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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id F12A3C36010 for ; Tue, 1 Apr 2025 13:57:27 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 130DF280004; Tue, 1 Apr 2025 09:57:26 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 0E025280001; Tue, 1 Apr 2025 09:57:26 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id EC032280004; Tue, 1 Apr 2025 09:57:25 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id C99AF280001 for ; Tue, 1 Apr 2025 09:57:25 -0400 (EDT) Received: from smtpin03.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id D0167802CE for ; Tue, 1 Apr 2025 13:57:26 +0000 (UTC) X-FDA: 83285627292.03.81EFE90 Received: from NAM10-DM6-obe.outbound.protection.outlook.com (mail-dm6nam10on2069.outbound.protection.outlook.com [40.107.93.69]) by imf18.hostedemail.com (Postfix) with ESMTP id DCD271C000B for ; Tue, 1 Apr 2025 13:57:23 +0000 (UTC) Authentication-Results: imf18.hostedemail.com; dkim=pass header.d=amd.com header.s=selector1 header.b="Jvi/eUOz"; dmarc=pass (policy=quarantine) header.from=amd.com; arc=pass ("microsoft.com:s=arcselector10001:i=1"); spf=pass (imf18.hostedemail.com: domain of Nikhil.Dhama@amd.com designates 40.107.93.69 as permitted sender) smtp.mailfrom=Nikhil.Dhama@amd.com ARC-Seal: i=2; s=arc-20220608; d=hostedemail.com; t=1743515844; a=rsa-sha256; cv=pass; b=RZFvcedSM3XTDMmU1XHZCmbcpIdMiNWXrTeP6kkuguYmXdLeo6mi/jc5PKFNJ4E6R6aMGh fgv5VLP61UcbrxK9EI64K5Xo4hW0M5lM42m7BN0nFfVH4pgExngb5KJh6Peyvr/YJRjRFz 26UhZs5UCcrhoDuculDmaOJ1kDMqel0= ARC-Authentication-Results: i=2; imf18.hostedemail.com; dkim=pass header.d=amd.com header.s=selector1 header.b="Jvi/eUOz"; dmarc=pass (policy=quarantine) header.from=amd.com; arc=pass ("microsoft.com:s=arcselector10001:i=1"); spf=pass (imf18.hostedemail.com: domain of Nikhil.Dhama@amd.com designates 40.107.93.69 as permitted sender) smtp.mailfrom=Nikhil.Dhama@amd.com ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1743515844; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=5+ONV7n8KEuhdBr3MlPs2Zi1tt7JAfVRENI0P3VxEBw=; b=X8tIHY7Kz+XsmzQcwjVTFkYMLuSeCeZSeXl8eVGmkzJyyT+IfsA0sw/yAQQ85HBKLI4mld N5GKg4MOomjv/x5ainKPbwBOgIFhJ98/h48xWMCg3z0MRc3wLSkQ2hEMcqaFu6tlMZSowP QtuP7iCkUBP5sXC7/lef+33lV9RobVI= ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=thzbNun7ZF3xJQz/pY69IDsDwSjOu8nf8TgnZ7FPepRzLP447XMtWDG9wobJar9KYWhDyY2MQeu8a1MbtTftzOrZi7zPErLDfqsxIR9s+QFlthG8B3UiSjCiSlLFDK/pBOerTzgDdRTbWYXLD9JnELZnnQFBCdEx67JNp5YSuMqRlG1RO6LpK2a4/I1xQPkG86liASs4seZduAR0NBRGsUnKe6OHKZyyvXM5kVHvouZox0X09eGhwDMVIFcgSYqS6fsDtvQWdmmh+xQR3ZQP4AGLMnI08bVQbjkeQ2PT9T1TFXYRXjyfC5o7c1/9LvUZbDzzY9npoZme8MzWoKEVVA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; 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=5+ONV7n8KEuhdBr3MlPs2Zi1tt7JAfVRENI0P3VxEBw=; b=E/2tfiwov46CPRD3kPIEdF0xLi+BarkJZpmA4UVdfYIDz0u13BGg3AD6eQ/XP/20prNVOs0OTiPfGBqlccZkDH4kPgNirfJne2V91SjDzeFu0MBNhWfOz+nQlrPAN0zvgEo0wa8GbslVi3ief83ksQD9kBWxK+gz+KpMpMg0lKOWG28Oy3WRp7CL7KjyrEjmEH9P6iwyONas4uG1K5tN+715cllYrbrmVnP9JFkFDvwGmSv7AUA4D7lW9HQtvPlxvbYArlqPw3JjGlPKdC0E88jPPXLbDFdoPjxcl9KyM8zVaBqBPiudNNUcgUVoKoo9EAptZC0/PCB2qrGj0Yj5cQ== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass (sender ip is 165.204.84.17) smtp.rcpttodomain=linux.alibaba.com smtp.mailfrom=amd.com; dmarc=pass (p=quarantine sp=quarantine pct=100) action=none header.from=amd.com; dkim=none (message not signed); arc=none (0) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amd.com; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=5+ONV7n8KEuhdBr3MlPs2Zi1tt7JAfVRENI0P3VxEBw=; b=Jvi/eUOz7AhNNZAG84GrWpp6Y41PMQNFXAExN46A8QAY60wNWYH5Ege2vnhipE/7+R34w9ib1TSymYLosdTAutQIO+YELjl0vobsL85EXPhjKFzdQoFDOk2+oyfOYRh6nx7NaX9RdlVVWzIYoVlyupIr7bhasZTDIwRS/VPm0E0= Received: from MW4PR03CA0179.namprd03.prod.outlook.com (2603:10b6:303:8d::34) by CY1PR12MB9603.namprd12.prod.outlook.com (2603:10b6:930:108::8) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.8534.45; Tue, 1 Apr 2025 13:57:21 +0000 Received: from SJ1PEPF000023D1.namprd02.prod.outlook.com (2603:10b6:303:8d:cafe::e4) by MW4PR03CA0179.outlook.office365.com (2603:10b6:303:8d::34) with Microsoft SMTP Server (version=TLS1_3, cipher=TLS_AES_256_GCM_SHA384) id 15.20.8534.54 via Frontend Transport; Tue, 1 Apr 2025 13:57:21 +0000 X-MS-Exchange-Authentication-Results: spf=pass (sender IP is 165.204.84.17) smtp.mailfrom=amd.com; dkim=none (message not signed) header.d=none;dmarc=pass action=none header.from=amd.com; Received-SPF: Pass (protection.outlook.com: domain of amd.com designates 165.204.84.17 as permitted sender) receiver=protection.outlook.com; client-ip=165.204.84.17; helo=SATLEXMB04.amd.com; pr=C Received: from SATLEXMB04.amd.com (165.204.84.17) by SJ1PEPF000023D1.mail.protection.outlook.com (10.167.244.7) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.20.8606.22 via Frontend Transport; Tue, 1 Apr 2025 13:57:20 +0000 Received: from spgblr-titan-01.amd.com (10.180.168.240) by SATLEXMB04.amd.com (10.181.40.145) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.39; Tue, 1 Apr 2025 08:57:17 -0500 From: Nikhil Dhama To: , CC: , , , , , , , , Nikhil Dhama Subject: Re: [PATCH] mm: pcp: scale batch to reduce number of high order pcp flushes on deallocation Date: Tue, 1 Apr 2025 19:26:38 +0530 Message-ID: <20250401135638.25436-1-nikhil.dhama@amd.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <202503312148.c74b0351-lkp@intel.com> References: <202503312148.c74b0351-lkp@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-Originating-IP: [10.180.168.240] X-ClientProxiedBy: SATLEXMB03.amd.com (10.181.40.144) To SATLEXMB04.amd.com (10.181.40.145) X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: SJ1PEPF000023D1:EE_|CY1PR12MB9603:EE_ X-MS-Office365-Filtering-Correlation-Id: 8dcf98b6-36fd-493f-eb37-08dd71251f5f X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|82310400026|1800799024|36860700013|376014; X-Microsoft-Antispam-Message-Info: =?us-ascii?Q?wf5f/L6sbCT3W0w7bHouZEQpt/vt5HOe0jWNiH50O98YA4mTmDSkAkkJ2KS+?= =?us-ascii?Q?wmhJCri0DOZr3LVIn2HFeTeRVkKxhGe7z9FCN3zbMcEyyVN3ZH1wqWMXPDBZ?= =?us-ascii?Q?pvhg9EL2O+FAMTD9D/ghYjon9tKt04DCeV0iR2+X1FQof2DqwdBAeORfxKP0?= =?us-ascii?Q?99kGtKdRysCOUtEZx4nEc9NodcdGO8qS4lfEkH/5R73ACg2eyvd/OGzrI7aq?= =?us-ascii?Q?6OGR/B1xN7ymQHabOCo4Xg8YAl2SUHJuIzTd7ztP18GtAh/ZR8WaI1iodEqr?= =?us-ascii?Q?GyFtb/t6Yh0KgtDzYxVFonOWSfbPD8akAFNgwV305DwZv4RtxVJnCw9duK9v?= =?us-ascii?Q?gk0z8JE6qHOEff283f0HrsSfaOy3jfYzBgvk+oHnM2XY76enaFfha4pCOy7k?= =?us-ascii?Q?k2LoZZMoMW+hwP/tVZIV8Hu/7d2KImDsZ24aofFAwhSCmbQ+zbrMREaBERRb?= =?us-ascii?Q?ML8d7srLPWge14S+s9RuNYPEkdBiBFw2zbzOn9RVSuR0nVViGRvYcEDUUYT1?= =?us-ascii?Q?V7AoadZw5MrZd0U3TK5neyY0/+wuqQNn3tlnzFahEKZa+1r3aIswFQd8VJ4E?= =?us-ascii?Q?SVmg21/mohfCF5gryADCrt7B25wtA8Kn9PrsWaqb3M8+6Hwc/tpmxb61f2aa?= =?us-ascii?Q?CQ8Ua/qUDPqkp99mW8SwXOfgOiKTer17XOxTrPHhPogQWH3/pINTUx20+j7D?= =?us-ascii?Q?o/eNWIWWhqwoIKETzRWOsWqDUhdoAeauMrCUMXlXaQ+QSxQODobshw0FP5fp?= =?us-ascii?Q?sPQORcFCE7vvWa11iR+iHXB3ae6g3k12NREMt58u3sHCAa8l51eL/d5WRLJN?= =?us-ascii?Q?S5tVWwHj3ev5++jerJpzpF1DYLWC/eO7qjEzSx+YEO9PB91IIrNB0sDvdY6u?= =?us-ascii?Q?XV9aCsZd8Pw1KlclaYXUpFhJY8n5+5c/dtFWNJ4jh41QS1Qo0c7zSVBA2Hoc?= =?us-ascii?Q?wgeFS7OdypdUGq0xjwsBAkQFKn4Gw6UNFlEKQr5FUauEMA5Z16FoBuL2Pi71?= =?us-ascii?Q?NS+rrtFn8iylv0N6E3j+jjkGk6EBjO68++KHzmHtwGEuOWFEcRSA+p00LS7n?= =?us-ascii?Q?6cVPpuCniQ8bq+p/iCrM84INy5+DpIGJZIPbJSv3eilDiEjlfxNeLMYGUleq?= =?us-ascii?Q?Sm6kzvFMMtAkeArCxbY/hZbnmyyNxYGmfSp+zM1FgJkVtWZNqsXWuzMH6+yG?= =?us-ascii?Q?ErIhdD6IO4pmVi78Nv8bpHJy2bwLiREtLayZuHk0f+aOKYPhB7+T+WU/AYxJ?= =?us-ascii?Q?anSCgB4CsyRUDbnMWXwVV49y4qByeVIr6pd61oNJnrbcT0M0/t+nGdggalTS?= =?us-ascii?Q?zE9xXIILZZZoUAg3Bnaemfn1HKfS2qniYQrjFXN+BvkGfS0At1tbwGvvT5VF?= =?us-ascii?Q?fm4pNxlVC1lXEWtOsFqMo8EDK3AzMsC26F5kq4G/ImHY9zWPC0r+LWvhTwVV?= =?us-ascii?Q?tWFkRzGTkcW5v5dFKSDM+eqosvQkhmNL2e/kKE75bEqpDV7K5b65yEYfZlSS?= =?us-ascii?Q?1AumropeBA/amGM=3D?= X-Forefront-Antispam-Report: CIP:165.204.84.17;CTRY:US;LANG:en;SCL:1;SRV:;IPV:CAL;SFV:NSPM;H:SATLEXMB04.amd.com;PTR:InfoDomainNonexistent;CAT:NONE;SFS:(13230040)(82310400026)(1800799024)(36860700013)(376014);DIR:OUT;SFP:1101; X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 01 Apr 2025 13:57:20.9180 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 8dcf98b6-36fd-493f-eb37-08dd71251f5f X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=3dd8961f-e488-4e60-8e11-a82d994e183d;Ip=[165.204.84.17];Helo=[SATLEXMB04.amd.com] X-MS-Exchange-CrossTenant-AuthSource: SJ1PEPF000023D1.namprd02.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: CY1PR12MB9603 X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: DCD271C000B X-Stat-Signature: tii87eg63a1nzi8ttjrcg64ad1qoroqm X-Rspam-User: X-HE-Tag: 1743515843-647026 X-HE-Meta: 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 mKS+FQ2o 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 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: List-Subscribe: List-Unsubscribe: On 3/30/2025 12:22 PM, Huang, Ying wrote: > > Hi, Nikhil, > > Nikhil Dhama writes: > >> In old pcp design, pcp->free_factor gets incremented in nr_pcp_free() >> which is invoked by free_pcppages_bulk(). So, it used to increase >> free_factor by 1 only when we try to reduce the size of pcp list or >> flush for high order. >> and free_high used to trigger only for order > 0 and order < >> costly_order and free_factor > 0. >> >> and free_factor used to scale down by a factor of 2 on every successful >> allocation. >> >> for iperf3 I noticed that with older design in kernel v6.6, pcp list was >> drained mostly when pcp->count > high (more often when count goes above >> 530). and most of the time free_factor was 0, triggering very few >> high order flushes. >> >> Whereas in the current design, free_factor is changed to free_count to keep >> track of the number of pages freed contiguously, >> and with this design for iperf3, pcp list is getting flushed more >> frequently because free_high heuristics is triggered more often now. >> >> In current design, free_count is incremented on every deallocation, >> irrespective of whether pcp list was reduced or not. And logic to >> trigger free_high is if free_count goes above batch (which is 63) and >> there are two contiguous page free without any allocation. >> (and with cache slice optimisation). >> >> With this design, I observed that high order pcp list is drained as soon >> as both count and free_count goes about 63. >> >> and due to this more aggressive high order flushing, applications >> doing contiguous high order allocation will require to go to global list >> more frequently. >> >> On a 2-node AMD machine with 384 vCPUs on each node, >> connected via Mellonox connectX-7, I am seeing a ~30% performance >> reduction if we scale number of iperf3 client/server pairs from 32 to 64. >> >> So, though this new design reduced the time to detect high order flushes, >> but for application which are allocating high order pages more >> frequently it may be flushing the high order list pre-maturely. >> This motivates towards tuning on how late or early we should flush >> high order lists. >> >> for free_high heuristics. I tried to scale batch and tune it, >> which will delay the free_high flushes. >> >> >> score # free_high >> ----------- ----- ----------- >> v6.6 (base) 100 4 >> v6.12 (batch*1) 69 170 >> batch*2 69 150 >> batch*4 74 101 >> batch*5 100 53 >> batch*6 100 36 >> batch*8 100 3 >> >> scaling batch for free_high heuristics with a factor of 5 or above restores >> the performance, as it is reducing the number of high order flushes. >> >> On 2-node AMD server with 384 vCPUs each,score for other benchmarks with >> patch v2 along with iperf3 are as follows: > > Em..., IIUC, this may disable the free_high optimizations. free_high > optimization is introduced by Mel Gorman in commit f26b3fa04611 > ("mm/page_alloc: limit number of high-order pages on PCP during bulk > free"). So, this may trigger regression for the workloads in the > commit. Can you try it too? > Hi, I ran netperf-tcp as in commit f26b3fa04611 ("mm/page_alloc: limit number of high-order pages on PCP during bulk free"), On a 2-node AMD server with 384 vCPUs, results I observed are as follows: 6.12 6.12 vanilla freehigh-heuristicsopt Hmean 64 732.14 ( 0.00%) 736.90 ( 0.65%) Hmean 128 1417.46 ( 0.00%) 1421.54 ( 0.29%) Hmean 256 2679.67 ( 0.00%) 2689.68 ( 0.37%) Hmean 1024 8328.52 ( 0.00%) 8413.94 ( 1.03%) Hmean 2048 12716.98 ( 0.00%) 12838.94 ( 0.96%) Hmean 3312 15787.79 ( 0.00%) 15822.40 ( 0.22%) Hmean 4096 17311.91 ( 0.00%) 17328.74 ( 0.10%) Hmean 8192 20310.73 ( 0.00%) 20447.12 ( 0.67%) It is not regressing for netperf-tcp. Thanks, Nikhil Dhama