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=-4.2 required=3.0 tests=DKIMWL_WL_HIGH,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS 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 7BA87C282D7 for ; Wed, 30 Jan 2019 21:12:45 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 1371E218AF for ; Wed, 30 Jan 2019 21:12:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=fb.com header.i=@fb.com header.b="j7RFVe1Y"; dkim=pass (1024-bit key) header.d=fb.onmicrosoft.com header.i=@fb.onmicrosoft.com header.b="KaopT+1M" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1371E218AF 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 B134E8E0002; Wed, 30 Jan 2019 16:12:44 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id A9D2E8E0001; Wed, 30 Jan 2019 16:12:44 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 93CD08E0002; Wed, 30 Jan 2019 16:12:44 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from mail-yb1-f198.google.com (mail-yb1-f198.google.com [209.85.219.198]) by kanga.kvack.org (Postfix) with ESMTP id 688B08E0001 for ; Wed, 30 Jan 2019 16:12:44 -0500 (EST) Received: by mail-yb1-f198.google.com with SMTP id u17so492012ybk.20 for ; Wed, 30 Jan 2019 13:12:44 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:dkim-signature:dkim-signature:from:to:cc:subject :thread-topic:thread-index:date:message-id:references:in-reply-to :accept-language:content-language:content-id :content-transfer-encoding:mime-version; bh=tH/IbfNKhRC6ZrYi91YP5b3b99YaZHESbAqbffdYLP0=; b=kce3rQc7m3WVth93jjWYjVTUjeZv0yEL6uSdvKMz3feNgPF3YreHb9Ep7gw/O186F4 wV0uCL2dLhQXylP4eMcLjI4+9DiJqpfQvQellRuF5pFRC5OOsRKVrOxPDk9MzLQ0wWGA EjJ01mfoFilKE477GkD6i22TcOJk2YkASuhpyw+JW2sYGSCX9GZvFShtVktNwpsbnq/X FxdtFZVgV1J2d+hLVz2gqpdfXhEhTuOogDjQ+0M2F3UYxVTc/dLOTN9nPA2DJFUEY0Xo fujBwaZvPAsgQEwmCzpL7LweDC5IvII9mhOKRZeax3yRpyPf/9ZsMIw40C571crrJv1W CG8A== X-Gm-Message-State: AHQUAubBinO2BE1vkFcmMrRXO2ns1fwyQyvQolnKPs16icXbuKZKoJSV pBzLQmIVZLLFZWKLR62eGtLWJFlKWDiJevWY6IZI2OD6BZF4WBgDYotIdc7BNXOyDsq+uf5lDh6 ap/NAP+gNCKlFjYxMVjZUSoH3bWwbdWSld9vvjGAOj3KRfXK7H5L5/YTNE+pUCmW71w== X-Received: by 2002:a25:30c3:: with SMTP id w186mr19180824ybw.24.1548882763784; Wed, 30 Jan 2019 13:12:43 -0800 (PST) X-Google-Smtp-Source: AHgI3IafsAx+p01QjYHt5upheY3oQ+8O9YBje1cEuet47cCijYQFSSz4+PLUcUwPdh0RQjsWfrzJ X-Received: by 2002:a25:30c3:: with SMTP id w186mr19180786ybw.24.1548882763140; Wed, 30 Jan 2019 13:12:43 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1548882763; cv=none; d=google.com; s=arc-20160816; b=EULV8BAgt7mabX9Vr48w6a98dhQsHkTKo/acBlbJzSqJLy/9sRTzxuAvy4+IucMDI/ 0PahTrHK9whbGbgr3GlMeKGsZEMFXLgTyaNGoM30+fUgekeNAwY4GEjxdSuL49s7brmV 0P2gUCv4PMJ8k4JU81SMERsYm2GhYotKY8f7RNWZBkOZNn0ifnKiBd44bjOp1QHfMdY2 zJfu1aNKLLZgd8d8Omw32kVg7ZMFwjNuEe6T4C2NQVeFbtCvzekzBLgVYwuy8ZuFfowe dgOKuXXjNh64CsciIokNLkZHz1zHB8xlsfzbeQutT3Lll7br38NB8lCy3Y/rxljn+lxo jYow== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:content-transfer-encoding:content-id:content-language :accept-language:in-reply-to:references:message-id:date:thread-index :thread-topic:subject:cc:to:from:dkim-signature:dkim-signature; bh=tH/IbfNKhRC6ZrYi91YP5b3b99YaZHESbAqbffdYLP0=; b=n3ig1ykAgVj/TeT9rdIZS8qVSXgfbnF7rZH+auzbUYJoSCaXoLxo3crsSoGYx6BjFD nL/YCelGmVVvGVCJt6itKKRsqi7G4CJWZxz4QhoIRNa+iOtteUHwSSUlqy7x21pKDzgv oNFC7jFxOCTr/MPaY7of7oAVFXEXOJtWb9+CpEptL3W4Cukh3Y7DuBAK6K8XYE8JNP/S EUG084XtJKB5tR7zwNwsEluS+YsKjY7OfunyA02UnlP89/ycUvhKgmN0wO3HeevzjNJD 4aOkV1v0Ob+9Y8oCghjPNgQ4wFMM0pn+ZfRrFg/Ls6huna6rrQrQ2UdYVztVCRclJhke MFhg== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@fb.com header.s=facebook header.b=j7RFVe1Y; dkim=pass header.i=@fb.onmicrosoft.com header.s=selector1-fb-com header.b=KaopT+1M; spf=pass (google.com: domain of prvs=793397e901=guro@fb.com designates 67.231.145.42 as permitted sender) smtp.mailfrom="prvs=793397e901=guro@fb.com"; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=fb.com Received: from mx0a-00082601.pphosted.com (mx0a-00082601.pphosted.com. [67.231.145.42]) by mx.google.com with ESMTPS id j190si1509054ywd.368.2019.01.30.13.12.42 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 30 Jan 2019 13:12:43 -0800 (PST) Received-SPF: pass (google.com: domain of prvs=793397e901=guro@fb.com designates 67.231.145.42 as permitted sender) client-ip=67.231.145.42; Authentication-Results: mx.google.com; dkim=pass header.i=@fb.com header.s=facebook header.b=j7RFVe1Y; dkim=pass header.i=@fb.onmicrosoft.com header.s=selector1-fb-com header.b=KaopT+1M; spf=pass (google.com: domain of prvs=793397e901=guro@fb.com designates 67.231.145.42 as permitted sender) smtp.mailfrom="prvs=793397e901=guro@fb.com"; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=fb.com Received: from pps.filterd (m0044008.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x0UL9LbQ009030; Wed, 30 Jan 2019 13:12:39 -0800 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=tH/IbfNKhRC6ZrYi91YP5b3b99YaZHESbAqbffdYLP0=; b=j7RFVe1YRRvGgsrFau+tskht5dMEWRpu6r0fQ/lfty+436yrVlEsJlxpoBGqbO+vi3LH 27BqNo+Iv9ZazaJN510Dp3AIg84uh7ioerCpFeCPsM7OU7kkqHSptP/teY6aP6/sveeX w6nT3neR2tJGSoNnPAjkD4EJsMWPlErZG+U= Received: from maileast.thefacebook.com ([199.201.65.23]) by mx0a-00082601.pphosted.com with ESMTP id 2qbkf3r1f1-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-SHA384 bits=256 verify=NOT); Wed, 30 Jan 2019 13:12:39 -0800 Received: from frc-mbx05.TheFacebook.com (2620:10d:c0a1:f82::29) by frc-hub03.TheFacebook.com (2620:10d:c021:18::173) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id 15.1.1531.3; Wed, 30 Jan 2019 13:12:37 -0800 Received: from frc-hub05.TheFacebook.com (2620:10d:c021:18::175) by frc-mbx05.TheFacebook.com (2620:10d:c0a1:f82::29) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id 15.1.1531.3; Wed, 30 Jan 2019 13:12:37 -0800 Received: from NAM03-DM3-obe.outbound.protection.outlook.com (192.168.183.28) by o365-in.thefacebook.com (192.168.177.75) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id 15.1.1531.3 via Frontend Transport; Wed, 30 Jan 2019 13:12:37 -0800 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.onmicrosoft.com; s=selector1-fb-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=tH/IbfNKhRC6ZrYi91YP5b3b99YaZHESbAqbffdYLP0=; b=KaopT+1McO7R//b2r5nPkrPXflGDzGDJtucXHNqWXU1IR4uwzohxZBYYWet5fqTKBhKuSt11NpeuoSdBjPaLsd91l1OD7+4HaiTWbges8c2c7iBijAVkxh1CtLj8zlFIjGeREdnjUp3xQAcLSxxJddhh5cP8+43GECV6zAd5AQE= Received: from BYAPR15MB2631.namprd15.prod.outlook.com (20.179.156.24) by BYAPR15MB2230.namprd15.prod.outlook.com (52.135.196.157) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.1558.17; Wed, 30 Jan 2019 21:12:35 +0000 Received: from BYAPR15MB2631.namprd15.prod.outlook.com ([fe80::ecc7:1a8c:289f:df92]) by BYAPR15MB2631.namprd15.prod.outlook.com ([fe80::ecc7:1a8c:289f:df92%3]) with mapi id 15.20.1580.017; Wed, 30 Jan 2019 21:12:35 +0000 From: Roman Gushchin To: Chris Down CC: Andrew Morton , Johannes Weiner , Michal Hocko , Tejun Heo , Dennis Zhou , "linux-kernel@vger.kernel.org" , "cgroups@vger.kernel.org" , "linux-mm@kvack.org" , Kernel Team Subject: Re: [PATCH v3] mm: Make memory.emin the baseline for utilisation determination Thread-Topic: [PATCH v3] mm: Make memory.emin the baseline for utilisation determination Thread-Index: AQHUuAcB1sKq7eSF7Ue9hhxxElYkPqXIUPYA Date: Wed, 30 Jan 2019 21:12:35 +0000 Message-ID: <20190130211226.GA6216@castle.DHCP.thefacebook.com> References: <20190129182516.GA1834@chrisdown.name> <20190129190253.GA10430@chrisdown.name> <20190129191525.GB10430@chrisdown.name> In-Reply-To: <20190129191525.GB10430@chrisdown.name> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-clientproxiedby: MWHPR1601CA0017.namprd16.prod.outlook.com (2603:10b6:300:da::27) To BYAPR15MB2631.namprd15.prod.outlook.com (2603:10b6:a03:152::24) x-ms-exchange-messagesentrepresentingtype: 1 x-originating-ip: [2620:10d:c090:180::1:1669] x-ms-publictraffictype: Email x-microsoft-exchange-diagnostics: 1;BYAPR15MB2230;20:KCu0Kij4zkirSSPpDAMa1FmCaulPC8bmhz3co3hkp3wLEznaHNCAA+bejy9AoQ0dl21I86w+3daSlROrJ+S7qNNUbMmR+dnYoKmDH78f+MTAb+MDGk7Q2m9cb82I/offnacHGlkaK6HwiWcuXVLS2ziIF7rggFkYkyregTJhFpo= x-ms-office365-filtering-correlation-id: e87b0942-1915-4fbd-e157-08d686f7a820 x-microsoft-antispam: BCL:0;PCL:0;RULEID:(2390118)(7020095)(4652040)(8989299)(4534185)(4627221)(201703031133081)(201702281549075)(8990200)(5600110)(711020)(4605077)(2017052603328)(7153060)(7193020);SRVR:BYAPR15MB2230; x-ms-traffictypediagnostic: BYAPR15MB2230: x-microsoft-antispam-prvs: x-forefront-prvs: 0933E9FD8D x-forefront-antispam-report: SFV:NSPM;SFS:(10019020)(376002)(346002)(396003)(136003)(366004)(39860400002)(189003)(199004)(9686003)(6506007)(76176011)(478600001)(2906002)(71200400001)(6512007)(81166006)(186003)(8676002)(33896004)(33656002)(25786009)(53936002)(81156014)(71190400001)(6916009)(52116002)(97736004)(102836004)(386003)(14454004)(68736007)(446003)(6116002)(105586002)(4326008)(229853002)(8936002)(46003)(86362001)(6436002)(99286004)(6246003)(54906003)(256004)(476003)(11346002)(106356001)(316002)(6486002)(7736002)(486006)(1076003)(305945005)(45673001);DIR:OUT;SFP:1102;SCL:1;SRVR:BYAPR15MB2230;H:BYAPR15MB2631.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: m2d6xh0DOXSSl3ylnm9Tw1Z4dC/jU3iZbSLkvXGFOoXoyqbGsJAFATgTDXkFsGmIYYkeHXPAdESz3gv+wwv2HzqWHcT50VDX8BVqUHzMzwNC9sj/q1g4kz2OGM5XJ0bdetgT3XOwOEgFgVxj7zN440YFQXF2aQ+wc/9oDLUZBfpPYvXQ5LB2x+P2aiVL6/Oz+UlR/d3geSBebymgny0wDAtnGmh0NTq5NRvMFCA7kGJiaHwrYFA6BWxfc0EH+3INwl6hvy8Jnr0pL4gIV4q8hGjCYAT7Vr5AlUiRv/nLDAFengkKzyhz5Kp4aDaVYlQw0lMeKgsLxauQMDLs08JNAxdXQYWGNu44xO1UZDg2DJv3Xh5T7sC7Hj96SuFKI3KnJWozt3X0pH9AN/flfZFmhfOddCooy4mCT0573+2VwTU= Content-Type: text/plain; charset="us-ascii" Content-ID: Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-MS-Exchange-CrossTenant-Network-Message-Id: e87b0942-1915-4fbd-e157-08d686f7a820 X-MS-Exchange-CrossTenant-originalarrivaltime: 30 Jan 2019 21:12:34.4907 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: 8ae927fe-1255-47a7-a2af-5f3a069daaa2 X-MS-Exchange-Transport-CrossTenantHeadersStamped: BYAPR15MB2230 X-OriginatorOrg: fb.com X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-01-30_16:,, signatures=0 X-Proofpoint-Spam-Reason: safe X-FB-Internal: Safe 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 Tue, Jan 29, 2019 at 02:15:25PM -0500, Chris Down wrote: > Roman points out that when when we do the low reclaim pass, we scale the > reclaim pressure relative to position between 0 and the maximum > protection threshold. >=20 > However, if the maximum protection is based on memory.elow, and > memory.emin is above zero, this means we still may get binary behaviour > on second-pass low reclaim. This is because we scale starting at 0, not > starting at memory.emin, and since we don't scan at all below emin, we > end up with cliff behaviour. >=20 > This should be a fairly uncommon case since usually we don't go into the > second pass, but it makes sense to scale our low reclaim pressure > starting at emin. >=20 > You can test this by catting two large sparse files, one in a cgroup > with emin set to some moderate size compared to physical RAM, and > another cgroup without any emin. In both cgroups, set an elow larger > than 50% of physical RAM. The one with emin will have less page > scanning, as reclaim pressure is lower. >=20 > Signed-off-by: Chris Down > Suggested-by: Roman Gushchin > Cc: Johannes Weiner > Cc: Andrew Morton > Cc: Michal Hocko > Cc: Tejun Heo > Cc: Roman Gushchin > Cc: Dennis Zhou > Cc: linux-kernel@vger.kernel.org > Cc: cgroups@vger.kernel.org > Cc: linux-mm@kvack.org > Cc: kernel-team@fb.com Acked-by: Roman Gushchin Thanks!