7bML8G5vHn1q2Fn0oFtiSQDXpSJ4v6x+I34VyxQkCc4voNPRZt?= =?us-ascii?Q?MKKSjDKtOXG6OnAcSixXJ/4JLMUWGAcb4po/kXxQcCzwefY0Q6CaNWVRXjtY?= =?us-ascii?Q?m92fHHFOyBXINMkjQrdCHaiPabGJz1P+FdYz+ib+um2G0gHYR0+/Hjd+w21M?= =?us-ascii?Q?DPD1Z3VE5nvt93WSNMDeQ/vI2dHWMPAFm5L1XhnLl5J0BBkYlatm5AXwftf8?= =?us-ascii?Q?y6hrO/iIFB/qYBTSFjex7QLniW05k+OUKt7xBhrEjeKJ4bmnITQ3HfU1E3Ic?= =?us-ascii?Q?wiSUhZr4ccNnIzbhfhk4DCAr/0had8tKv9l1186D/81JA6+JsBsNTpMeGZhV?= =?us-ascii?Q?nbnVe+w=3D?= x-ms-exchange-transport-forked: True Content-Type: text/plain; charset="us-ascii" Content-ID: <0903B50F31534B47984A4B85580D50F8@namprd15.prod.outlook.com> Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-AuthSource: BYAPR15MB2999.namprd15.prod.outlook.com X-MS-Exchange-CrossTenant-Network-Message-Id: 530b4e93-13ab-40cd-cdfa-08d8f4d61585 X-MS-Exchange-CrossTenant-originalarrivaltime: 01 Apr 2021 06:19:19.2985 (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: cntDG6x0OFkKlhWiS6clZs+1GNWAuhuKJG1cl0DX49CxwnD2DrGk7Yb78pbaGbhRJRMspVE5fsL+6qjRgY/jMg== X-MS-Exchange-Transport-CrossTenantHeadersStamped: SJ0PR15MB4567 X-OriginatorOrg: fb.com X-Proofpoint-GUID: R8OjVmpom6L90ZS5UN_WtCpyacWbKgG4 X-Proofpoint-ORIG-GUID: R8OjVmpom6L90ZS5UN_WtCpyacWbKgG4 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.369,18.0.761 definitions=2021-04-01_02:2021-03-31,2021-04-01 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 impostorscore=0 mlxscore=0 priorityscore=1501 spamscore=0 clxscore=1015 bulkscore=0 suspectscore=0 adultscore=0 phishscore=0 malwarescore=0 mlxlogscore=999 lowpriorityscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2103310000 definitions=main-2104010045 X-FB-Internal: deliver Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > On Mar 30, 2021, at 8:11 AM, Namhyung Kim wrote: >=20 > On Tue, Mar 30, 2021 at 3:33 PM Song Liu wrote: >>> On Mar 29, 2021, at 4:33 AM, Namhyung Kim wrote: >>>=20 >>> On Mon, Mar 29, 2021 at 2:17 AM Song Liu wrote: >>>>> On Mar 23, 2021, at 9:21 AM, Namhyung Kim wrote= : >>>>>=20 >>>>> As we can run many jobs (in container) on a big machine, we want to >>>>> measure each job's performance during the run. To do that, the >>>>> perf_event can be associated to a cgroup to measure it only. >>>>>=20 >>=20 >> [...] >>=20 >>>>> + return 0; >>>>> +} >>>>=20 >>>> Could you please explain why we need this logic in can_attach? >>>=20 >>> IIUC the ss->attach() is called after a task's cgroup membership >>> is changed. But we want to collect the performance numbers for >>> the old cgroup just before the change. As the logic merely checks >>> the current task's cgroup, it should be done in the can_attach() >>> which is called before the cgroup change. >>=20 >> Thanks for the explanations. >>=20 >> Overall, I really like the core idea, especially that the overhead on >> context switch is bounded (by the depth of cgroup tree). >=20 > Thanks! >=20 >>=20 >> Is it possible to make PERF_EVENT_IOC_ATTACH_CGROUP more flexible? >> Specifically, if we can have >>=20 >> PERF_EVENT_IOC_ADD_CGROUP add a cgroup to the list >> PERF_EVENT_IOC_EL_CGROUP delete a cgroup from the list >>=20 >> we can probably share these events among multiple processes, and >> these processes don't need to know others' cgroup list. I think >> this will be useful for users to build customized monitoring in >> its own container. >>=20 >> Does this make sense? >=20 > Maybe we can add ADD/DEL interface for more flexible monitoring > but I'm not sure which use cases it'll be used actually. >=20 > For your multi-process sharing case, the original events' file > descriptors should be shared first. =20 Yes, we will need some other work to make the ADD/DEL interface=20 work properly. Let's worry about that later.=20 For both patches: Acked-by: Song Liu Thanks, Song [...]