Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753142AbdHKPI1 (ORCPT ); Fri, 11 Aug 2017 11:08:27 -0400 Received: from mail-ve1eur01on0082.outbound.protection.outlook.com ([104.47.1.82]:15520 "EHLO EUR01-VE1-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752823AbdHKPIZ (ORCPT ); Fri, 11 Aug 2017 11:08:25 -0400 Authentication-Results: spf=none (sender IP is ) smtp.mailfrom=cmetcalf@mellanox.com; Subject: Re: [RFC PATCH 0/9] Introduce housekeeping subsystem To: Mike Galbraith , Frederic Weisbecker Cc: LKML , Peter Zijlstra , Thomas Gleixner , Luiz Capitulino , Christoph Lameter , "Paul E . McKenney" , Ingo Molnar , Rik van Riel , Wanpeng Li References: <1500643290-25842-1-git-send-email-fweisbec@gmail.com> <20170810125437.GA8754@lerouge> <3398d7d6-74c2-4918-ae3d-aa5a2e3a12dd@mellanox.com> <1502433388.16425.9.camel@gmx.de> From: Chris Metcalf Message-ID: <3ff0c384-dcd9-41e5-c7cc-43c856a4a51e@mellanox.com> Date: Fri, 11 Aug 2017 11:08:09 -0400 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.2.1 MIME-Version: 1.0 In-Reply-To: <1502433388.16425.9.camel@gmx.de> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US X-Originating-IP: [69.156.215.138] X-ClientProxiedBy: BN6PR09CA0069.namprd09.prod.outlook.com (2603:10b6:404:7a::31) To DB6PR0501MB2759.eurprd05.prod.outlook.com (2603:10a6:4:82::11) X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: 45e90c9a-2264-48d1-9f3b-08d4e0cacdab X-MS-Office365-Filtering-HT: Tenant X-Microsoft-Antispam: UriScan:;BCL:0;PCL:0;RULEID:(300000500095)(300135000095)(300000501095)(300135300095)(22001)(300000502095)(300135100095)(2017030254152)(300000503095)(300135400095)(48565401081)(201703131423075)(201703031133081)(201702281549075)(300000504095)(300135200095)(300000505095)(300135600095)(300000506095)(300135500095);SRVR:DB6PR0501MB2759; X-Microsoft-Exchange-Diagnostics: 1;DB6PR0501MB2759;3:B5FDGVzQ2M6vQsAcx/tXhfpIUzsjWokH6PVklZCWLcBP44IoC09YeLpba7kCRgf5ephDjvg9vsYFXvIZwy2qjoMJ3v8Syy64apAlD1vEUu4461RU44weG17SaD3mvxRpqRQ3sOOzT/14nnco8J62i7T19t3Yo9DMZBeQ7qtXOuDjku8uo1fQ95BXpleC2ve0Zj4/tVcMDvIVCbCkv5cVzW5lmJ7XbjhZTPpiKn8EOmwuSaerYn4lxG50kqduu/eZ;25:JUBmiL8+5HX082WavwwxVBUD6xYgf+wgq4BxVtsntNQzL82t2x/oG/Mzv2lXMiJ6KBwR3uqJ9freO2alrB9bNLCBMpVfj3LW0/xGWKv6m3B+mXMaWznFxIcWRiR1yQmPR2qgtlyXU1F0OldwL+v0InK163Gs9RO9muyElulkAFSXsqSrr321OXOWFzXGP/lqkMoijNOaXGuAtqE5eaPUCMIRRCRRPFVu3VU4QOgZf5eEoyAhMCh5DzRbmI24oouovWond5Ww91fZXgq2/tkpvfQBzkujJ+EvbX+6UN31RhwB1Am4JS1VJ1diuUlj/ckezNkvaGmJkgf6rtTmAXNFlA==;31:HV7eJ1zwxlkaRcoNr6gIXFVK3DEj4kKhoAsWcwSQ/MohqzjbHE6pmcupDM4hyrIK0eX35dh8yw+4+j9IcnU/p1wN9kYM8Z9AY9uAV6oK/k15+a2lIDW4RE0BK3eIDvXKw++gs99kcQ8nY7UnXfb1ObNYvZWjw61gC2XvoPbDI57+JXCt6/h5mwk4C1s5w5whkaBlOiAtJvEIJqNdWytqOtVfw3hV1qcMmhHXV1zBnEc= X-MS-TrafficTypeDiagnostic: DB6PR0501MB2759: X-Microsoft-Exchange-Diagnostics: 1;DB6PR0501MB2759;20: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;4:z21gYue/GcgZGXX2RfHxyVOJar1ocMwMMZexbSwRUfJLMJiKpyK58yuUCIUO5se9uNgA1rHoAAN7I3iq0QxKH7jqDTbBqVlavmAiXX/iRuZB/jVZ85dodZKGfK8bcGqrI4s8sVcufTyV1m1du0n/1b+yau4HUgDxpBvPtO+UNuEX/82CbaSL8wvKgBrrqipmvupcXzHQtyivfX/89/QbfHw98zqvx1RVDFJBmoCPIecRICfE6RNcdJ0XJrkN8GRwFoM+uqz7bbXGfJYN5puXJDbkFmp30yIcTudhqmTbh5U= X-Exchange-Antispam-Report-Test: UriScan:(171992500451332); X-Microsoft-Antispam-PRVS: X-Exchange-Antispam-Report-CFA-Test: BCL:0;PCL:0;RULEID:(100000700101)(100105000095)(100000701101)(100105300095)(100000702101)(100105100095)(6040450)(601004)(2401047)(5005006)(8121501046)(10201501046)(3002001)(100000703101)(100105400095)(93006095)(93001095)(6055026)(6041248)(20161123564025)(20161123558100)(201703131423075)(201702281528075)(201703061421075)(201703061406153)(20161123560025)(20161123562025)(20161123555025)(6072148)(201708071742011)(100000704101)(100105200095)(100000705101)(100105500095);SRVR:DB6PR0501MB2759;BCL:0;PCL:0;RULEID:(100000800101)(100110000095)(100000801101)(100110300095)(100000802101)(100110100095)(100000803101)(100110400095)(100000804101)(100110200095)(100000805101)(100110500095);SRVR:DB6PR0501MB2759; X-Forefront-PRVS: 03965EFC76 X-Forefront-Antispam-Report: SFV:NSPM;SFS:(10009020)(4630300001)(7370300001)(6009001)(6049001)(377454003)(24454002)(377424004)(189002)(199003)(53546010)(189998001)(53936002)(230700001)(6116002)(97736004)(3846002)(2906002)(101416001)(6246003)(7350300001)(36756003)(3260700006)(7416002)(76176999)(25786009)(5660300001)(23676002)(8666007)(117156002)(4326008)(68736007)(50986999)(478600001)(65826007)(54906002)(54356999)(83506001)(64126003)(50466002)(7736002)(93886004)(305945005)(31686004)(966005)(42186005)(106356001)(105586002)(6306002)(4001350100001)(47776003)(65806001)(33646002)(229853002)(65956001)(66066001)(8676002)(81156014)(86362001)(6666003)(77096006)(2950100002)(81166006)(31696002)(6486002)(217873001)(18886065003);DIR:OUT;SFP:1101;SCL:1;SRVR:DB6PR0501MB2759;H:[192.168.2.47];FPR:;SPF:None;PTR:InfoNoRecords;MX:1;A:1;LANG:en; X-Microsoft-Exchange-Diagnostics: =?utf-8?B?MTtEQjZQUjA1MDFNQjI3NTk7MjM6MmtGNE1ZQ0w0WUpIWVl1WCtoVE9makdt?= =?utf-8?B?dUh3c256Tks0bDM0cHVPcklBZmpIZkd3c01QM0hmeGVBUnlFNnFwdjdoVHZ2?= =?utf-8?B?a3M4dlgvcjdvMk80czhYN2NBajlINFVQZ1J1QTRaVWxNZmR3eEtqWDQwR3pP?= =?utf-8?B?RzhGMy9ZREd1aHhodm1lV2t3ck1kRWIwMjdjNUdqcCtPTzgwSmdBKzU2OW55?= =?utf-8?B?a3phTlBoNGtIVGlQNlZlcEp4K3ZBNzhFanlhUHJodG5jWlB0VnNlY3RnZFEx?= =?utf-8?B?aElXQ2NENDRjdVRoOUJpZXNYeEpMTG0vNUYyTU4zaWp5S2pnWVUxOW5UR2Ry?= =?utf-8?B?d2VhRlQ2MkF2WTgxa1ZLd0RONkJvakgrL2lKQ1V6Nm81TnJwc2RiWDRyTGJh?= =?utf-8?B?alpJcDBrS3kvUC9vMm5SNkFLdDM1ZUtJSlNOMitZVWNPN1h0ZXBuQ2daK2hD?= =?utf-8?B?cWVMV3VkQVNVQW9sWS9RSEJJRnl0cGxWd0swT0w5QkQ0QXBhYUwxeXNaZ3BT?= =?utf-8?B?dXRkRFhhS2pXTi9jUDZnV1pZQlNKS3pYQjB6ek9Hb1pjbmhaMUpESlRKcDhk?= =?utf-8?B?THJEWVZHVi9NU3U1SW82WnJRK3A5VkI1dGk5NGFCUmJvRVV0ZEdWTTVSYU5Q?= =?utf-8?B?LzRzTHRhaXRLOXk2emJhdHl1MHNJZlhoNGdHSEdub3F6SkcvRlQ3aTFYRjVz?= =?utf-8?B?b3VZaWl2MUdmOG1leHdodWZXQWJSYUtOcnhlODlCcmgwdnl2STUvanVJMWo2?= =?utf-8?B?aEUxUll5RHhvWFVpM1o4TEJEN20xL3lrWGd1MzBaVTdzZTFzWE5jR0F1Nm94?= =?utf-8?B?czJWZkI2My9WN2dOMVJ1R2MyamVvdzErRy9VaFRCMGJGTHFoeVFWWmk1bHlQ?= =?utf-8?B?TSsvVHljQ0Z6UU13Q3JpRGFnTTZTN0dJWlJZYnE4Wk9qVGYxak9ZOTZLaGd6?= =?utf-8?B?SWs2TG53YTdZVEd5NzJTMjdLaVY0eld2RFBxSDNvazhvYnE2RmlTaHJiRWRy?= =?utf-8?B?MktWaElCZDMvdm1qRGowNEpRTjR1cTl2NGJ6L3pqeDM5d29kSFdTNHlCZjdk?= =?utf-8?B?bDNYa3laSmJCWVR6VlRTemJNSWxmUmFYOXplcmkzWnF1ZklrY1ozNkNSVW9U?= =?utf-8?B?WGdxMjUwblJIUzJ3emlxNU1uekhiVzg4bk82TUVPcVV2WlRQOVJUeCtMNENV?= =?utf-8?B?WVBGcTFITGtaUXRpbFdKeFBPaSt1cml1SDdtd1JZTVk1bi9ZdG9LK3d3dS9B?= =?utf-8?B?MlliWTlhUDVacDIzMDhIMk9LdU1RRnNoSHlzUzB4MnhFVlA5RG9LdWJYRXAv?= =?utf-8?B?c2t6Yk5zQjc1b1ljUWpDNGN1QlE2M2d0WDJ5VC9peG1xZjVSZTNuL2FyUDFD?= =?utf-8?B?S1pjOHkwK3BTUWdEUlhFcGdONzVFZTVweVBNN2dxS1A2WEN0MXdBcHMwY3dk?= =?utf-8?B?cjUvQXhIQ1BOMGxrR3ZpL05QUU5EMS80eGIyM3poRGNrSkRqRE1hN0lzaHVQ?= =?utf-8?B?YXNvdmM0WVpwR2lDZ0J1MXVwOFo5UXI4L2ZNaktOaUpjRGV0dUg4N1YxMzVh?= =?utf-8?B?OWs0NCtFdlRkVU8zcUFCeVFXRVozVnRybVZPYWlmL0IxQXpkWE5sdWJyVUJF?= =?utf-8?B?V1RqOGJ6MTBRZXpYS296ZzErRDY1VnErVkZlaThBYXc0dFJmZDVYM0JtRFBn?= =?utf-8?B?UGx2YzZjVzY5MFdLWk5vWFFtVkRPeUlZTWZrQmhMWHQ3STBYaXZwYndRNUM3?= =?utf-8?B?QnZBYjNJYWl5MXFkNWZXbDBZdnNiN1g5MVVOR1VjdS95RUI2YjR4SDhzaUlr?= =?utf-8?B?b0VpQWt4bjJ6bUhSdUE2OUl2b2pyckhKVTRGejZ4azdHVkZ6WktHcDF4cy9D?= =?utf-8?B?T1V5NVJtSEt1eDkwSW9RQUtWcTlwL01XZXIvM3o4cmVUN3JSWWNsQnhZbFlp?= =?utf-8?B?SEhxeVhWQ1kwOVgxRVpERzlKb3VwVm90ODB6enRMMXoxUURnZEpZS2Nvckw5?= =?utf-8?B?akhPNTBBNWtDUkYwOUxPSEJIKzZ5TVNjVnpGMnFWMHpjTGxnTkcwT0hiYnZP?= =?utf-8?B?aytRTEdKKzIyYTV0S3VibkVSaExkNHMzdmZEUzdBMUpnWGREMDZCb3p2eDh5?= =?utf-8?B?bW83UT09?= X-Microsoft-Exchange-Diagnostics: 1;DB6PR0501MB2759;6:JDXMh0+OyHCYFXWwcdPIvtwrFfUa72x0pvTZIuiKdtupC3rn7zccCwIgt8y8+QIc1IbcMCUoVFQ8rkdB1j9DH7bRYPX43GNYSfA5pjeHo6Has+E49EtRFtBmwWu9NIxO3rO1XSOYL4p8tQBW52pa4J9b07rIIK/mbDVPuk7C48ApD3zBw2bCvrqMfOLbBguJDhAcEtvUN+mhJgUT05OZDgfaeyGnNGIdIQjm7H4Xdvn+pT9jUmnDIRDKQdK/1eDyucGGOn2Dnsf5hF1qZzIgcWC6pak+fAsghhb+uNAtt3ska/a4dGyTANcN0nO53xiXsG2QMK1SMp/sLl8cpWHmhg==;5:15DRPBBNiQ7z54+r/NjNoWfbYJWiI/OsbFTRWnlBwLuYAtATloJaO0amOwEs6hK+cHV4C4sFrX8rWW3OnjVUGcmDJa/Om5EP+PJTJQ/vTtck2SC8Rd2DXLmgcXMdQG8GogiYPiSAStvHRT1cd/vwiQ==;24:JNBMTxkUYpAx8PA7Fh9/saRZjYVe2EIpTCq6wC9rl0VstmJby4OroH59++0Fp4/fksuRU/b+WRgwOss6dZyanPNowaNjCxTDaJ6tpT33LP8=;7:+NVakXNULES7Im67VHSLcig/WbWm1Hycn9HLdSSvjk5ep+mwreBMoJpCeGzp6JXDLJ4nTKjeN20daKNpKAHxzovRyVfRKDr8AKilRQp0a6z1925lCQkxx0bkVZbh1MJ3Aa/1ybcaaaW6F1yCvm2QQDAZFvB0E6S0sN2aUA3PlOG05iPnyftWpmxjUxYThE/ADDp2J9XL7Hj01blTPk/e4+0ycgYQg50bxqgRt9gR7Mg= SpamDiagnosticOutput: 1:99 SpamDiagnosticMetadata: NSPM X-OriginatorOrg: Mellanox.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 11 Aug 2017 15:08:17.7955 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-Transport-CrossTenantHeadersStamped: DB6PR0501MB2759 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1183 Lines: 22 On 8/11/2017 2:36 AM, Mike Galbraith wrote: > On Thu, 2017-08-10 at 09:57 -0400, Chris Metcalf wrote: >> On 8/10/2017 8:54 AM, Frederic Weisbecker wrote: >>> But perhaps I should add a new NO_HZ_FULL_BUT_HOUSEKEEPING option. >>> Otherwise we'll change the meaning of NO_HZ_FULL_ALL way too much, to the point >>> that its default behaviour will be the exact opposite of the current one: by default >>> every CPU is housekeeping, so NO_HZ_FULL_ALL would have no effect anymore if we >>> don't set housekeeping boot option. >> Maybe a CONFIG_HOUSEKEEPING_BOOT_ONLY as a way to restrict housekeeping >> by default to just the boot cpu. In conjunction with NOHZ_FULL_ALL you would >> then get the expected semantics. > A big box with only the boot cpu for housekeeping is likely screwed. Fair point - this kind of configuration would be primarily useful for dedicated systems that were running a high-traffic-rate networking application on many cores, for example. In this mode you don't end up putting a lot of burden on the housekeeping core. In any case, probably not worth adding an additional kernel config for. -- Chris Metcalf, Mellanox Technologies http://www.mellanox.com