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 CF8CACAC59A for ; Wed, 17 Sep 2025 13:08:11 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 210268E000E; Wed, 17 Sep 2025 09:08:11 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 1C3D88E0007; Wed, 17 Sep 2025 09:08:11 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0394C8E000E; Wed, 17 Sep 2025 09:08:10 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id E1AA98E0007 for ; Wed, 17 Sep 2025 09:08:10 -0400 (EDT) Received: from smtpin04.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 9572C160208 for ; Wed, 17 Sep 2025 13:08:10 +0000 (UTC) X-FDA: 83898770340.04.F4055D7 Received: from mx0b-00069f02.pphosted.com (mx0b-00069f02.pphosted.com [205.220.177.32]) by imf26.hostedemail.com (Postfix) with ESMTP id 36D4714000E for ; Wed, 17 Sep 2025 13:08:07 +0000 (UTC) Authentication-Results: imf26.hostedemail.com; dkim=pass header.d=oracle.com header.s=corp-2025-04-25 header.b=sHIT6M0W; dkim=pass header.d=oracle.onmicrosoft.com header.s=selector2-oracle-onmicrosoft-com header.b=JA2rRbTW; arc=pass ("microsoft.com:s=arcselector10001:i=1"); spf=pass (imf26.hostedemail.com: domain of harry.yoo@oracle.com designates 205.220.177.32 as permitted sender) smtp.mailfrom=harry.yoo@oracle.com; dmarc=pass (policy=reject) header.from=oracle.com ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1758114487; 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: in-reply-to:in-reply-to:references:references:dkim-signature; bh=DQmFTMEv9tSVcNtNln94icseigbNju0MH1d/wELuGqo=; b=yKmboL2zbudkNQqcmLDpgu85cXk/KSMwuz7ziiXdbrSeopoxIep+mmMyo89RDAwegI62tr tqDnxM6He/NQ7KuhlxxqucQTHpnmQlM1QhbtkH3MNkb9SXjvwIs+FGB8bL+zv8AK2SKLyQ YayDKF0HMnP+brPkuNwVwNMnSxNxQPE= ARC-Seal: i=2; s=arc-20220608; d=hostedemail.com; t=1758114487; a=rsa-sha256; cv=pass; b=oTCgn5Up6x5jf2QRSvoOOmydgdvSpc2Zk2GRkcFfdbxYxXKpg9wr9Xad+XSbi1n0mIcBee Tx76kePQQDfjuLxL2j9lppewv9SepW+VqQVTLNBjrjaXuHOxUMkYr0c5/VcDuBYq/4zaI/ pO5Q9Bd6VDx6J6Wa8r3vx+p+ffnUFEE= ARC-Authentication-Results: i=2; imf26.hostedemail.com; dkim=pass header.d=oracle.com header.s=corp-2025-04-25 header.b=sHIT6M0W; dkim=pass header.d=oracle.onmicrosoft.com header.s=selector2-oracle-onmicrosoft-com header.b=JA2rRbTW; arc=pass ("microsoft.com:s=arcselector10001:i=1"); spf=pass (imf26.hostedemail.com: domain of harry.yoo@oracle.com designates 205.220.177.32 as permitted sender) smtp.mailfrom=harry.yoo@oracle.com; dmarc=pass (policy=reject) header.from=oracle.com Received: from pps.filterd (m0246632.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 58HAQfxQ008301; Wed, 17 Sep 2025 13:08:00 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=cc :content-type:date:from:in-reply-to:message-id:mime-version :references:subject:to; s=corp-2025-04-25; bh=DQmFTMEv9tSVcNtNln 94icseigbNju0MH1d/wELuGqo=; b=sHIT6M0WxBpTnMO4DynVoLBGR6YeAKqL3u 9oRXZTrPa2sVZf0V2CNAREFmLrz1Y7Rz5znb9A7RhVfuyLF/PcFOOdw91b14PX1S Npfp25SGtHVmP4RkW/GROXhfYsIr8feJ9UspaBsZGF7UUN6p02I983NiuADcmjd9 Iahtn4Xh9sFdU6m6o17lXa9OSTfkP7nzWsxPmknE7zPZKqDFUgerzqRUVETdgAVx Jzg1QL1UmkWsJSrMTX8N2jj75Ym0CLjAgxIH9/X/keEUlUNlrEZsuY2/yXBQaJr6 0Oo4ZIKva33IDDRb3APGusHiGaXTb1pG8au+0LBblHDL+rP3AGcA== Received: from phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com (phxpaimrmta03.appoci.oracle.com [138.1.37.129]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 497fx9157m-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 17 Sep 2025 13:08:00 +0000 (GMT) Received: from pps.filterd (phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com [127.0.0.1]) by phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com (8.18.1.2/8.18.1.2) with ESMTP id 58HBnuVV033752; Wed, 17 Sep 2025 13:07:55 GMT Received: from mw6pr02cu001.outbound.protection.outlook.com (mail-westus2azon11012059.outbound.protection.outlook.com [52.101.48.59]) by phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com (PPS) with ESMTPS id 494y2dqhnq-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 17 Sep 2025 13:07:55 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=CQAHfEvPUeKgfMXYb/mFoKQz/8rMla7C3iDLgsN9gPXWqJZ7PJf+ry0uEDBhABg9aMb/Yuu6MVldjdHBwn9L10zvt4WFVhdNQhp4Rz8uz2hPNevWM+b2g0D55YbvOPultYbh+24t54xQvcSR7jfmJQPBGpuG2tcLMXkaMuGgW8rTsLXiOLLMr51eQCg7s1obaGnbL53qrSV5DUdMXBTLvdhlxo7f8Ca5qrtjVSzXcAyJXv0ioMdpCxbB5j/eMMljPTXWFSJcYyHK3siXXza52BjF5D4k22kNthByyLvhTgYnBRlRntJXXhQXE8wZL5v3UdWMRKzXepyU1obm5t+kiA== 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=DQmFTMEv9tSVcNtNln94icseigbNju0MH1d/wELuGqo=; b=NzCRvtU0eJqPHWpSD3V95H3FzcAXQoYxz8kU5qnBAZvm3FhS+ntPn2at9fhzj8OVdJcSpE4ChUjLkWmlEN72uITNL96zJimUf1g5k/llvmtb93q4PZylwyayhegfGjpwxyqOfFXlKyFrRCLGbFtZZuclAg3P/hGD0ni4krPYmuS+KndJqAMLo4yzVxyUO52DMKqm6O6grfHNSqjtbj23RMk8Ng1EmOZBrvluIgU8a5hL+P+EoIxvfdqpzLkMOCY799FsSGAkjCvIUHUPdGAKSL4qKHh1YkS8dWEDoHxHKig1e+cGwVxnbnZ8sJvqhD74UhnFy6xR5hSCpU0K3ddqqQ== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=oracle.com; dmarc=pass action=none header.from=oracle.com; dkim=pass header.d=oracle.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.onmicrosoft.com; s=selector2-oracle-onmicrosoft-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=DQmFTMEv9tSVcNtNln94icseigbNju0MH1d/wELuGqo=; b=JA2rRbTWMh0Z7CxqNEY4daANOKOSYDiZKizLMA7Xb/eCYhsfnaFqC2DM/McUVzzciYjRTXq1a7OouHwlxjri60p3rfWD2gUsNnU1qoxbEAkVHWUaLFiIUfiKUfw8Qwmh5H9D1cWgTUWpjjVaYrqH7ttoVYqFA/o7lUcY1Xbrd8g= Received: from CH3PR10MB7329.namprd10.prod.outlook.com (2603:10b6:610:12c::16) by SJ5PPFDEBD75B51.namprd10.prod.outlook.com (2603:10b6:a0f:fc02::7d7) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9115.19; Wed, 17 Sep 2025 13:07:52 +0000 Received: from CH3PR10MB7329.namprd10.prod.outlook.com ([fe80::f238:6143:104c:da23]) by CH3PR10MB7329.namprd10.prod.outlook.com ([fe80::f238:6143:104c:da23%7]) with mapi id 15.20.9115.018; Wed, 17 Sep 2025 13:07:52 +0000 Date: Wed, 17 Sep 2025 22:07:43 +0900 From: Harry Yoo To: Vlastimil Babka Cc: Suren Baghdasaryan , "Liam R. Howlett" , Christoph Lameter , David Rientjes , Roman Gushchin , Uladzislau Rezki , Sidhartha Kumar , linux-mm@kvack.org, linux-kernel@vger.kernel.org, rcu@vger.kernel.org, maple-tree@lists.infradead.org, "Paul E . McKenney" Subject: Re: [PATCH v8 04/23] slab: add sheaf support for batching kfree_rcu() operations Message-ID: References: <20250910-slub-percpu-caches-v8-0-ca3099d8352c@suse.cz> <20250910-slub-percpu-caches-v8-4-ca3099d8352c@suse.cz> <6f92eca3-863e-4b77-b2df-dc2752c0ff4e@suse.cz> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <6f92eca3-863e-4b77-b2df-dc2752c0ff4e@suse.cz> X-ClientProxiedBy: SEWP216CA0137.KORP216.PROD.OUTLOOK.COM (2603:1096:101:2c0::6) To CH3PR10MB7329.namprd10.prod.outlook.com (2603:10b6:610:12c::16) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: CH3PR10MB7329:EE_|SJ5PPFDEBD75B51:EE_ X-MS-Office365-Filtering-Correlation-Id: 0abe08bd-3d13-482a-9b41-08ddf5eb3554 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|366016|1800799024|376014|7416014; X-Microsoft-Antispam-Message-Info: =?us-ascii?Q?MP/QRk2CA/g92A7eIaqH7W+nzGF6DLxtU3bWhWWVGwaVYgBj9IOes1Ys20gB?= =?us-ascii?Q?+U9fgj7OMY8toz1gFjBIhegToUSpSF4f2sOxjsowW5Mgv6UqBUCTawm8FbPl?= =?us-ascii?Q?dXs5ANOubzjRRYTjlmVYIy6tcrDT2segaNPVeUav7hZ8De/FmuUOALgSREmy?= =?us-ascii?Q?4bvECNHj4g0A99VxxUoM7udNzkJwQZ00AKhNwUgGFsGuHy6bWsBi6vz2q4fw?= =?us-ascii?Q?qeIGPN2kzr2RJ8euOE+qRuRBqXTyD7aZLVPWhFnANnlH+bIwXy3D6P4qDbV9?= =?us-ascii?Q?1zTe+j2gPu9cxN575qoMXYrx9MdyX/WVdAw7cxlziu0veXRPZ4BQh9yCuowE?= =?us-ascii?Q?TS388KNmIe2R78YUakAO0Jrm6U3ecpBFaUt4OiUtShsrT52h7wyDDo1m+TRo?= =?us-ascii?Q?v4QSGP06yMlC6x0glYsJG9ks8OV/2zle+AMk94/0uZ9twZCBC8xc47ll5tl0?= =?us-ascii?Q?uWIQWuAr56D+VFlzziREE2nwO9qB72y6Hy+mS2xUT/nn8pi09gNv0q4wJUnl?= =?us-ascii?Q?uA6AHVFvDZ7plAzUL+7hwAxUNcuBDl3XkJHZxIgyj55Fj5iU1g2qiM8bHDac?= =?us-ascii?Q?uFPtDoaEcKvqxtI/Ch6spCpQ+x0umWFrWM3eed3Gr8lrAMTQTsAZe+HtQmN6?= =?us-ascii?Q?CYvSv/YydQXKgSbL2UCk6A+Z8baNsHG7gyNVRl2cKqDBWsf4mdFz/OTSikag?= =?us-ascii?Q?i7Iyw8SFXLUSNF6u8vF3nr9LzpJvgxEnljrT3RSAqJJ2sZDLhkx5b4HhEr8q?= =?us-ascii?Q?hrxHCvT0Jk6zqlUX3kRlejx4hpqAPPgcktUrYYICA4Ha/F0AOZGgYbjqcKGu?= =?us-ascii?Q?SSjnw8h5ecpX4ZRf4goqhlOMi+AItOGDITpo5eXWZ0SnMP6Kf+F/KNUDLajt?= =?us-ascii?Q?bC3r4gd35K3bQNCZgagRGh6z4K9tGAI8lhEkONfxlc4EIS+ygybhXIcQdJmu?= =?us-ascii?Q?D+92WRBikoAi2pAppg1fpdYHZBzYYuXeO92S/G0jQ6HvTzdbNc0XiBKaThoQ?= =?us-ascii?Q?6QO6S2WsYyAcurGglgwmeAceD/mYjoDLUR7ukjzx7OlXp+fomYasjtQZjrHS?= =?us-ascii?Q?RPECL7LqRg+yOPoKptUcMPa2p079KKlCFkMGs8UL6K/YzzmrPxxfrmtubr17?= =?us-ascii?Q?4TlfoGQDaIShMEhTom2b0JR17ufyNOIV0z8aDeyQ+hulcNUw7Yrlevo15Ys6?= =?us-ascii?Q?DBDyEYhovG7zdg7dDX0rU/RkxW3g0XaLUmxx8Fblzso1qA0PzkF9iFgZkCZ9?= =?us-ascii?Q?zurwve4/PJyB87KoFdFwJH5FS1N3bOygqv87tcPF+nbAbb+SNKFqmaxjoich?= =?us-ascii?Q?JwTCd+m2lJEw+asXNv895h9oBlgkIv192tkrOYxv+xAxByjaD1CjHxmDYXaj?= =?us-ascii?Q?+GTX8xSTw/12sIq7XiPrg3P8qFqQsnRpCtX3FDLalQEYltU11Gy9vEIEYddH?= =?us-ascii?Q?9Q14i7JibQE=3D?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:CH3PR10MB7329.namprd10.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(366016)(1800799024)(376014)(7416014);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?UYfNqqBtJDjNYFDTl6qx06AXoI878dGjN1VCjpGviNstzjA1EjxCUIq8RgqR?= =?us-ascii?Q?+SzQjrT/Bdphcgv+wRQAG2XZ/Qyt7TiVjQs0t7KbBob5/uQ6vceSV2XWtZrY?= =?us-ascii?Q?AL3O44nqlxUtj/tUik0GNBrRuxQVGXLverh62n01AED88SnbnLFkLlZcwSI2?= =?us-ascii?Q?bSIW62hUwoFhVWdtkagq7KL/YOwrIsv+JkHB5ZPNva48PnTRdSPH8NXO225Q?= =?us-ascii?Q?YXS19cvpOYLGJ0bJ68LRLO3bJIr3C4yp6Dplael/6nbMCkZtNupVGP6Zo2Qn?= =?us-ascii?Q?vX2lxUZiULj62D/H5TcxbUT2RERhZk4xqQ0rH/vYhMQGdlsgAPhs95fwyOKZ?= =?us-ascii?Q?VU55fBur6ySJiFri4tkFnrDMQnerPPPqTo2U399Qush8659BI3GkUCI2ivqc?= =?us-ascii?Q?I4UL0Zl6Qh3jV+g7oj0BE8larTExnSXH87vT4ZIviJq4Nzlp44y5iHQPBMF1?= =?us-ascii?Q?t2FxvvjVjON6Ad4hAbayUwUWvH3qqJZ6Ek6/3IFQAWq4Qrmuas/nuhLR1UzQ?= =?us-ascii?Q?SoQae0nYlX2FIEZALZI8rz5bKFORJjYXNMNsRRAS44h/2A3gPflA+a0Td5Mw?= =?us-ascii?Q?4d5hjuaR03MS80H26xjUMlf2UfCEXvAm3xF6BVwKnEELzWOqzWmbMBasB2+Q?= =?us-ascii?Q?bJGCksnpXiOsqR4VtfYgcodddw2hAW6WPR2vo1ScLj83gMVTFTdTKOUXaI3w?= =?us-ascii?Q?1fqIBC3v9w9hwjOaluMQurkgRILtmqL2RFi5Mq2lfcF1l0p7eXoFRSUc8TRL?= =?us-ascii?Q?OLUn6fV5ZGc3LzRT4SjORP/KQUHhy/6b1Mpracczoglvxjq87vGH7kMUw1Ch?= =?us-ascii?Q?e6b6x55NqRi3/Msp1JCMhJ3Jdn0kN/X6HJWRf4Myz1PWBBxhufYtWeV/VuvC?= =?us-ascii?Q?e88VV0haTy9/tAgZuCeMeW1SwN9H9SsZ1gHFnErrs7sn3oxqCJ/V2vebxRTv?= =?us-ascii?Q?IsyWUEJiEc2OvD1hQJsGHNTyKCDA6Xfuu4pBVNfZl28Atq0MyHMK2ukZZDn4?= =?us-ascii?Q?Kfp23U8yWt9CbSa9C5q2TswjENM+2Vxr06drQRvhlTnYOLgeLdyeOQ2yw1Ks?= =?us-ascii?Q?dKTZn9QBehssq3iVhFYxh5YK+qJTg00po1d7cJCXgA2FG8bOScduEi4j9zYD?= =?us-ascii?Q?BVsnBKDd5HUZM8aqMx9cHC4fuRz8qBcTlOu1FPtMs5cRgY/T9NCzlyWMmNr1?= =?us-ascii?Q?yChnrzANk8eNbLHsE0Y1+HCUTkTBJbpH+66+MeMbcUrzxBsHjUym3M3o/gA8?= =?us-ascii?Q?IvihXgI6Xfj7p78uxKGV/mf7UAG5morYrWF4ChcDBHS6xU9R1k9u34bOb1AV?= =?us-ascii?Q?3krHo5YxXIMQ7ghw7XNik4OomD0vFq7eYaAEbagqD5dPxYRAJgpqQoQJYgxA?= =?us-ascii?Q?nvLX+pMSYkpTNBU6GZNcPjijkj11YD+uQD7BT/jy9EdMkpvnCQi7ysOhpqyn?= =?us-ascii?Q?LJpue7g+chDr7jEIn7hobgnF9HNd39BhDvmKTr905ffjawynzpsiCYI/Hi7O?= =?us-ascii?Q?je2c3/i2qeP8n1KR5XI5sd1XfUtpI/g4bHLeoW5Jufc15Qz+qS9LMX2imrep?= =?us-ascii?Q?jUmiDoelo/L4U432LoUPZv+trT2nsdQYQNk/5IKa?= X-MS-Exchange-AntiSpam-ExternalHop-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-ExternalHop-MessageData-0: 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 X-OriginatorOrg: oracle.com X-MS-Exchange-CrossTenant-Network-Message-Id: 0abe08bd-3d13-482a-9b41-08ddf5eb3554 X-MS-Exchange-CrossTenant-AuthSource: CH3PR10MB7329.namprd10.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 17 Sep 2025 13:07:52.0878 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 4e2c6054-71cb-48f1-bd6c-3a9705aca71b X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: p0kKL/z3x4T2Oavn26kgqYNfiC6Qfc/bE11dzz6A3TiAT0cwgBYdW6yZX3lXx2RpS2mjChxtEtZA4+uCYaztqQ== X-MS-Exchange-Transport-CrossTenantHeadersStamped: SJ5PPFDEBD75B51 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1117,Hydra:6.1.9,FMLib:17.12.80.40 definitions=2025-09-17_01,2025-09-17_02,2025-03-28_01 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 phishscore=0 bulkscore=0 adultscore=0 mlxlogscore=999 spamscore=0 mlxscore=0 suspectscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2508110000 definitions=main-2509170127 X-Proofpoint-ORIG-GUID: 1eEKXK4faAkWkvIdmbbrOPapFUofqNKd X-Proofpoint-GUID: 1eEKXK4faAkWkvIdmbbrOPapFUofqNKd X-Proofpoint-Spam-Details-Enc: AW1haW4tMjUwOTE2MDIwMiBTYWx0ZWRfX9kEViy3CGIMI LGstSPJsZZaOAVQs88GzHRh3mXLQbDSOgJYZe8oTOr68W/lZBbA6r2rF1ah/mc0R5ez11/wSd9E RA4tKIBqt9g6OL9O8yrBjXaZSjG44kbclDduN6Buc0svbmukeH2Zx+odce/Roq03JsySFqF6Ldk MQWfzaX81Eae1Fc7DAhl8ii5fho/xhNA2IrVixFVopk2cJxB17o9UuKJt/uT5xGLhlmSTYQ2c3b crWF3iwWRi1fONhHf5LGjCkazgduyTQhB5PHXhbJXptOQ49O3Y5HYE6Z1Zs+AgJ4pS68nVyBsgk u+dBB9A/rPPeQHH/zxgGjLPQBI8l5GTu5kQkI+OIFZdEU76ASP5mfvtHz/TXar/+uL1m70i4N6Z mMD7zI9z X-Authority-Analysis: v=2.4 cv=N/QpF39B c=1 sm=1 tr=0 ts=68cab2b0 b=1 cx=c_pps a=WeWmnZmh0fydH62SvGsd2A==:117 a=WeWmnZmh0fydH62SvGsd2A==:17 a=6eWqkTHjU83fiwn7nKZWdM+Sl24=:19 a=z/mQ4Ysz8XfWz/Q5cLBRGdckG28=:19 a=lCpzRmAYbLLaTzLvsPZ7Mbvzbb8=:19 a=wKuvFiaSGQ0qltdbU6+NXLB8nM8=:19 a=Ol13hO9ccFRV9qXi2t6ftBPywas=:19 a=xqWC_Br6kY4A:10 a=kj9zAlcOel0A:10 a=yJojWOMRYYMA:10 a=GoEa3M9JfhUA:10 a=oFNO0EsnXWWuSgokDikA:9 a=CjuIK1q_8ugA:10 X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: 36D4714000E X-Stat-Signature: yjqj4dsq3poqpearw5f91bi8zuys8n1e X-Rspam-User: X-HE-Tag: 1758114487-251275 X-HE-Meta: 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 DKRoTkWT 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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 Wed, Sep 17, 2025 at 02:05:49PM +0200, Vlastimil Babka wrote: > On 9/17/25 13:32, Harry Yoo wrote: > > On Wed, Sep 17, 2025 at 11:55:10AM +0200, Vlastimil Babka wrote: > >> On 9/17/25 10:30, Harry Yoo wrote: > >> > On Wed, Sep 10, 2025 at 10:01:06AM +0200, Vlastimil Babka wrote: > >> >> + sfw->skip = true; > >> >> + continue; > >> >> + } > >> >> > >> >> + INIT_WORK(&sfw->work, flush_rcu_sheaf); > >> >> + sfw->skip = false; > >> >> + sfw->s = s; > >> >> + queue_work_on(cpu, flushwq, &sfw->work); > >> >> + flushed = true; > >> >> + } > >> >> + > >> >> + for_each_online_cpu(cpu) { > >> >> + sfw = &per_cpu(slub_flush, cpu); > >> >> + if (sfw->skip) > >> >> + continue; > >> >> + flush_work(&sfw->work); > >> >> + } > >> >> + > >> >> + mutex_unlock(&flush_lock); > >> >> + } > >> >> + > >> >> + mutex_unlock(&slab_mutex); > >> >> + cpus_read_unlock(); > >> >> + > >> >> + if (flushed) > >> >> + rcu_barrier(); > >> > > >> > I think we need to call rcu_barrier() even if flushed == false? > >> > > >> > Maybe a kvfree_rcu()'d object was already waiting for the rcu callback to > >> > be processed before flush_all_rcu_sheaves() is called, and > >> > in flush_all_rcu_sheaves() we skipped all (cache, cpu) pairs, > >> > so flushed == false but the rcu callback isn't processed yet > >> > by the end of the function? > >> > > >> > That sounds like a very unlikely to happen in a realistic scenario, > >> > but still possible... > >> > >> Yes also good point, will flush unconditionally. > >> > >> Maybe in __kfree_rcu_sheaf() I should also move the call_rcu(...) before > >> local_unlock(). > >> > >> So we don't end up seeing a NULL pcs->rcu_free in > >> flush_all_rcu_sheaves() because __kfree_rcu_sheaf() already set it to NULL, > >> but didn't yet do the call_rcu() as it got preempted after local_unlock(). > > > > Makes sense to me. Wait, I'm confused. I think the caller of kvfree_rcu_barrier() should make sure that it's invoked only after a kvfree_rcu(X, rhs) call has returned, if the caller expects the object X to be freed before kvfree_rcu_barrier() returns? IOW if flush_all_rcu_sheaves() is called while __kfree_rcu_sheaf(s, X) was running on another CPU, we don't have to guarantee that flush_all_rcu_sheaves() returns after the object X is freed? > >> But then rcu_barrier() itself probably won't mean we make sure such cpus > >> finished the local_locked section, if we didn't queue work on them. So maybe > >> we need synchronize_rcu()? So... we don't need a synchronize_rcu() then? Or my brain started malfunctioning again :D -- Cheers, Harry / Hyeonggon