From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=pass header.oldest-pass=0 smtp.remote-ip=40.107.201.46 ARC-Seal: i=2; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=pass; t=1792983087; b=e1Kpr96vilywDFeC5t4qE1wZphoCPITZQXx2KvTNfL11v9sQf0wtTHfYx276BLrk715h ygABRm7TscyJywZmRfSGxqRVXnhhNRrLZy1JcUQGl02zBGSvBW9syo8ZZjRsoKWqS0O7y dJdhfGHkCpli8V0OY2h4M0MUcViv2CmNqWnvFcaY46kO7cdQKcUNksgwpSVJ4wU9XN+p6 Tjut8aEEAmoAeT42qgsLyPhRSpuT1nXLMe90FLNzYRhF6wxChiK+VowSDzFPJZl1I40l9 RJ1O2IRpUaeXI3oSACQFiJ1RBDU7bn6+/r+mn+AYKWSh9vphvi9ebyRep0V8lB3+XTA== ARC-Message-Signature: i=2; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792983087; h=DMARC-Filter:DKIM-Signature:Received:Received:Date:From:To:Cc: Subject:Message-ID:References:Content-Type:Content-Disposition: In-Reply-To:X-ClientProxiedBy:MIME-Version:X-MS-PublicTrafficType: X-MS-TrafficTypeDiagnostic:X-MS-Office365-Filtering-Correlation-Id: X-MS-Exchange-SenderADCheck:X-MS-Exchange-AntiSpam-Relay: X-Microsoft-Antispam:X-Microsoft-Antispam-Message-Info: X-Forefront-Antispam-Report: X-MS-Exchange-AntiSpam-MessageData-ChunkCount: X-MS-Exchange-AntiSpam-MessageData-0:X-OriginatorOrg: X-MS-Exchange-CrossTenant-Network-Message-Id: X-MS-Exchange-CrossTenant-AuthSource:X-MS-Exchange-CrossTenant-AuthAs: X-MS-Exchange-CrossTenant-OriginalArrivalTime: X-MS-Exchange-CrossTenant-FromEntityHeader: X-MS-Exchange-CrossTenant-Id:X-MS-Exchange-CrossTenant-MailboxType: X-MS-Exchange-CrossTenant-UserPrincipalName: X-MS-Exchange-Transport-CrossTenantHeadersStamped; bh=G6OsTiixpt5M1jc2jalslJkV4KaBfj1Z1QWDgxtaVRk=; b=r9KXb3tDMI1a5Oxk4XqqDuYfYbFdVXtQZOfZScTBR+lepncMewWk21KvV4PtpvrwNQOO s0/GwDOipK+qGWraXQE4XxDkCXvx2QeOgmshdVf2xMo2IEqY2XiG4VrPUionAB98BNP+O IQ8vooDdxqIEE86nBOGzlzpY9oIa6mR1xt/piGzlbgccMz1O7nQcJMnkY5k6381f/VCTY pFjPrtC+el414NyTiT9mtBrxU6DkRJIc6D5jHS9nnXdJ0ISudlSozk92TRKoEi7sVcdOr ZHaKshtJkdsGBTyRq7YyjAXXG+Y4sIi2zxUo1N0KvzEVdurvbevze+XPz6UdQzmSEYQ== ARC-Authentication-Results: i=2; smtp.subspace.kernel.org; dmarc=pass header.from=nvidia.com; spf=fail smtp.mailfrom=nvidia.com; dkim=pass header.d=Nvidia.com header.i=@Nvidia.com header.a=rsa-sha256 header.s=selector2 header.b=DuUyw8yv; arc=pass header.oldest-pass=0 smtp.remote-ip=40.107.201.46 Received: from CH4PR04CU002.outbound.protection.outlook.com (mail-northcentralusazon11013046.outbound.protection.outlook.com [40.107.201.46]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (secp384r1) server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CF340606A31E; Mon, 26 Oct 2026 02:51:26 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org CF340606A31E Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=nvidia.com Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=nvidia.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=Nvidia.com header.i=@Nvidia.com header.a=rsa-sha256 header.s=selector2 header.b=DuUyw8yv ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=uLhPOmKK2pFh6taEYCBp8CK0feicZ7JlcI3SAcPjUiZ3hWjzOkdzEmaTzpOkyu3Sa7WcXcyRRKXzEZ3cYN51NKgsymmn/qjTpb5aqP3DDeNBsgjuYsjU4Yt7Jzi1+gjokSn5iz13yEIvbvhiKrGI7spiu94DVIAlmCDkbuKZ6CTSVgJHR27OvAE0XKD1Dg1IwPKijiBonbkIpVa1UObbPPHuiyFnVM4iLrPRo7O7OfNyzgSmJ31nXUIlgNSZG31fvJ+gNuxX3NOB4R3hgreUPn3GV34KVsFXr/RMPIOdQbStWIyOwStq7fcVIdFbebmoOY7wAJ6E5OVJAcK4eOh00g== 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=G6OsTiixpt5M1jc2jalslJkV4KaBfj1Z1QWDgxtaVRk=; b=UaD+feoDSRNARHxbxBhLVtsJGfHVc8NY2IMPFBHnx4h7RMMoJ7NDBdM1Zsx6q3o+pVn9lHMZdTWPYPltjlBh/2UJo45eRPeKG9TEGHVtxjLYJV/ynoCIaHNmpl2Wlp+0cgz232bwIxM79d09vlmhp1RT9FAXg0VzqO2EofkPrenfpT5EPGGXRApa3lTsA3934k9q2EiGifQeyT0lsku1IMpJdcCcjmr5qrZ+2cz1e+dCxQp08gnyk8YU3y3DTtJjPzShRUbTtTK5i/Um9D2tmvvJe1co0pQ32WkzQVG9bF9/fuxAuEZpZIad+wUqaAzseUSAq6yw3gWKweocc+nU6w== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=nvidia.com; dmarc=pass action=none header.from=nvidia.com; dkim=pass header.d=nvidia.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=Nvidia.com; s=selector2; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=G6OsTiixpt5M1jc2jalslJkV4KaBfj1Z1QWDgxtaVRk=; b=DuUyw8yv0+5if86sHxruuu4tlL5u4V8B3TR72BaNHQIPD3/ASZT/xdI6O4LKBHupqWqR4F+lymkWuMvEbC2ldmHqH51u64tTe8FNJGMuP2KrfghABjmZqe+3C8t1Ew7TmSLAem0ZOW7obwOwbhPfAH9ZPNtwkc9nEtHRp+i2dpI3ppvf0asKLAqW2CvnG2ey4gp5GxlygMh4XVSfn6yciEhXhC53NX+dxZsGMkCZHkswc1RCIi6trBugrYCgDp4W7EfAoEO5oecBGlNGFWFfRm2biiXld4USdD30M1EhlIfhvJiXcvkfY0G2hZ5FxMo+khhGOcn5d5Iz0F3bNUjvdg== Authentication-Results: mx.microsoft.com 1; dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=nvidia.com; Received: from CH3PR12MB9730.namprd12.prod.outlook.com (2603:10b6:610:253::9) by DM6PR12MB4483.namprd12.prod.outlook.com (2603:10b6:5:2a2::22) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.21.546.22; Mon, 26 Oct 2026 02:51:21 +0000 Received: from CH3PR12MB9730.namprd12.prod.outlook.com ([fe80::843d:c1f0:b2ed:4128]) by CH3PR12MB9730.namprd12.prod.outlook.com ([fe80::843d:c1f0:b2ed:4128%4]) with mapi id 15.21.0546.021; Mon, 26 Oct 2026 02:51:21 +0000 Date: Mon, 26 Oct 2026 13:51:16 +1100 From: Balbir Singh To: Gregory Price Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel-team@meta.com, akpm@linux-foundation.org, kasong@tencent.com, qi.zheng@linux.dev, shakeel.butt@linux.dev, baohua@kernel.org, axelrasmussen@google.com, yuanchu@google.com, weixugc@google.com, baoquan.he@linux.dev, baolin.wang@linux.alibaba.com, hannes@cmpxchg.org, david@kernel.org, mhocko@kernel.org, ljs@kernel.org, dave@stgolabs.net, roman.gushchin@linux.dev, stable@vger.kernel.org Subject: Re: [PATCH] mm/vmscan: reclaim every zone in per-node proactive reclaim Message-ID: References: <20261019185002.3428594-1-gourry@gourry.net> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-ClientProxiedBy: MEWPR01CA0269.ausprd01.prod.outlook.com (2603:10c6:220:1ed::7) To CH3PR12MB9730.namprd12.prod.outlook.com (2603:10b6:610:253::9) X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: CH3PR12MB9730:EE_|DM6PR12MB4483:EE_ X-MS-Office365-Filtering-Correlation-Id: 31d70899-23c5-4e52-ceab-08df330c041e X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|7416014|23010399003|366016|1800799024|4143699003|11063799006|56012099006|261022105027099003|10067099003|22082099003|18002099003|3023799007; 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:CH3PR12MB9730.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(376014)(7416014)(23010399003)(366016)(1800799024)(4143699003)(11063799006)(56012099006)(261022105027099003)(10067099003)(22082099003)(18002099003)(3023799007);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?Gv8wOjyvcmsYlIGzLYb9/MmEBHkzaxevBVQxDFVE6Gb/p6uysy+Y5vpIEOTj?= =?us-ascii?Q?LScn0EmyyBwmb76Zz7+q7ODIXLjN9eTDLyXZalolJak+JR6WmmOjMSUedwIW?= =?us-ascii?Q?49WUr980xh3YibgSeK8re4yi0BT/0UNRzTivwrA2lfeWtgLbeufJ+EgUJw/r?= =?us-ascii?Q?HqmJSEeMv1LazCGBni1ceKeqSzohf5gs6Q2iny8z0+O+4IsJwwsjXc38OkOx?= =?us-ascii?Q?ZRp3NuTbxGJAj9+VOi1qV7i1yjmenG01fydxOQjW8wHb/2R+8e5b57h1rjV6?= =?us-ascii?Q?O5oqq03s1iu55oahLSeNLur8GNxQnYNtkE4Mwzh1j4BHQaDYRQwVcVAtw6gV?= =?us-ascii?Q?H/JPx5mjNZyXuGNo/InAJ4L7Ywoh3qxDGj2ekjoLPJr+cTz1ocYSg+78yj4v?= =?us-ascii?Q?qEMnRnh30947smLDqSghNY2S3H/tjhL15oxVdQdvfZqm8xKIezVwJu2jgFW/?= =?us-ascii?Q?XRhgqTicsaLTaI0k22t286doSmNOSpM8nxt+Nth7vIW+v24iXwolWnrJdkXV?= =?us-ascii?Q?GrBRwnxLlV86kVmKc7HvwXvjCZGCdbLreMx0Miarr+nspaGQYKXwAzJuhC/A?= =?us-ascii?Q?ziafET382902TpZnZMG55ntZYS5FIYrcSreuF9jqvlsbLRBt7+35OU5uI2R+?= =?us-ascii?Q?GUAhH8/9BJy35Nta6txAKT5ygKkvewGuqqj+c3bbzMv5rg990jJkmflIPHDo?= =?us-ascii?Q?H7AWNYHxhWEqowlriweXfcA09YR6UxPtlwRzKhYftU8+j4AOT02tK6SPPAUg?= =?us-ascii?Q?TDPJOSfPWHGf7qvFSZqmyO/jpB84J+avzk/bp6Pps2/m0FmbS1Jqo6sfFLuf?= =?us-ascii?Q?Jp0GN+pIal7znVdH3rXdElWpAv/VZQp3mIMoheSVefBcVXN9Hs8xDjSp1/0a?= =?us-ascii?Q?YHXNsDzPu2ZSoymPg3dxCM3lJT2rw8sirGk0XAtMbDtRaws2Mfioc28h/sKd?= =?us-ascii?Q?K6voxTlprJk1E9M4VZ4f0n7kqC1hQ8FGCUFk1LeB57bWc63SaP4Llr5rpY4z?= =?us-ascii?Q?8Llm5tyNEjYozrPm5kI7ZBrDS+SePJuXlrKRjU2EA+vF0nL2fatPdhvLCSUr?= =?us-ascii?Q?+jwg2J0vddVSl8XTRboLWQ/QBp5HCgx/9sL52/1xU9UoeTHJrlr9L7KBo4Xc?= =?us-ascii?Q?HA4gF7psnAJo4LbCXwbQD1407d0M46ncW+SSaufNLH3SYlWotiMvHvHjbZq3?= =?us-ascii?Q?0hQQXIInfPJ+W1EsXw8o/XUnRpsWWAmAlMeCFedFECY9Ap9h1KNtzQUpPj9Y?= =?us-ascii?Q?9MNBJhvmfC5f+pQIRkTQ2r7PkzoDdHcMFEQr8AjZ78Cft6dS/ROlNaBlydHc?= =?us-ascii?Q?BGjnxQSZ3lrEmIM/7EqcKV02KJKUpVaqtJUYKbGBeVYtO6mshZfIKqklLX/k?= =?us-ascii?Q?C/4B81I0NCeCu5VmM3jkqItcRtYY77Iib+QRjY+4wOFnFWAO/7AaT+0ynStE?= =?us-ascii?Q?envcWY5spC1XgwaC9BG3jRv7uIqCy/c+WaCtrmpSZe7BJRozsCB/4ATIiCH5?= =?us-ascii?Q?q1/c4dbM4P5EJhGDpT+4nropSRtvE43Z/bg48h5UuNSyyZll8OdiGO9pMC02?= =?us-ascii?Q?NnZslnby33HV6bXGXCOQrKITc4+Nupc4ekIaZl4ehfCDBqOo3CAmEqVPgysc?= =?us-ascii?Q?7HLeKexfTTERBLK4cNEvACtdVV9OL1CnFUYN3tNOEKyng2gDJeOfwT6Te0e7?= =?us-ascii?Q?qxsIWn0gwhJXaaggD/3NupCQaz3qEwb+E0dmkoHqXTII7l7Bs/Dy9Fvxdwdl?= =?us-ascii?Q?iMb8g94RpQ=3D=3D?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 31d70899-23c5-4e52-ceab-08df330c041e X-MS-Exchange-CrossTenant-AuthSource: CH3PR12MB9730.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 26 Oct 2026 02:51:21.5647 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: aJQMiPXki5ufOJ/+QQYlxSKDB4ARNumN6QoZOJfihiQHteO/v2PCpQEuMXIcHa0jjdgeSTTxjMMgB4PMEuKZEA== X-MS-Exchange-Transport-CrossTenantHeadersStamped: DM6PR12MB4483 On Mon, Oct 19, 2026 at 11:04:12PM -0400, Gregory Price wrote: > On Tue, Oct 20, 2026 at 12:49:37PM +1100, Balbir Singh wrote: > > > diff --git a/mm/vmscan.c b/mm/vmscan.c > > > index e82ba737c028d..90f7a7bf4e426 100644 > > > --- a/mm/vmscan.c > > > +++ b/mm/vmscan.c > > > @@ -8180,7 +8180,7 @@ int user_proactive_reclaim(char *buf, > > > } else { > > > struct scan_control sc = { > > > .gfp_mask = current_gfp_context(gfp_mask), > > > - .reclaim_idx = gfp_zone(gfp_mask), > > > + .reclaim_idx = MAX_NR_ZONES - 1, > > > .proactive_swappiness = swappiness == -1 ? NULL : &swappiness, > > > .priority = DEF_PRIORITY, > > > .may_writepage = 1, > > > > > > I just noticed some other issues with this code, in terms of honouring > > zone_reclaim_node (not related to this patch). I'll send out fixes, for > > this patch. > > I'm shocked, I tell you, shocked! > > These are all things I accidentally ran into by just uh... using the > interface. I'm absolutely positive these interfaces are full of bugs. > :) I was looking at making may_writepage and may_unmap align with the constraints of node zone reclaim, .may_writepage = !!(node_reclaim_mode & RECLAIM_WRITE), and .may_unmap = !!(node_reclaim_mode & RECLAIM_UNMAP), which may violate the contract for proactive reclaim. Proactive reclaim itself tries to be compatible with cgroups reclaim interface, so it sets these values to 1. I still feel it is a violation of default node reclaim parameters, but not sure if it needs to be fixed up. Balbir