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 D2B7BD1268C for ; Wed, 3 Dec 2025 02:18:36 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 004D56B0027; Tue, 2 Dec 2025 21:18:36 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id F1F426B0028; Tue, 2 Dec 2025 21:18:35 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E0E376B0029; Tue, 2 Dec 2025 21:18:35 -0500 (EST) 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 CE16B6B0027 for ; Tue, 2 Dec 2025 21:18:35 -0500 (EST) Received: from smtpin01.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 6B2AA14040B for ; Wed, 3 Dec 2025 02:18:35 +0000 (UTC) X-FDA: 84176550990.01.581074B Received: from mx0b-00069f02.pphosted.com (mx0b-00069f02.pphosted.com [205.220.177.32]) by imf07.hostedemail.com (Postfix) with ESMTP id 0B8284000B for ; Wed, 3 Dec 2025 02:18:31 +0000 (UTC) Authentication-Results: imf07.hostedemail.com; dkim=pass header.d=oracle.com header.s=corp-2025-04-25 header.b=dr9TuaoH; dkim=pass header.d=oracle.onmicrosoft.com header.s=selector2-oracle-onmicrosoft-com header.b=E9pteehz; arc=pass ("microsoft.com:s=arcselector10001:i=1"); spf=pass (imf07.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=1764728312; 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=pRP95LEuFnmkb4Sxs2HnYG+9fnk3G31Hg3wO9rwvWq8=; b=DMGUirGEFOLa54sSIImueS+7xCQZ3fR77Cfv3KRti74T9tLUmgAO2Afu5Nc8af+zEKhspq HzGB8yTqDnjtoHYikZ4Sso/F2cSWYJgnUW41j5TmjDNuYXhU3BnYUbgtUaspynMzf1ps9k 79vlfbPL8yz4Ehx9njmHtw8ZstKUbTc= ARC-Authentication-Results: i=2; imf07.hostedemail.com; dkim=pass header.d=oracle.com header.s=corp-2025-04-25 header.b=dr9TuaoH; dkim=pass header.d=oracle.onmicrosoft.com header.s=selector2-oracle-onmicrosoft-com header.b=E9pteehz; arc=pass ("microsoft.com:s=arcselector10001:i=1"); spf=pass (imf07.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-Seal: i=2; s=arc-20220608; d=hostedemail.com; t=1764728312; a=rsa-sha256; cv=pass; b=CWp1SkL9r1+x0YH4OzGR6WR3VehWHLFiUyU9J3aAEgGgcP6mQIrT2a8/FxsKiakxJbWdD3 JTJTJ1102eAeJk5Vld787qdgmysoiYfGrMHxkGnbPZu3mCslWM7U/4gCnOIQEIWABTetNg MyBio3KEwjM3Ho2EsYu0tTfm03eDbU0= Received: from pps.filterd (m0246631.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.18.1.11/8.18.1.11) with ESMTP id 5B31NdrV1570511; Wed, 3 Dec 2025 02:18:22 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=pRP95LEuFnmkb4Sxs2 HnYG+9fnk3G31Hg3wO9rwvWq8=; b=dr9TuaoHQN6zrQzftQxb7lmG5cpFgs6ybo XwHBXEijas2WlVD/UNvyx5l0wJig9A6sAxxwUd13NLBh4KwTQAHPeJq8rgRzTVqd eMEntMoh1dZRoRIUVjn19M8NykyxxmFN+eTi5iWk9ci4PqzlP5Qhkqm9ehqKFxHO qHmFpJ0w+3CsGGNSVd+YfjLWQEsDK8WGKBMQibknqrQSTn347Vm0ygPSa1uhEqpO D+oKUHr6Rk/ilbQOOt0FYNY8G55AkXBaG2Ri+h0BS48K5vgFDF87JZ68gN+bDOeT u5ltI4zS/OHh7r4mmMci4b/IJw7gZu6PfFCwf0tN5k/Vrzwe0wJQ== Received: from phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com (phxpaimrmta03.appoci.oracle.com [138.1.37.129]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 4as7u7vdhc-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 03 Dec 2025 02:18:21 +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 5B2N4fh9015054; Wed, 3 Dec 2025 02:18:20 GMT Received: from mw6pr02cu001.outbound.protection.outlook.com (mail-westus2azon11012049.outbound.protection.outlook.com [52.101.48.49]) by phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com (PPS) with ESMTPS id 4aqq9a47ed-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 03 Dec 2025 02:18:20 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=gNgZOe7+xpjwUaK5yA8+1QlnJ7f/foEGJLtiy+ydVZTzX14FqvV18640IIXjS6g8vhTX+m9U1K0FYKxPfEJd0qQhDtSmDGD26q8DEA66Udyv/Se/MBdXpBhZibD0Gx6AKBEpDOE5x3kLT480gOkZ02fz4zQrxX3hn4FTQifFPfqwxhR3WS14XMVldCGppSqj8Ey4z3pIqYIJ72fDViRjqQELbOW90a//YK9e/CFdUwdIihLnUTXD/xTt5JMAzsRu31aHVnHH4ON+1TkhMJglnft7c9k9S1rvXecyO4p5vsFLxjm99ADqd8pE8D3ticdv/8cZ5onkNHmLYmLxOkMtkQ== 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=pRP95LEuFnmkb4Sxs2HnYG+9fnk3G31Hg3wO9rwvWq8=; b=PtBS3IT0gprWemEpwfQ1r1BZpb59UAtoijdvZWfbY8pj+ddtTE7wgVAG5tbclFqClONqEbFta8bvOyiK628zUU75IzsTSgGsqZrEl5BlWlf2lAnCQXi2RsKD0n42Dq+/cRRHRXWYwOL+C1IN9p0Qd2//NelwqPRNV6IiFJkUkgLPW+PfUAJqje3VqbeiKagTyfGd3RLN7ctdDiAkMfFjG4DoUPDx7nbrZCZESLxp/Mng0fzLxU/cgVNHVI8YhYpTLkJgCnE9wwM6rNqLq41AehIL0ahYcvIEH4x4F/TTid8Cd1T3s+6nZ8rhlPPRfmmbCAlVhdRi0AdSMKuTJe94fw== 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=pRP95LEuFnmkb4Sxs2HnYG+9fnk3G31Hg3wO9rwvWq8=; b=E9pteehzarlNPzY596naU9R3H9FYUf8hND7u20411aAWxA2lKDg+ezNzGWdr/kBonzb8nhHYLCh7r1/JVFLB0ENsNssItSCPuDG0hQz16yK6ECHkzDwZiZ3Mwy5Nd8eKu9JnBY6sGG4vH25zRxn/Y8o2dLgzrBu+IGATujb+AnA= Received: from CH3PR10MB7329.namprd10.prod.outlook.com (2603:10b6:610:12c::16) by CO1PR10MB4609.namprd10.prod.outlook.com (2603:10b6:303:91::6) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9366.17; Wed, 3 Dec 2025 02:18:08 +0000 Received: from CH3PR10MB7329.namprd10.prod.outlook.com ([fe80::c2a4:fdda:f0c2:6f71]) by CH3PR10MB7329.namprd10.prod.outlook.com ([fe80::c2a4:fdda:f0c2:6f71%6]) with mapi id 15.20.9366.012; Wed, 3 Dec 2025 02:18:08 +0000 Date: Wed, 3 Dec 2025 11:17:56 +0900 From: Harry Yoo To: vbabka@suse.cz Cc: surenb@google.com, Liam.Howlett@oracle.com, cl@gentwo.org, rientjes@google.com, roman.gushchin@linux.dev, urezki@gmail.com, sidhartha.kumar@oracle.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, rcu@vger.kernel.org, maple-tree@lists.infradead.org, linux-modules@vger.kernel.org, mcgrof@kernel.org, petr.pavlu@suse.com, samitolvanen@google.com, atomlin@atomlin.com, lucas.demarchi@intel.com, akpm@linux-foundation.org, jonathanh@nvidia.com, stable@vger.kernel.org, Daniel Gomez Subject: Re: [PATCH V2] mm/slab: introduce kvfree_rcu_barrier_on_cache() for cache destruction Message-ID: References: <20251202101626.783736-1-harry.yoo@oracle.com> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20251202101626.783736-1-harry.yoo@oracle.com> X-ClientProxiedBy: SE2P216CA0029.KORP216.PROD.OUTLOOK.COM (2603:1096:101:114::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_|CO1PR10MB4609:EE_ X-MS-Office365-Filtering-Correlation-Id: 504592b9-30cb-440d-c40e-08de321232e9 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|7416014|376014|1800799024|366016; X-Microsoft-Antispam-Message-Info: =?us-ascii?Q?sqDS+PyI6QkkeVcsltZ4rZSFNW7fc7dkhRKYyq1WU878F2dU5SdJfcwpBi2w?= =?us-ascii?Q?ZVWWcsedgbXxd/AmihzGZVGHUDGghttDu0uL1r4yAzz6+9TgNCRYdSL0cZks?= =?us-ascii?Q?IbHq9wcDsvFPDpiNZo6e0Upjv9CGslbFCGRpHarMELt65lSZWWlxEYYhKlQs?= =?us-ascii?Q?rvLv5BzrKttYuya11DJn173IBzKDtcHp4zQziPMGzy0e5Kpea4sl0e9XK6iu?= =?us-ascii?Q?/hzy13bMmVtwqUIRXRuC0590y1lLdEC/hj0E5C85COQWwihxwPc1M89u8CCG?= =?us-ascii?Q?aP7WBP9IlmSqJNta4a0IDH39/rFt6Ib23kk/LF8pSm9umcHiKeG7dbOBHz2V?= =?us-ascii?Q?wMZ9n145wXz1FcaepaqBf7tvRxM8/ChSiTrqZqwkOUducrgCZOXrtk4YQs+X?= =?us-ascii?Q?I0scnM9JnRm1kVGvvLqZEu76yieJq3qD7GqP0GD3SdlV2oXnmhWa5el3Cdpx?= =?us-ascii?Q?IBLDXCAKg6+/CYDME3JtywyX8wyc+Fx2fg6udgU8IJjgRmfoQkLuWs5PmP6N?= =?us-ascii?Q?WsBike/MUUZDpsQP/N+TjJnQBMuxApudcRtwDU4csKRwHYSGMD4WT0NjYsKR?= =?us-ascii?Q?CFufaZ1U9epPaEN8G0I4WBOmpszXOgbzHGCvoojeCRR/V/n1xc/P9AtmnE7G?= =?us-ascii?Q?mcg/2B7GbZLMw9pT1Z1yMA3XAToLkXjHf0oPpO2FszUruFdshfQFHAzzYbIr?= =?us-ascii?Q?E1vpBG6DOVR5BXKZ8pPhqJjMVoIPgUpfaYO3u542GOqST1oH0ylZ+XdTayCn?= =?us-ascii?Q?Gmic/T+TSsP6O66DygaonINY8StajeHfradvHgTbNqa9vz/t0VVJKJUAlS3/?= =?us-ascii?Q?KQ2nNa7DpjvMUu0Vlic/JWfhE9EvRhzn3WDAxV/410xnrytzT4fZKLbY/NBm?= =?us-ascii?Q?08vpbBvZtxYbpXOLRLZAHW/tyfCt9O1RHd+EA6oMWYwo8DEZyHkGtXekEhTo?= =?us-ascii?Q?3v0l8pNBOc4ixzIdeHzS0D/2JMfyBBoxbkMS6YpIwIZNsZPTBhZEKaNq6Yzy?= =?us-ascii?Q?M8jOOTF04ix8CRraqVXht6RiH9NW/GmZpe8qAZIkJvLUNtS4e7Yhb/pDqQlq?= =?us-ascii?Q?ijZUN3T/y+vs1Fyi2cVImCOEwXlOMXgkZNFfCUhlzZG+hWDrgq18M2FPUmlp?= =?us-ascii?Q?jLoPc5NrhvINC0eiBbOEBJ56kq0qic2R3uev5aPl9MGAqEwiLV/MItgzFGnf?= =?us-ascii?Q?UUrkoRz464uXPdzDHEib80MLodH+IfhFW8jokMC2NYvRaY/puE6JP6HeRnFX?= =?us-ascii?Q?WJqw+FbehvQXge3xuGIxDcZanhGw4c39qLZNtGAfo2CIJR2OcEyYvy0vewFi?= =?us-ascii?Q?osos4BlnSYHE44CVAYmrG3woIq+bLBmIwOCeAv0gSpWJ4zrn5F7BhLoAbhxT?= =?us-ascii?Q?9yGDCjFNcROz563RJho8TXSNhEiVmlh6EKzH5cKO4c6otxC1YpZjt5Wu4ccN?= =?us-ascii?Q?5oBxFWKi+ffqwvv85qhsPg0qlp5oAFma0Fl8HTZLGttHic+fL5LpCg=3D=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)(7416014)(376014)(1800799024)(366016);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?rubGdEUzPHDfTA4ZKI1t71I31jP6srxfrwFxUF6Sy7hW4sOolHkdSHPj5TE1?= =?us-ascii?Q?n4PWytJ4idYozYPmCCGLLFSV133T83Wg51BsrGgobSG6CLNCFZ0Yg6oCETu0?= =?us-ascii?Q?dqFzNJtO6UQDl7JDO4pHY/AcFzbOMO0VCVTyQakE/q2EudCcsbfFqcz0Ftew?= =?us-ascii?Q?uNxEN/EjO9dNPKu6BNYhpqisEEa2rYqFYRgaBAqdWfZBqN8dfuDd9MjvO9kE?= =?us-ascii?Q?s7v1XLJ3aGDk1n66A9tFfZ2BRhBdz70aLi2eQgIEbUCAC90L88xUa+VlxTbw?= =?us-ascii?Q?fijuRyeGAwcJAugmNoVLC1GkmRajutjcnfR+IOaCvi74s4A7GHnHe2WA8m/Y?= =?us-ascii?Q?tQ6/ltyjERzXmFgupMr22AWEFKp0WU8mbV6TgnvkiZH/itQM5oMPJhFP3eg2?= =?us-ascii?Q?A5ZSMQa9eW/IohwgQcdgJEFAHXj5n4WZE+KIZTJPCdrkAigySrVSYeLSX9lq?= =?us-ascii?Q?QMKEds5JRs87ub7SuqnR3Z1tkZz4OomwTeLaZfGbIXkcvA1hBpfqwlIIMB/T?= =?us-ascii?Q?m+EtE9Oljkk3hJaJdtQ0h+ieYtXOUpzcJ/E7suEHekhyG4l+C7BkK6qZuzSl?= =?us-ascii?Q?BeQuy2dhustOihxTknK96kxciAy0D+ExaIwEkSqrf4y78hYbyjViGETle4lB?= =?us-ascii?Q?bKDSj+vqmzRkN5uQ1wvnphhcXgrHh0ci0yeVrBtWLuxgZClTI8x3BW0yHaQt?= =?us-ascii?Q?tcN1VduTf2focY0HFoEfnFwb9vg5DBAyletfpLwciMPld3pQCGbz3etntBxc?= =?us-ascii?Q?QwNqQCsdB0A2+w0SaEJW9/GnnDcySHLDGCAF03uivHZXQL/A61e7y1vBdD0O?= =?us-ascii?Q?yTOqYciBfu/wZXuxJjxEluISqhp7dCrZicJ7IXlBt1VKHE9be0G+u4WIJQxD?= =?us-ascii?Q?+PsAOGAdvUDu1o9y6YHT1yO+xRoCNrT8yOR6ddQNFSCTYbnsVq+TadoZz+G8?= =?us-ascii?Q?bVmZRYTWrLHZMDsjq6MbIPG0QRJUfFncdiSgGOJmGfPdUsCAth4Sr9FDVHg7?= =?us-ascii?Q?2pb/hqiLoDPqasqkiDl6IJh8dxRRRPmOC+xPHt8uy4j/0EHxwlXXBSGRw8bZ?= =?us-ascii?Q?Aa4cImyqyacYsS4F7uPTjHfe0maz857igO0pR+43trfE/sw45r3IULkm+H5u?= =?us-ascii?Q?ZGjR+0OYsQeJpVs2XVbmvLnvhVds7QsTKxTNExRFpUNfqhDUJlDXWJ5PjyP3?= =?us-ascii?Q?dvJWz00riO1TzaILjIPcUNm8i7/d+zXsDwlKJnFsQKX2sidVmYuaeV76O6Hk?= =?us-ascii?Q?7DAJbXfAOBMoNrIgWqQ4vUpdpsug6UmLuj1llakbsjZ2v9E0w41C5aIDLyzQ?= =?us-ascii?Q?t9jM2z0gllgZm9xFzUYMABjpL83jrZx2l28tSwn0cqIqilC7Xn65l3532cIA?= =?us-ascii?Q?NzAx05M0LU5VjiEUES9uYFBo/JgyT0/NldNG/+X5zwaDRzYcVpiik91yExzj?= =?us-ascii?Q?EhqeVbsxSlMZVT8Mr8OJfU8l+4PbCw9ILtKk53uBv3yKvzAffZN5qpqZXl5m?= =?us-ascii?Q?MkjtsZA2g6CkqREV9A8tUwH8+/XjKGE7Q4ih5lbAXdI7BabNr+8dulHXgnck?= =?us-ascii?Q?v7AkZeCycLbSvFn+iGFAR1a+/9HcSE30gOgI5Nzh?= X-MS-Exchange-AntiSpam-ExternalHop-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-ExternalHop-MessageData-0: X2gPyAU2deaSvM3R7cV7tCwZoSvn4dkBTOJ1SHV7YPTRzKufvTfD6fvv+14Ydr4Bnp3CanIL/ZFKpmdl8izjn+f8aNnEUaA9mNSTtaChQaCrvfiJ7Vqeom8DllEyZuwmsTemkt8ukPYnEclFnrNuAfNSCs1n3j1NTZUKH4j191vE8hb7hD0YG1DVmT7031HtsCspnNajaJrUsrXrivo5avQ57BAp+YWkr/lnUxD40t2QT0nNX1HydsPzXEJ5Bs1EkV/mPYZOlTXEkMGKV6qq9ednmCFciysDRmL/BIlZFsvHzN4x8k/xWl/b2ksYrot5GgYZhEykwP5JGp01FGyYA/c8uYJynEs4MHMw1fKN0n8bW2fXXR8XbZB0bAYlPwdGoPz8j0PjRiNYLUA9AoGCYhbDzU1PvzJBI7w9TcvlxnUavNQVz88KK2wBIJhCygMsMdl3dgBmkJTPzdA9BZ2QDMhmrBtqppKjPuhy1OQxk2G9y4e8M5DvaisY13u2i2DWJ/brLHsmzB4xZle3RwzzZaVXO+9U3LRoQXj2yPpjvw8c0fFer76cgAnBNnnVk8h3Yy8Dr20HaJ8e3B1/ipE9Sg8XZkLO9lRMoEZxXUBF/i4= X-OriginatorOrg: oracle.com X-MS-Exchange-CrossTenant-Network-Message-Id: 504592b9-30cb-440d-c40e-08de321232e9 X-MS-Exchange-CrossTenant-AuthSource: CH3PR10MB7329.namprd10.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 03 Dec 2025 02:18:08.2455 (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: 85uIHmK/yjB6pUt9tyPsJhC+Zo+Z7TNFcmN65yFe1pYeQ4nyjHTwCnlADD7PpcJoc0QzS88DPkAXCvnr8V1nlQ== X-MS-Exchange-Transport-CrossTenantHeadersStamped: CO1PR10MB4609 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1121,Hydra:6.1.9,FMLib:17.12.100.49 definitions=2025-12-01_01,2025-11-27_02,2025-10-01_01 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 spamscore=0 bulkscore=0 adultscore=0 mlxscore=0 suspectscore=0 phishscore=0 mlxlogscore=999 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2510240000 definitions=main-2512030016 X-Authority-Analysis: v=2.4 cv=Rfqdyltv c=1 sm=1 tr=0 ts=692f9ded b=1 cx=c_pps a=WeWmnZmh0fydH62SvGsd2A==:117 a=WeWmnZmh0fydH62SvGsd2A==:17 a=6eWqkTHjU83fiwn7nKZWdM+Sl24=:19 a=z/mQ4Ysz8XfWz/Q5cLBRGdckG28=:19 a=lCpzRmAYbLLaTzLvsPZ7Mbvzbb8=:19 a=xqWC_Br6kY4A:10 a=kj9zAlcOel0A:10 a=wP3pNCr1ah4A:10 a=GoEa3M9JfhUA:10 a=VkNPw1HP01LnGYTKEx00:22 a=VwQbUJbxAAAA:8 a=Ikd4Dj_1AAAA:8 a=hD80L64hAAAA:8 a=yPCof4ZbAAAA:8 a=mjkPjPdUx_zNjNJ-uPoA:9 a=CjuIK1q_8ugA:10 X-Proofpoint-GUID: _fK-SjkYkPbIjwERVZsxMzMycL-1t2Ab X-Proofpoint-ORIG-GUID: _fK-SjkYkPbIjwERVZsxMzMycL-1t2Ab X-Proofpoint-Spam-Details-Enc: AW1haW4tMjUxMjAzMDAxNiBTYWx0ZWRfXyYpze4B4OZg6 vC8c6IBxuI64tMiETbrAlWfZHSQWOMml4tAAl+dWwij40OjXXFY4UfGf7t4k5/TsSzgdinWxVF9 K2eLjA0uAZevxzGGTSGo4eL6WxXLJAEOj/Fe9iW+wUrTo9DUMZp2ti0vdsxU94kYiZM+6Y3nGA8 MC8IPom+FIur3nLxm729t5ISjyo3Syi7oZJoUr0MCOOhCPPDw1JEodjwD0YjnjAwOF6LiANb1D1 EZmsFGgn8QSFXf1RJNQ7ue3qEsvaR8i/yJ6E4DMIMEudgcC2yUSFMT4wtkN8m0gFLp1MqadJJ1m m5ydD9l/lWWjEcqMPnCjCatFYcdQ6WgbtmBBiVSkv8YuVE8pt1tDcl7FKPEZFnghn9B+1hcNpfx hye0CPCEE5HciS1OyBGPa45PYMVZYQ== X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 0B8284000B X-Stat-Signature: woqssnwu1nhjwe63sm5rir3emprketes X-Rspam-User: X-HE-Tag: 1764728311-12379 X-HE-Meta: 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 JWNjbaap xUaeCmm9AeMWeucDbIQxo6vGawSkq4PKtupqy0cp6LzwU/Vf9LC9HvXPjHUG26oZpOU1Ez7p7FcAHoZvTjS0Tgo9/RsU/IY7gc2vSzsRfJe2Q7JiPcy5lGe6sXSvVDvAfKwrhOBXWQlCoiGdMdwI0byf1rrzaLBal7wyiLIwXSraXp7lE1iDjB21U9RBOSb4ssmDVSboFNxVunGDgFZxjP1BpmMlAxkSXImoTyLStMfSg3KVrM82J67eelF4vhNjEmW8WnuNFyICHw+FI4z/AtXI5LmxDwsjCOzjuyoCwfCSSTwv0GnTYnvkDMOYPCp0sBpk00uFazj2raY3SW/1AZM3yrc4qfpRlkhEbL8IiMHySDE9P29efmyg+V+NtyysbrLkg4xoSlEiyWgN9CCouI0bG9RdtBQb4+ECsMUbxKUSCYVXRKorb16Fd8tJbFwuEFiXUpTbrysH2uc4uv4tx9xNmBZVffyroS4ANRM5RSrA04eKuap58OO0G37EpjCyGINVGblbiDHJI/7MD3Aw61zJ4kPRMhgPnWFAchwwJwtX26yhqKxye4boPggEkEVPVgk+A7tPHwEiFSj7ysGyJY0QBhxKkP7HZ2nwL2N2ixWl6GF64OXuiVSPMc6EHMsfi/4tWHLZBfgfXcUT0vSJi+vtJefbv0YHIaObfQB4i/w5gcHP0XRfexBksThhO+vroC3kF1KsE1enCclA2UIncRQ4u1rKi53FVdnEoOhLbEYqlgY+YfNT2tzocJ08G6fY7KIT23IuEWZDB8110i6TOWjJINUgD1BbPlzjsWTONfHDHhjk= 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 Tue, Dec 02, 2025 at 07:16:26PM +0900, Harry Yoo wrote: > Currently, kvfree_rcu_barrier() flushes RCU sheaves across all slab > caches when a cache is destroyed. This is unnecessary; only the RCU > sheaves belonging to the cache being destroyed need to be flushed. > > As suggested by Vlastimil Babka, introduce a weaker form of > kvfree_rcu_barrier() that operates on a specific slab cache. > > Factor out flush_rcu_sheaves_on_cache() from flush_all_rcu_sheaves() and > call it from flush_all_rcu_sheaves() and kvfree_rcu_barrier_on_cache(). > > Call kvfree_rcu_barrier_on_cache() instead of kvfree_rcu_barrier() on > cache destruction. > > The performance benefit is evaluated on a 12 core 24 threads AMD Ryzen > 5900X machine (1 socket), by loading slub_kunit module. > > Before: > Total calls: 19 > Average latency (us): 18127 > Total time (us): 344414 > > After: > Total calls: 19 > Average latency (us): 10066 > Total time (us): 191264 > > Two performance regression have been reported: > - stress module loader test's runtime increases by 50-60% (Daniel) So I took a look at why this regression is fixed. I didn't expect this is going to be fixed because Daniel said CONFIG_CODE_TAGGING is enabled, and there is still a heavy kvfree_rcu_barrier() call during module unloading. As Vlastimil pointed out off-list, there should be kmem_cache_destroy() calls somewhere. So I ran kmod.sh and traced kmem_cache_destroy() calls: > === kmem_cache_destroy Latency Statistics === > Total calls: 6346 > Average latency (us): 5156 > Total time (us): 32725981 Oh, it's called 6346 times during the test? That's impressive. It also spent 32.725 seconds just for kmem_cache_destroy(), out of total runtime of 96 seconds. > === Top 2 stack traces involving kmem_cache_destroy === > > @stacks[ > kmem_cache_destroy+1 > cleanup_module+118 > __do_sys_delete_module.isra.0+451 > __x64_sys_delete_module+18 > x64_sys_call+7366 > do_syscall_64+128 > entry_SYSCALL_64_after_hwframe+118 > ]: 1840 It seems tools/testing/selftests/kmod/kmod.sh is using xfs module for testing and it creates & destroys many slab caches. (see exit_xfs_fs() -> xfs_destroy_caches()). Mystery solved, I guess :D > @stacks[ > kmem_cache_destroy+1 > rcbagbt_init_cur_cache+4219734 > __do_sys_delete_module.isra.0+451 > __x64_sys_delete_module+18 > x64_sys_call+7366 > do_syscall_64+128 > entry_SYSCALL_64_after_hwframe+118 > ]: 1955 I don't get this one though. Why is the rcbagbt init function (also from xfs) called during module unloading? > - internal graphics test's runtime on Tegra23 increases by 35% (Jon) > > They are fixed by this change. > > Suggested-by: Vlastimil Babka > Fixes: ec66e0d59952 ("slab: add sheaf support for batching kfree_rcu() operations") > Cc: > Link: https://lore.kernel.org/linux-mm/1bda09da-93be-4737-aef0-d47f8c5c9301@suse.cz > Reported-and-tested-by: Daniel Gomez > Closes: https://lore.kernel.org/linux-mm/0406562e-2066-4cf8-9902-b2b0616dd742@kernel.org > Reported-and-tested-by: Jon Hunter > Closes: https://lore.kernel.org/linux-mm/e988eff6-1287-425e-a06c-805af5bbf262@nvidia.com > Signed-off-by: Harry Yoo > --- -- Cheers, Harry / Hyeonggon