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]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 0B466CA1013 for ; Fri, 5 Sep 2025 22:42:25 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 34C548E0007; Fri, 5 Sep 2025 18:42:24 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 2F76F8E0001; Fri, 5 Sep 2025 18:42:24 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 1E6098E0007; Fri, 5 Sep 2025 18:42:24 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 0D4228E0001 for ; Fri, 5 Sep 2025 18:42:24 -0400 (EDT) Received: from smtpin14.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 9FC82C02F2 for ; Fri, 5 Sep 2025 22:42:23 +0000 (UTC) X-FDA: 83856671766.14.65E4059 Received: from NAM12-DM6-obe.outbound.protection.outlook.com (mail-dm6nam12on2053.outbound.protection.outlook.com [40.107.243.53]) by imf06.hostedemail.com (Postfix) with ESMTP id B780218000A for ; Fri, 5 Sep 2025 22:42:20 +0000 (UTC) Authentication-Results: imf06.hostedemail.com; dkim=pass header.d=Nvidia.com header.s=selector2 header.b=rgXg0qC1; dmarc=pass (policy=reject) header.from=nvidia.com; spf=pass (imf06.hostedemail.com: domain of vdumitrescu@nvidia.com designates 40.107.243.53 as permitted sender) smtp.mailfrom=vdumitrescu@nvidia.com; arc=pass ("microsoft.com:s=arcselector10001:i=1") ARC-Seal: i=2; s=arc-20220608; d=hostedemail.com; t=1757112141; a=rsa-sha256; cv=pass; b=VbWCQTYY8fpO8ooedoVhm2YK3NtKb0JQ/L+6PNKBMqhTJlibQZNGjEsdbSq0DQWF80PoV4 ZYauWh4KQnA6ZRpIUvNvzAnVYeTWj0jvSZuGZ3bfeNqcNP4m3HNtVD6yNG1YWz1D6TxbS5 Sb7XHEnsEyXM3kLKWnv+FoeoJxTBGkY= ARC-Authentication-Results: i=2; imf06.hostedemail.com; dkim=pass header.d=Nvidia.com header.s=selector2 header.b=rgXg0qC1; dmarc=pass (policy=reject) header.from=nvidia.com; spf=pass (imf06.hostedemail.com: domain of vdumitrescu@nvidia.com designates 40.107.243.53 as permitted sender) smtp.mailfrom=vdumitrescu@nvidia.com; arc=pass ("microsoft.com:s=arcselector10001:i=1") ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1757112140; 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: references:dkim-signature; bh=vU/bebcp3HREI3sP9u0d7XhT++cBICW1iGA0162/QV0=; b=tR+XFZXAXGoeQKRQaRcTM/MkycmMAhB+i4PHXpGZNWGXuIDRMLxahHAZ0+E6Qpbp7By5vr T7P3sEUqdp/pCqFTq9MiPE57cCk1hdoHV/ZUZzAYnQ07sQFN1yxZczeNMBKR04fs1w1tRj 5nIO6xeQ2qvb8nLb3hxmgxGyBjzahME= ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=GomhA9+J7LM5J8v9A0UhMl9BnFLrCqLrONxeEFmfGZKYF+q6tebE8ivslqV/eKBPIhx28oPkMaE6OUiLPoOA6FNzOS+RrlRzm+Q/U9c3q//TAqYjrr4nm5wymVpGVWk3ylFaUu4Eo0NsICH11faxvIVPzJDgnB1e/FhpwsV8mXlAAq8ymkiTUilB6TdzKSxYPwbttem1eGqlqmKXc0bMkSMD9Up2mscZt9b1JUGBoX3dAdKn3Hs63AL8mun8eFFybyk26Jn5UHB3YwWxLjwSTiuKI9urjbCoF6JXdVP+kAzni2YM9UcJ6fVSw6EWedbXJ3j0vSdNUsTfmgPrYcFhXQ== 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=vU/bebcp3HREI3sP9u0d7XhT++cBICW1iGA0162/QV0=; b=aypz1LDpSa+u3E6F5zRUk6BX95jvJWtyNlOv8xE7LaJSgJcOyrAR6Ln+bGKYnJarXl4u0Tculex9pKJiFvFqCcZ1eB8aO9M559P4cUoQUq0OVdg4naL/q3GduOL39dmFCv0vFiGhJ1LpAcwylv+fuQhSaLLQ5MBNRjuf2XFo5FMcVz/V4uvCS5/Gfcg/nBQj6RadkGsAk0W87JrvgOSswxDzii4WwE9WUmdZEjtJGd4Yj+KiLF6RYxaYxg3W026xSHV+BCBAaDSvbrV13IdZv6U5vTPYrrPnxyHcLhDQoNYKjTdXc0CBJG0zyAnd8rLn1NdTLZRMjJ9hq6FBJPgvZw== 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=vU/bebcp3HREI3sP9u0d7XhT++cBICW1iGA0162/QV0=; b=rgXg0qC1ftmaAnQj7teRqtfTqF8VENkHT3kiL4gcHSXCHddttYQ2GzqB2z5CL92AbhssenJaDbwODTBMN+YG27ujpK3AuPfpVX6j6/gL2x/WCgBJihnFe9tcjYCuVm99Emm8DWv+Yxrqcq0EW+hZe369gPBoBQee2wzCOmT27wY9nNTg1Y6KttdgzECZxAKagJGVKh1Dt/GOYUYOjKE4JbJS+CkuPo2jVl4jQaeCrK3vGpzdLlClCpfkOQGEeZhYmgzLT3mWWmeIlBP/Uj3hwosYtL0kfYPiJ1/gvH5dh4gOCeKczCtg0ASviWVWctZ1ebYhWwaZlCVGr59uewqsQQ== Received: from BL1PR12MB5205.namprd12.prod.outlook.com (2603:10b6:208:308::17) by IA1PR12MB7685.namprd12.prod.outlook.com (2603:10b6:208:423::21) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9073.27; Fri, 5 Sep 2025 22:42:17 +0000 Received: from BL1PR12MB5205.namprd12.prod.outlook.com ([fe80::604c:d57f:52e0:73fe]) by BL1PR12MB5205.namprd12.prod.outlook.com ([fe80::604c:d57f:52e0:73fe%4]) with mapi id 15.20.9094.018; Fri, 5 Sep 2025 22:42:17 +0000 Message-ID: Date: Fri, 5 Sep 2025 15:42:14 -0700 User-Agent: Mozilla Thunderbird From: Vlad Dumitrescu Subject: [PATCH v2] percpu: fix race on alloc failed warning limit To: Dennis Zhou , Tejun Heo , Christoph Lameter , Baoquan He Cc: Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org Content-Language: en-US Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-ClientProxiedBy: SJ0PR13CA0014.namprd13.prod.outlook.com (2603:10b6:a03:2c0::19) To BL1PR12MB5205.namprd12.prod.outlook.com (2603:10b6:208:308::17) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: BL1PR12MB5205:EE_|IA1PR12MB7685:EE_ X-MS-Office365-Filtering-Correlation-Id: babcdc8b-6787-483a-1373-08ddeccd7723 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|366016|1800799024|376014; X-Microsoft-Antispam-Message-Info: =?utf-8?B?Z3ZTamx1TVpXcE1GK3gvNzlaK0pycTQyM1hQU1lXVFQzMXhEUGZXaUpDQW9Q?= =?utf-8?B?djlhblVNeStrUWk5UEttMFhZaEVBQmRtMGFjeEtrcUtHU1VaazY0MENnZmlZ?= =?utf-8?B?R3RCejltSkxNVWVNN3hQTmdqdC9YbFJWLzhFejhsUnA1MVpwODZSTGZBZXNZ?= =?utf-8?B?Z3lvbzYzN1lxaVRaWnhRNUVORXJybXp4eUg4YTVNNVJjaUt0eERldkkvK2ZK?= =?utf-8?B?UGRDN2ZuYTJXZ01PRmZmMmdGeVRQMy9ObFNqdTExaWNkMzlOV1doM1FQZjdi?= =?utf-8?B?aW1oUFNlclBxd0JCV0hMR2M2RHl0V3MrbUQ2WmtydlBJQS9mRGlYYU5oRStt?= =?utf-8?B?TG12UlJORTRFVWJ6M1RNVVdBVnZqeTIreUp0dURJbVdGZ2JvNGlmR0d0dGxs?= =?utf-8?B?bFRLVHJFTDVKOEppRk9CdWNsYkVmRlBkTjJSN0xpUmhmSDBDZTlleHhwSkho?= =?utf-8?B?UXprRFpHWmlkVEdYNXdjWW9TcGxkcGZBd3ZWV0FsbFN3R2N5K25HZk40Q2RU?= =?utf-8?B?Qy9nOGE4S1VYVER4OTV3Z0s2QmpXWXk5eHRCWGdENFBiRWNOZkN5TTljWU5N?= =?utf-8?B?YWNNeVFsc2hYWGFOOFZteUkrWVAweTZvUTdzalhJenVBVGhiZENKWWNla1JL?= =?utf-8?B?bm0xdmNlTTZPWE1Na2VHTlEvV2NuQktyMFhrNVJ3anRUY1NrTTFRbkVSbFp4?= =?utf-8?B?aDVOUkE1M3JMRFhqWGlyUm40a3B1QXlkOWJDL0pkU2Q2YjJKWnhWaWpYOTFu?= =?utf-8?B?TDVxOWhiVWxSSkFMSmsyZVBWcDJtTDZTa1U0QnRsL25zODVEYXJxcHZDcGFk?= =?utf-8?B?a1RxaDlYeWtkWkJMSXRQQ0tESjA2aUQ3aUhiZ3BjVG00OC9TWVcySjdUSkRP?= =?utf-8?B?YVVhKy9tWUxINFZwdVFzbU9PZDU5L003eFBYRVMySlJPbENoNXpWVnhZK0JS?= =?utf-8?B?Y21hd0Zxd0wxMU5IRU1CNWxzVnZOWEFjNDVla3R1Z3lHQ1pRQTg1SEdOT0lx?= =?utf-8?B?WjJLYXR5OGR1dVFKWlp2UGxWVmJKZitFWWtJL2NHcHNJa0dkTGNtTFRhdGxq?= =?utf-8?B?dElQNnprOWgxM3dnQVVtVWh3cjI2NFBRSWw0ZmZVNUF0eGlLWlpMSWpEK2lF?= =?utf-8?B?bFgzeld3ZEZBbjgxMmtNRG8yK0hsVEM4bU9JRVJtU3VXa3ZLZjEwbDJxMHZW?= =?utf-8?B?MkpYRFM1RWYwNTVGZlp3Sy9adDRIaW03bXVGeG1CZnk1d2hjVnVGOGJnOFBh?= =?utf-8?B?RllLMDVCWFlJeUgxZGIrYTlSbHkzakpwZFVHSWNwS09ncDBwak5nOTNOUUgz?= =?utf-8?B?U3ZYdjE1L0V2VjB5d1dTT0x3RkEvMFlHaWRqTU42Ulo3UlJEaTMwcWpqandC?= =?utf-8?B?TUNDWVZsVjhTbDlNVnR5Mk5zcnFaeS9Sb0pxR2Q5ZW1NWlhsT0MxVUZZbEZU?= =?utf-8?B?d3RqbDg4M0FQdTdjU3ZTZDlLakFwaEdhMGRyZENMdlgxL2ZGM3NXcHIwWlpl?= =?utf-8?B?NUFqYmEwMENOTjBDZFl0Zkp5N3dqRGliZXBGa3JnU2h6VVlwTC80UkVaUkR4?= =?utf-8?B?eG1ob2U5VG9Ha0x5MnhWWU9MRTd1c2NqeGtyQ2NoaytUdVpjS2xWS0ZnNHBL?= =?utf-8?B?NFBSWWNkMDVOSVNhRDRscUU2aTlndjVpMC9ERnRWcDRRWDBIMDZxRHh3SGRW?= =?utf-8?B?ZytiSjB6SkNrZW5tejFnZGdzK0k0NUM0Y1NMK3hzemVyWVpjT3pTTEZOKyt2?= =?utf-8?B?L3pLMWdKdzhzNG9YcEJualVWQnZPWE82NDh0dlFYTlQ1UStGdzdnL0VHMTE0?= =?utf-8?B?RnJ5NDZMeENlSnorOXV1azhaQUJCSWY3ZHBOMVFtNTJudG1pS2VVOTVmRWJa?= =?utf-8?B?V1dRU1ZDNHRub0I1QjZoMERMQWkrdXBhYUp0ajlPTW1Wbnh2dHE4SVV0V0hj?= =?utf-8?Q?tOXxaiNFJHM=3D?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:BL1PR12MB5205.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(366016)(1800799024)(376014);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?bXluSy9TdXlRcGRiV3dZeHF2aThZRjhNemZlRDNhVGlWRTJIL2NERjJwdjc3?= =?utf-8?B?ZzI0R1FWL1lDa0RSVUF1WWNHVHhEYW85LzRIenZVYjVSWWxLMzNLQzFkUVA2?= =?utf-8?B?YVNuRWdWNFpNNDgxVUhHMVhRUTVMTlFwWWJOMGpmdDRlWkE5RmYxajM1V1Rz?= =?utf-8?B?MndpRWYyeitDZTJ5U3AwSHVEY2ZReUFHcWl6SFFIeU1GMjRCVit4KzRVMElC?= =?utf-8?B?ZWVlZkFXOUNoREdhb2I0dEdHeDBxVkwyYzdnMnNrQnNIK0ovcnQrcG9jUkhZ?= =?utf-8?B?N2ZoRjN4YmI4WW1va3lVaGtoL2xmbFVSOHMrU2dYUlFHWk01WHR1dk9WODZK?= =?utf-8?B?UHBBbWRLakJDMUc1cjJqNVJoeWJXN1BWSzVqQ3pCd0laSjRHdlM3T0lSeDFN?= =?utf-8?B?Y241OUVhZlZOaGpkT2tBTHRPZks0S29CTHBaV0wzMkoxNk9PUmVxZVh4U0ZP?= =?utf-8?B?UWN3ZmZPL010MWY3T01QSE9waUtHdTFrdDhoLzREV1crR0NXUHB0bnBWQlhi?= =?utf-8?B?WklBdVc3anRLZUNFRU9VcG4renNWSXU0Ymh5U3poYi9wMzExSW5zcC80QjhC?= =?utf-8?B?VWFkS1J3TGNuR2JSTjVRUHBGby82cjZFdEFmb0lHWXpWOVE4aW1kb0FWMUVE?= =?utf-8?B?SWZwY3JPMGdLNE8rN3NoYmsxd0I3ZkZaeFJyQXordUlXdEYrMmp1b01FQlhD?= =?utf-8?B?N05ERXZlQlROc0duNXd2QmNkYmNRMGM4U0FNZnJhNVZUT3BvSitDZEZnaEc4?= =?utf-8?B?bHQ5QVM5Rk10bUR1UW0zQ29qT0dJOUQ4dEQ1aHpiWk1Pd0RkcjJVVVVHVnZi?= =?utf-8?B?UUNNTjJmSFBBalhJWHhUSnlFTXhNMEt2bmNhakwvS2tmY2MrQ3dqTXYyN3Y3?= =?utf-8?B?ZStvNG1ZNXR3ajRzUzZDdzZVaFA5Z3RoNWhPVmxUMHNkUW9zcUxVUnlhN21B?= =?utf-8?B?VXRpdW5oaXF1ZEZDN2hkZ215bi9abTN0T0V0SEx4VzVadFF2aGt4aHZ0TWJ5?= =?utf-8?B?VFN1R0Z2TkZhV2laWWxoa1BmTUFuT0xGd3lBUDVWZ2ZZdE5XVUNuSmluSi9L?= =?utf-8?B?UG1NMnhwNEVRL2pNRHBEOWxmKzBIVVRNMTRYY3FoM1dvS040alBtZUVCcFZq?= =?utf-8?B?Yi9hcFgxZ1ZxcXhWaVRFd29JTWF2TlFZc3RWNzBPTHBjN1I0RzAyVXJVRW10?= =?utf-8?B?Q1ZqamZxbkJCbm1UYmF4RVpLSWQwRG1NK2ZzdCs0SHRFRjcrRmpFMXdyNXdn?= =?utf-8?B?U3ZYQ2k0ZzJaQWlhRUYwVmYzQUtHZVQ5ZlByeGt2ODV1by9MU3M5VXc5WHdP?= =?utf-8?B?Wkc3RytMbThMdVZyRVJzS0E0SkI4STFaVDJWNVk5dXNKYkttS2x4ZGx4c1lJ?= =?utf-8?B?di9tSXpCL0VGaWdXQWFnNTEyZHJucld0eUhsOEM2MlNuaDExY1d4OVhSRUlO?= =?utf-8?B?ZEdTaXRRS3llOFdOOEU1KzdxRHRneEpXS2JYMHZXdENJWWgyNGpLSmh6U2hJ?= =?utf-8?B?aHl6YVEvUmp0RHBrakxOQnJWZFA1bjQ3M0RxYlVJWDBqZW9xdjJaYjd0ZDhF?= =?utf-8?B?YjQ5Um1HTGFzQzIydVkzRi9wSXpldklZRXpDOTdlY05tMEYycjdSSFhib0Jn?= =?utf-8?B?dDFUMmRWNWtCTlpONE4rS0dEUTZ5d1Qwck1oNFBRd0lpMTI2NU01bk9uTHd0?= =?utf-8?B?eUo1SDVZRlJCU3BoOVFzc3dteGk3VzVUczBseitSTGJ1QUhKemI3SjViMVBT?= =?utf-8?B?MDh0Mmt6ZTRQeXg3TktFcG1peE5vSVArczZPTklMYTNUblF1OFdHVnQrMTln?= =?utf-8?B?aUE5RWNrTEJVWDBXRTNEdzFIWElFaWVSRDF1d0NEMzlmbVlZK0VQMkx6OCtx?= =?utf-8?B?MjlhcDBGYjhnRlUxbFp0L0ZBV1RBN2drTEQ3c0JCenhacUI0Z0k4cnVQby9a?= =?utf-8?B?L01GUkZDU0hqbmNNODh6ZHM4cUhScUU4L3RlY0UxNDBkZjNWc05FQmZQbkxu?= =?utf-8?B?S1IzUXlYNjlTa3F6YzZDQzFvV0d1QzV4TTgzSkd0R2s4WlRLSjNobGZuaXVB?= =?utf-8?B?SlZ5YmFUS3YrQ2ZFNTEwZVBPU05qRGR2Nlg2S3M3M0c3OFVsbkg0ZjdRZGxm?= =?utf-8?B?TVlGaUh5dHd6bStoTjVzYzhiS1pySmFuaTdyZmZmZ2dLUVBqZFFBSkNlazZj?= =?utf-8?B?NGc9PQ==?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: babcdc8b-6787-483a-1373-08ddeccd7723 X-MS-Exchange-CrossTenant-AuthSource: BL1PR12MB5205.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 05 Sep 2025 22:42:16.9502 (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: VJdW4QaLpdVowfPkvEG0DtHEKuJ1Ue2WxawBN+MOM4G2GlF1cvHBTpA8LDK+Twxjz97n5hkaoyo1cIot5t9Ikw== X-MS-Exchange-Transport-CrossTenantHeadersStamped: IA1PR12MB7685 X-Rspamd-Queue-Id: B780218000A X-Stat-Signature: 59ec84ood5o87icjtw6bwoecxbk7d53r X-Rspam-User: X-Rspamd-Server: rspam06 X-HE-Tag: 1757112140-295218 X-HE-Meta: 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 ErPdKqGF 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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: The 'allocation failed, ...' warning messages can cause unlimited log spam, contrary to the implementation's intent. The warn_limit variable is accessed without synchronization. If more than threads enter the warning path at the same time, the variable will get decremented past 0. Once it becomes negative, the non-zero check will always return true leading to unlimited log spam. Use atomic operation to access warn_limit and change condition to test for non-negative (>= 0) - atomic_dec_if_positive will return -1 once warn_limit becomes 0. Continue to print disable message alongside the last warning. While the change cited in Fixes is only adjacent, the warning limit implementation was correct before it. Only non-atomic allocations were considered for warnings, and those happened to hold pcpu_alloc_mutex while accessing warn_limit. Fixes: f7d77dfc91f7 ("mm/percpu.c: print error message too if atomic alloc failed") Signed-off-by: Vlad Dumitrescu --- v2 changes: * prevent warn_limit from going negative, as suggested by Christoph Lameter v1: https://lore.kernel.org/linux-mm/ab22061a-a62f-4429-945b-744e5cc4ba35@nvidia.com/ mm/percpu.c | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-) diff --git a/mm/percpu.c b/mm/percpu.c index a56f35dcc417..81462ce5866e 100644 --- a/mm/percpu.c +++ b/mm/percpu.c @@ -1734,7 +1734,7 @@ void __percpu *pcpu_alloc_noprof(size_t size, size_t align, bool reserved, bool is_atomic; bool do_warn; struct obj_cgroup *objcg = NULL; - static int warn_limit = 10; + static atomic_t warn_limit = ATOMIC_INIT(10); struct pcpu_chunk *chunk, *next; const char *err; int slot, off, cpu, ret; @@ -1904,13 +1904,17 @@ void __percpu *pcpu_alloc_noprof(size_t size, size_t align, bool reserved, fail: trace_percpu_alloc_percpu_fail(reserved, is_atomic, size, align); - if (do_warn && warn_limit) { - pr_warn("allocation failed, size=%zu align=%zu atomic=%d, %s\n", - size, align, is_atomic, err); - if (!is_atomic) - dump_stack(); - if (!--warn_limit) - pr_info("limit reached, disable warning\n"); + if (do_warn) { + int remaining = atomic_dec_if_positive(&warn_limit); + + if (remaining >= 0) { + pr_warn("allocation failed, size=%zu align=%zu atomic=%d, %s\n", + size, align, is_atomic, err); + if (!is_atomic) + dump_stack(); + if (remaining == 0) + pr_info("limit reached, disable warning\n"); + } } if (is_atomic) { -- 2.49.0