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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E8466C433F5 for ; Thu, 5 May 2022 08:27:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347829AbiEEIbE (ORCPT ); Thu, 5 May 2022 04:31:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41550 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1347434AbiEEIbA (ORCPT ); Thu, 5 May 2022 04:31:00 -0400 Received: from mga07.intel.com (mga07.intel.com [134.134.136.100]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 493B62D1EB for ; Thu, 5 May 2022 01:27:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1651739241; x=1683275241; h=date:from:to:cc:subject:message-id:references: in-reply-to:mime-version; bh=M952Nmejm69YsvjtZ+4uKwszT2KJJdyDJgIJNHRhNQ0=; b=N/f3Q+fT15RcnwJo+q8ZnlpBwmXAnlG4xJki38o2t2VmlJh9niqmTdTu r3o7SvmRBkCrFKExQ50dhLQeyfrL9MTb8ilQQRMX27nw8tnfxKqNmkyS3 iKC29t+Hz37fbtOE3T2ZakZ0J+Jy0eHN1J9i1e6wiWdhJlCj5GDIzxt5m 2NwrQ+RJB7dJ7zXK8yN7L3naO+nNY/WxVEgCfgEvidCPcdmQGXdGc/H8e R/Ipu6tq8mYyc9svxbXoPduGUcdOv7Dqqpb1mvHkWh04Ox5gaOvuA+yxH f0u1ChNzPlbM2LELPEvedz80JGbZEsIsnIrK9sEsIlPxl7Fue2V3DtN70 A==; X-IronPort-AV: E=McAfee;i="6400,9594,10337"; a="331029651" X-IronPort-AV: E=Sophos;i="5.91,200,1647327600"; d="scan'208";a="331029651" Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 May 2022 01:27:20 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.91,200,1647327600"; d="scan'208";a="599954439" Received: from fmsmsx602.amr.corp.intel.com ([10.18.126.82]) by orsmga001.jf.intel.com with ESMTP; 05 May 2022 01:27:20 -0700 Received: from fmsmsx612.amr.corp.intel.com (10.18.126.92) by fmsmsx602.amr.corp.intel.com (10.18.126.82) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.27; Thu, 5 May 2022 01:27:20 -0700 Received: from fmsmsx608.amr.corp.intel.com (10.18.126.88) by fmsmsx612.amr.corp.intel.com (10.18.126.92) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.27; Thu, 5 May 2022 01:27:19 -0700 Received: from FMSEDG603.ED.cps.intel.com (10.1.192.133) by fmsmsx608.amr.corp.intel.com (10.18.126.88) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.27 via Frontend Transport; Thu, 5 May 2022 01:27:19 -0700 Received: from NAM11-BN8-obe.outbound.protection.outlook.com (104.47.58.168) by edgegateway.intel.com (192.55.55.68) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2308.27; Thu, 5 May 2022 01:27:19 -0700 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=iGdXJIwFLqrsGOa06PZ9EGVqEUOB3y7XMk3kmqqEUteTVmGgCbBz8Eel6HWOka29EHob6ZDi+fSsIWB5O0XQic621P7CRbB0/zFbr5KgntMFnBG6wv9j1zXpPgYdEWnE34CVVN63hxCL8vFXF9obna+/MeU9m4BIzDpiG9I4BAMfljJImXALoOvMiz+mZ9oD3ttgmWC2GzMQMvOGEEQW5uLxT0l6SPA5277vxYhvIZLmN/32torUQy/PIOi9M8ynjhVbSy+++fdBCwP4BHTl5t4WxbD4AxayAtcb37xwmu8g8dBpYFZ8foJouAdlz1lrsDLuNLn/4WmBJ/h8AJn2uA== 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-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=1CcLh0qw+5eYhaSMj1ZsRQntME2ofHcXEhtoC7X9n6U=; b=XaSQNfZg9GvZxV8eWTaT/7M6pYYV1iJa4nH43D6tmwotLUe2NsqGYJ0lQhs7NAPx1zVI1jOUhTqC3FGlI6ho0V557m8X+pcAfvkCKWekNKyi9QSBFBQTMA6bt7KoJPW7irmIGC135jXXLJdj4hnxXDO9dycz4SSeV/fLeUC3f3ePRhBgauu0wxNqx6LbY1qnpm0ecOi8MLtjF2DCvg8+6IL7tkt2Y7jF+S5zcetfMcUJ0LwhZYRnnlq4WDBJBUaeQMJuwf16qzMtQ/XTX7X/sPo1vS01m2yjMzDLWzMFRbAqMakIu14ld02dPaMGFaTv5LOkb6rYUU2izordOl+I3w== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=intel.com; dmarc=pass action=none header.from=intel.com; dkim=pass header.d=intel.com; arc=none Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=intel.com; Received: from BYAPR11MB3062.namprd11.prod.outlook.com (2603:10b6:a03:92::18) by DM6PR11MB4345.namprd11.prod.outlook.com (2603:10b6:5:202::20) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.5206.25; Thu, 5 May 2022 08:27:17 +0000 Received: from BYAPR11MB3062.namprd11.prod.outlook.com ([fe80::90eb:f194:6b40:c4ff]) by BYAPR11MB3062.namprd11.prod.outlook.com ([fe80::90eb:f194:6b40:c4ff%5]) with mapi id 15.20.5206.027; Thu, 5 May 2022 08:27:17 +0000 Date: Thu, 5 May 2022 16:27:04 +0800 From: Aaron Lu To: Mel Gorman CC: kernel test robot , Linus Torvalds , Vlastimil Babka , "Dave Hansen" , Jesper Dangaard Brouer , Michal Hocko , Andrew Morton , LKML , , , , , , Subject: Re: [mm/page_alloc] f26b3fa046: netperf.Throughput_Mbps -18.0% regression Message-ID: References: <20220420013526.GB14333@xsang-OptiPlex-9020> <20220429133918.GC3441@techsingularity.net> Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <20220429133918.GC3441@techsingularity.net> X-ClientProxiedBy: HK2PR0302CA0019.apcprd03.prod.outlook.com (2603:1096:202::29) To BYAPR11MB3062.namprd11.prod.outlook.com (2603:10b6:a03:92::18) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: 75b2f102-f241-4f4c-ece6-08da2e711094 X-MS-TrafficTypeDiagnostic: DM6PR11MB4345:EE_ X-LD-Processed: 46c98d88-e344-4ed4-8496-4ed7712e255d,ExtAddr X-Microsoft-Antispam-PRVS: X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 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:BYAPR11MB3062.namprd11.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230001)(7916004)(366004)(316002)(26005)(86362001)(66476007)(6916009)(66946007)(66556008)(8676002)(38100700002)(83380400001)(508600001)(82960400001)(7416002)(8936002)(44832011)(6486002)(5660300002)(186003)(2906002)(6666004)(9686003)(54906003)(4326008)(6512007)(6506007)(33716001);DIR:OUT;SFP:1102; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?uLA+rz0Vypy7Dv2gYh1s9BvBY3/yd5DtGEx3w9nWpeoEsK467peMUxplyPaY?= =?us-ascii?Q?g9VrcEv069zI6wafjPHcOamaT8mEf9fHQ+DzLvxKFABMQD7k/WQTfCK20Inq?= =?us-ascii?Q?styhdHrE54/GwwIB5HLlshEDm6kQDFn2hIC3M0qIZnNAsmF80fzdH3OpqyEf?= =?us-ascii?Q?IdMOMKx3jYk8a1L6D+DBDM47Dgsx5AMXAt2NGh+GWdXW/uyITAZcuNpAxlIV?= =?us-ascii?Q?q2lLWB6TJHzSLYKF9rtkFU8XPNZitsFza7IAtL0tZnOMKa27rAIvVwbJIsHF?= =?us-ascii?Q?dq2povKZX0veaTjXDHotliLYvffKwzppinln/shRGB5i7bFK2YO5aDHUvLzf?= =?us-ascii?Q?Z668jsQuroSkqv7Et8z2n4B3PUGqhEVnksu9bIE2uwhKbQSFrADAw1JDKQzp?= =?us-ascii?Q?6zCIPapzY7W59QEZVozE4lBe7uhqQ7hAbJGXdEqY8Jnm+qQrO2vfxgi6MC6E?= =?us-ascii?Q?Hs7Te3xPly4+ZlwKp37jUG7lO7utOU0s9nkAKoLD1oLn0jcAW3pRpIGBkeqY?= =?us-ascii?Q?cJvnVPgx3v/eNKMZQKHLcquwfkLf9GTx1PDMO7QpIzhpoIcjEu25UV5DXZwW?= =?us-ascii?Q?ftUXlh1avWdzmKLOyT4eRdNy6VY0Ybp1sTUFVmhZh2VpGCj5Tcg5lQm6jpAw?= =?us-ascii?Q?kIPKTtpbg/MCmcM/v9kj9cQYF9vV1FFwhyPGDXu1EZjZHTyc6IRVlzNi+XKe?= =?us-ascii?Q?A1X4kt7nZoCqpdeFNssTm600ZcN0//1H9eVksXZAbiM4vYCpwRhY73D8fMxt?= =?us-ascii?Q?NFXKKOnLeMEvubTwgXANcZreoFg8sAaH69WWhQt7bzqkmWlqkWk7Se9/mJW7?= =?us-ascii?Q?kwFw7+hhe5kZ18tECjyVnobtdB0tLDIlZ14yjtEDtlOqiugwxNvaS1O7kbzu?= =?us-ascii?Q?AJWU1MRBIzAqn08/COqw0aAeIeV5PAieSuC4QfxGvXsgM9XXPkiCzIHWFy31?= =?us-ascii?Q?hjjE/ZNXMLb0XwfYmgf8mr93CcwrHUC1Rxa0i1F+rRhimCFBhcKwgXXLmEab?= =?us-ascii?Q?PSyTdHflVm6Qjek1ySDOfI/pEUr1ft36KAmR6+luO0Wj/j/BMYBd8ic0bvlr?= =?us-ascii?Q?fzHBzLt16LyBAYlWZ4JTyDJTmioaiZLR4/kNpX3SY46jKU0v5uEHekXAdsG/?= =?us-ascii?Q?HgkIUyTGKCPzVRMEFuORC4d1dsr7F8B6kCIAQ4VMkWDeOFTZcwe4dl9FT7WA?= =?us-ascii?Q?xOCB4T7IQ0rJ9h8e6YGRx4ThdysmspetaYexOMybV8z0UN5+FEvV39e9z0UE?= =?us-ascii?Q?suxqQSVQTChs+ryuh3xyLGaSMSOGPM//Llpau8G1ur7IJkMLbDdf996q/fuN?= =?us-ascii?Q?UP6aMp21JtrQbIDcsTZNcBfH0yGpsS+/FCekAn/zWwKKHTRqy2JINiXGZYEv?= =?us-ascii?Q?l/EFsYUv2k3vZLpX5OSyitX5uaqgVbpnZRLB5o9SXeDzuIo+vRtZRK5MffZd?= =?us-ascii?Q?jBcGVq0nxy2aok5XMKGDSNU1T0/+9/r+Gr1aqPuwNfsIDM6zVkcE9m09J3lx?= =?us-ascii?Q?FIaZZmOgZcksPkOggpNymZeZ50NoS3ZtF4ro5ujeC7WoMiZ/Dg2EJkQEZBJw?= =?us-ascii?Q?23DhukbbY92mS/FV160GOMZhpUYebESk/M28GZRqoN6BndScXmnHh6RbL+AU?= =?us-ascii?Q?XlCYEGjsMiJ0tbRzdNVlxfy4P+EQ6K0GJWqsVfs4EuhR1UrWBY4bMq4idvAX?= =?us-ascii?Q?hAmp2aZ4DlrVvMRXS3UEaYuwk2DaFMUQdmPquDavmZGvWbwJnfECXrgnM5SP?= =?us-ascii?Q?wnWfdWtouw=3D=3D?= X-MS-Exchange-CrossTenant-Network-Message-Id: 75b2f102-f241-4f4c-ece6-08da2e711094 X-MS-Exchange-CrossTenant-AuthSource: BYAPR11MB3062.namprd11.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 05 May 2022 08:27:17.2130 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 46c98d88-e344-4ed4-8496-4ed7712e255d X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: pUOfJs/LozO7qbJovusPwqm06WTG7V30aw1LPoonMxseOkFd7MmKO1cckJOU0K1rHAj2JFPOs8IWY5ZDlYFjZg== X-MS-Exchange-Transport-CrossTenantHeadersStamped: DM6PR11MB4345 X-OriginatorOrg: intel.com Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Apr 29, 2022 at 02:39:18PM +0100, Mel Gorman wrote: > On Fri, Apr 29, 2022 at 07:29:19PM +0800, Aaron Lu wrote: ... ... > > The said change looks like this: > > (relevant comment will have to be adjusted) > > > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > > index 505d59f7d4fa..130a02af8321 100644 > > --- a/mm/page_alloc.c > > +++ b/mm/page_alloc.c > > @@ -3332,18 +3332,19 @@ static int nr_pcp_high(struct per_cpu_pages *pcp, struct zone *zone, > > bool free_high) > > { > > int high = READ_ONCE(pcp->high); > > + int batch = READ_ONCE(pcp->batch); > > > > - if (unlikely(!high || free_high)) > > + if (unlikely(!high)) > > return 0; > > > > - if (!test_bit(ZONE_RECLAIM_ACTIVE, &zone->flags)) > > - return high; > > - > > /* > > * If reclaim is active, limit the number of pages that can be > > * stored on pcp lists > > */ > > - return min(READ_ONCE(pcp->batch) << 2, high); > > + if (test_bit(ZONE_RECLAIM_ACTIVE, &zone->flags) || free_high) > > + return min(batch << 2, high); > > + > > + return high; > > } > > > > static void free_unref_page_commit(struct page *page, int migratetype, > > > > Does this look sane? If so, I can prepare a formal patch with proper > > comment and changelog, thanks. > > I think it looks reasonable sane. The corner case is that if > ((high - (batch >> 2)) > cachesize) that the pages will not get recycled When free_high is true, the above diff changed the return value of nr_pcp_high() from 0 to min(batch << 2, pcp->high) so the corner case is when (min(batch << 2, pcp->high) > cachesize)? > quickly enough. On the plus side always freeing to buddy may contend on the > zone lock again and freeing in batches reduces that risk. > > Given that zone lock contention is reduced regardless of cache size, it > seems like a reasonable tradeoff. Glad to hear this.