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 132D7CA0EED for ; Fri, 29 Aug 2025 02:06:52 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 394128E0009; Thu, 28 Aug 2025 22:06:51 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 344D88E0001; Thu, 28 Aug 2025 22:06:51 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 1E5838E0009; Thu, 28 Aug 2025 22:06:51 -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 0702F8E0001 for ; Thu, 28 Aug 2025 22:06:51 -0400 (EDT) Received: from smtpin25.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 8D8691191A2 for ; Fri, 29 Aug 2025 02:06:50 +0000 (UTC) X-FDA: 83828156580.25.185E222 Received: from mx0a-00069f02.pphosted.com (mx0a-00069f02.pphosted.com [205.220.165.32]) by imf28.hostedemail.com (Postfix) with ESMTP id 20593C000D for ; Fri, 29 Aug 2025 02:06:46 +0000 (UTC) Authentication-Results: imf28.hostedemail.com; dkim=pass header.d=oracle.com header.s=corp-2025-04-25 header.b=KVZffB7L; dkim=pass header.d=oracle.onmicrosoft.com header.s=selector2-oracle-onmicrosoft-com header.b=VHbO7AfX; spf=pass (imf28.hostedemail.com: domain of harry.yoo@oracle.com designates 205.220.165.32 as permitted sender) smtp.mailfrom=harry.yoo@oracle.com; dmarc=pass (policy=reject) header.from=oracle.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=1756433207; 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=Xx6QB1bvfPch70kzCWvCjct0FRmDIksZuJnqZVyzvUU=; b=g3TD1b/pVBluFmrdQgeOQ/4JkyMi2+QfCUO1GrhId/x/RYNbyOL6j6brEyTnN+DkoF+/9w Ydw45Wn5mgR350GHHlbQ5N6awFdFdgBJkkEHpSXkoYmbVHv+qE9w8aNvdO38dMFNw8lr6q 0AbfyaoemCc61Wyw+h4ars8EPLNWSs0= ARC-Authentication-Results: i=2; imf28.hostedemail.com; dkim=pass header.d=oracle.com header.s=corp-2025-04-25 header.b=KVZffB7L; dkim=pass header.d=oracle.onmicrosoft.com header.s=selector2-oracle-onmicrosoft-com header.b=VHbO7AfX; spf=pass (imf28.hostedemail.com: domain of harry.yoo@oracle.com designates 205.220.165.32 as permitted sender) smtp.mailfrom=harry.yoo@oracle.com; dmarc=pass (policy=reject) header.from=oracle.com; arc=pass ("microsoft.com:s=arcselector10001:i=1") ARC-Seal: i=2; s=arc-20220608; d=hostedemail.com; t=1756433207; a=rsa-sha256; cv=pass; b=wtWybT+z6nIZDyScok6rSj5H3aF0pCnEuBOTkKCjTbTkdbmggxJqhx5vfqee3j7GkwuecV qtxVnST8+Ey2Q9dWOkdPVjXiukFeP6NFrd6+NWSmdZxzx1/mqdHiQqxBY/NyVk/Sl7wcXR 8oCQaJg8Pd65tTEjjPhaMiNwygegoA0= Received: from pps.filterd (m0333521.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 57T1frxM008401; Fri, 29 Aug 2025 02:06:36 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=Xx6QB1bvfPch70kzCW vCjct0FRmDIksZuJnqZVyzvUU=; b=KVZffB7L6HWtzndVEavaONKoLRQu4Aymea ygzSovuJ50CpFNSW5Oxs8QoSA9+AbBWzyS6bwXfrGkIMUcFbdwEDg7WXyMaV3NUm oUAN73mTNFgk/YRExxjeerJgdPJZgq2Pd3MtLo+GHErEXl4Pn5HvmrPnG+BarE0e NI5GR8VwxevJ4JGSbPe+IBIBxSvDjb0obdTcRDwxBo7UBsTonzgvWCF8EL2GjDLb YwSw4XcIPtCM/lZrC8ALLn+sO2iffFcG2JwDxN7lGvlq2rEnM0eC5vTIswYG641V ivrjQMhRby9k+d7soqDawc+MPBxxoU7147TarZokxc1eNCp+JzzA== Received: from iadpaimrmta01.imrmtpd1.prodappiadaev1.oraclevcn.com (iadpaimrmta01.appoci.oracle.com [130.35.100.223]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 48q4jaspbe-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 29 Aug 2025 02:06:35 +0000 (GMT) Received: from pps.filterd (iadpaimrmta01.imrmtpd1.prodappiadaev1.oraclevcn.com [127.0.0.1]) by iadpaimrmta01.imrmtpd1.prodappiadaev1.oraclevcn.com (8.18.1.2/8.18.1.2) with ESMTP id 57SNo7pd005309; Fri, 29 Aug 2025 02:06:34 GMT Received: from nam02-bn1-obe.outbound.protection.outlook.com (mail-bn1nam02on2081.outbound.protection.outlook.com [40.107.212.81]) by iadpaimrmta01.imrmtpd1.prodappiadaev1.oraclevcn.com (PPS) with ESMTPS id 48qj8cus1a-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 29 Aug 2025 02:06:34 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=nkcnfN6s4o9nYckXyBrLQqLz6SrOj9GLwAZpLQzbljURMW4kR7gRO/6liKGkfKhYAAlKYb39FVF3TPlUWkL5rWh0yHP09ccSZNJ5At2A8jwhQdn3QmDFRmiL/UxPW8JVbDGkHYOE0FMqYXt4cdHvG6ozZ5o7VU7z6plCItLtP5TCuTXci3cK52ztoxUb+1xxNFehieEvIITL4amFtCTpNLONitCmjDGTcVeXanCB2pTByEBJrGi1uZ/9xw8DmmEG7C+c+hlP/qb2L9oWQTU2Va18Zf46RR0SuNjBmD+4fcn4ttsFMRvmxzHe35jgrxh2I5URg90bXZLe7xRrWIr6Hw== 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=Xx6QB1bvfPch70kzCWvCjct0FRmDIksZuJnqZVyzvUU=; b=oLrzjsV3mA0MFIiKm2U2FPEyskyQCqfOhINSQrZe8frdMnnJGuGLz/EPVxx1Qpy2rz/Lh3a8CMrh4IOMAmm6VqKqB2S5ax9H5JbQH4FOeg7K66joSsBXDRMLoQ+Ys3rTH073upLaorTyIsyWDPR4kP24I4lH9TrUeVG336yEhGPBsWBEfncIHlzriaEFNPJBdrBkluIm7Hcu6QJ1JIpssQB1Vyas5kBrsX+KobnEmw+0Agg8GFZHCGs8Mda7pQgX4XcE5VtSLGLS/Oh/LOuZQ5U5yqrE4ISazxQHFWUgnRyPUuOeSEXoAAxqcwhQl1Fl9KPKYIQYu22YkKZtnJu1CA== 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=Xx6QB1bvfPch70kzCWvCjct0FRmDIksZuJnqZVyzvUU=; b=VHbO7AfXtGlSONzKG71r+PKkVCmbX++IENVRdb1KRnThmnv4TvO5ZzUpl6hL0WK467Xkzq7PfdWLuNKXqd7UAK4h9JC0x0GY1UhnptO77cjtMiGebHDDRD5yns28nViwbSAVg/1yA6X3JR/jzhizRu8g2JSeYVPIVeikWNegBjo= Received: from CH3PR10MB7329.namprd10.prod.outlook.com (2603:10b6:610:12c::16) by CH3PR10MB6713.namprd10.prod.outlook.com (2603:10b6:610:143::20) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9052.16; Fri, 29 Aug 2025 02:06:28 +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 15.20.9073.010; Fri, 29 Aug 2025 02:06:27 +0000 Date: Fri, 29 Aug 2025 11:06:17 +0900 From: Harry Yoo To: Kuan-Wei Chiu Cc: Vlastimil Babka , akpm@linux-foundation.org, cl@gentwo.org, rientjes@google.com, roman.gushchin@linux.dev, glittao@gmail.com, jserv@ccns.ncku.edu.tw, linux-mm@kvack.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org, Joshua Hahn , chuang@cs.nycu.edu.tw, cfmc.cs13@nycu.edu.tw, jhcheng.cs13@nycu.edu.tw, c.yuanhaur@wustl.edu Subject: Re: [PATCH 1/2] mm/slub: Fix cmp_loc_by_count() to return 0 when counts are equal Message-ID: References: <20250825013419.240278-1-visitorckw@gmail.com> <20250825013419.240278-2-visitorckw@gmail.com> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-ClientProxiedBy: SEWP216CA0153.KORP216.PROD.OUTLOOK.COM (2603:1096:101:2be::12) To CH3PR10MB7329.namprd10.prod.outlook.com (2603:10b6:610:12c::16) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: CH3PR10MB7329:EE_|CH3PR10MB6713:EE_ X-MS-Office365-Filtering-Correlation-Id: 7b4c214f-fb3d-4a59-fb56-08dde6a0a9ce X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|7416014|366016|1800799024; X-Microsoft-Antispam-Message-Info: =?us-ascii?Q?/ME4a5PEwsWkw1MeNQrKS64cl2FV/L3EE5VJFMvHPJO5toKyEPZg5klImve1?= =?us-ascii?Q?+z5cAretvUATt7Nmg+o3lfnGQ3l3dVXOV8RaU1f6QX7lAmKRE4v/dH8Y2yGd?= =?us-ascii?Q?STk7I2WBhHB8FekdvPzHprI51wBOIYkqjtNwgQFoFS/PYwV8EZI7rWg+tO56?= =?us-ascii?Q?6RalPJEHIJkSasrA4bj+zCxr6FjY/8bpa4E0n8/9Zg8TMioKuHJ+q5aKSlQq?= =?us-ascii?Q?WWjenOHnmH8WVIVmY0Iz0ALwZH5WbTtlTZah4DRowmaqpMf4AGIvZ78/qn7K?= =?us-ascii?Q?yMJ0UHnazMhxZ0bf1QtGH7rP7rEifhKW/DZnZF+FdQi8+Dcz78g5kU2xy+ct?= =?us-ascii?Q?5LLcoiROQ/OfOdreYAiGNuQxTFz15Nzp92/G5Yk5U7KguYSccLg5owgXXaq6?= =?us-ascii?Q?rbnfatWyj1O8KBBQO11hp+HgS2wPBkMNDgZsBOiHjXTqd5Ckp8ZI7NFmT3Ol?= =?us-ascii?Q?hrvfR4vmf7siQ3PxlwKYotiu5hAHl8Hh+IWmqp2DAolsu7dGxGy/yKi/6B8S?= =?us-ascii?Q?BEyinOTfY3LmkGO9umkpwt0TQUhJFgg2RvUZhpE4rbepkugWUUtg1C5RWGdX?= =?us-ascii?Q?gOvTbDnyiaUpLnR13saoJc7l1jzWEZlvjDMXa7dO7HGhVEfLUWHwmK66FJcF?= =?us-ascii?Q?S1Fhv63Y9B+qOPV7/GVZjXjPcFiioHlz2twLzkSFJw/jZW0nwgr9PiS9cjI6?= =?us-ascii?Q?Kb5KYGDRRvABq9HNb9ljAymXQc9TZPc5sNHcMu5KA8s83kdh8iYia7eOYmK+?= =?us-ascii?Q?PhjdPSKduVSAHt7q0F9wcQY2HYLRAYAPLN7jGTfY4/M33IMOf2IQZyyq8ccp?= =?us-ascii?Q?w9PNO0+RH9cRXjhBzrNVhVkFXrtRwUqCbugK+xJvsAGIZ847HaGxgIi3fHth?= =?us-ascii?Q?0v6G8jrEsY1wSzqfayw8Qq1ecTenf0a/scAkoCmi+Dks/X8TMup+mHLeC/7K?= =?us-ascii?Q?O9RvyAtvWkl3aVfiUK17yktVuVeq259zfA9L2N9MkSV3A+zHeS4VTEarBVIZ?= =?us-ascii?Q?gZXn1KH++kcxA7HJ90Q3KgNcDGymmloiah4dgY+lN8St5pSTqEuLS4yO3bjG?= =?us-ascii?Q?Th/hP+MMUfM0tXJUqoTu3wSZNnpzqzRBzhpBCd+HPIu2qp1C7YIRw1Pzh3Jp?= =?us-ascii?Q?NMXDY1oyaDijrwV6PMf9GN6zpHxg90u52pmp+E5EsOkvQvmbXIpxlhJIROdp?= =?us-ascii?Q?6gUwG31XnHkbMk1072t1wg2IOzQZeI8TcSWWfAIt+Hdj6rD+aBSirajUvmt4?= =?us-ascii?Q?e+Cf8OwqgEuR6BsB8uNME51kJ7S+E4uMs7K8eDWrvYrkXhHAFMbnZ1VTSIf6?= =?us-ascii?Q?ZyIRJce3Y5hKScARqKpaWChvDG5VNWlQD4FU6RWAuBcvKKYm6ZsNgGtCDSVa?= =?us-ascii?Q?fdTT7sRs4rd0jVBfcz9+AJ9SBp4EhnIHYNDEhL+/3FZZD6rVIcVK5//Hw4Ku?= =?us-ascii?Q?a1tKGm3J1D0=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)(376014)(7416014)(366016)(1800799024);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?6Chgv91HqpLB3AsWxFPKS6s+2etpitj2Wrf200CaatuWN/e7kVglS+HRJG1f?= =?us-ascii?Q?2/W2cwXlAYO9OhQngIulg+PsYU2yfHvcjLmSazAsiB+uJxcITF8PYAnUnbEw?= =?us-ascii?Q?mu6is0N8FZQprRIUfW9CHtPx1A44HaGG9/4CBveSIDgXM8JkdRB0UPgQiPZL?= =?us-ascii?Q?R/gOPijhZzkZnEvTGBtsTzwCPr8Zqgc4UnST+mvWBu8VEbU5sKTTNvkRoUq+?= =?us-ascii?Q?N3QGKOQpG0dKRhh7TNMpobT+ezizJOS6qF+cLevsE5j/5LKTVd6yb5IlPJSs?= =?us-ascii?Q?4RfP3anuC5HilqZKLibCQlNEnqHhf1VlMHikDLP6AU8b8+x59QY74EnpnSqq?= =?us-ascii?Q?C5jmbSA2UqBi3R4ngQShCMJZYclZxnsh6dfUnaBsQH7fsNW73tbPx1xKPw+Y?= =?us-ascii?Q?f6jBNw1Lzd20eTvx9wOeTAi6s4HepEhc1l3ZekNM1CfZS8jFjMHpwzJokH9H?= =?us-ascii?Q?BC2Vab2GbOtLq6jL7P2ROq5Hsw8gRESPuvGJdKY1zBcT8gf1ow7gcGkJ308Y?= =?us-ascii?Q?nt24muAJmqQzL/Bj/s1Bf2Q3i0yZLQbE9dNUzFPXOGuOI2dFLfe6BqXB6lE4?= =?us-ascii?Q?EQZW2j+YlRqaAJGTV2t0GHUbCq33153rIcQUuvitx+M/S2vrq2Q+Ij6gH/PI?= =?us-ascii?Q?BPw5YCNtTkmHkD2uV5vI1PnIXXZJHvlm2oKEu56DU8ynnXAuGSRuzqUoHbfW?= =?us-ascii?Q?ujJ1c9vpU59mtk/t5kGAXiYCL17bRhNJazzsVS/IpcJuP++kDtWiBEK1Xb5h?= =?us-ascii?Q?PgZ8ueV0B6I1XslWOt+WNMQWar+sECvrTsMGWch3Npq81V4Axsq6C+9Luwmy?= =?us-ascii?Q?VVMpHVYLW1kZSr+KY9brW4pj30ddGFXiUpTdycfJ9IT9dWnitGT9QiIdgb2s?= =?us-ascii?Q?1oJr9dWyv1iQ59zChF5pLhLrWd4rHl0HuWBm4OYSYdQoXDuce2+dx9SiT4+Z?= =?us-ascii?Q?bd2BVMLm/EjvGswBMSeQfzS0XBPEdBrZftBl/FBLtXftqxnVgT5mQRmIzNwc?= =?us-ascii?Q?Ikx24dRTVzihbvvyx3fZk2jhHsOD/rqiiHllvnBing1U0AmopFiCX1eVxyuw?= =?us-ascii?Q?LY4QOsWkCuXModWz+3RuIkn0yXXal0YjHc8HgbgKrrbDjtSiH9Y++XsdBCVA?= =?us-ascii?Q?KuPOHc9MCAGuuRZgzS6aa8XdtbjjCH+iT3UwvygIdk/v4Ls/LKR2GKV4jqck?= =?us-ascii?Q?j6SrNMzgSU4bKAMA5ofApQwvnbywGQhpRXrsuoACovAvmjseqQ7RKane173e?= =?us-ascii?Q?1SxqUMQb422aT3yCxShxf1KXUrvv69PMP/VOmadEUpHjuoebHFjuypO0O+mu?= =?us-ascii?Q?9yqKyBwULOKGZvs1UBc7FqrVG04Na13lGRgA8h6tH0zdkambJSWc8+YbPyBJ?= =?us-ascii?Q?ls5U2QnBijRJQiqSrE90kMswrx4wKDRg+bwJmChLe2FD58PDA7jZCFteSM0o?= =?us-ascii?Q?ZQemgHTsLNTTKxcXPs/1yndjTO5eUgWKezi5Y0KriV5GcZIYwbq+uZuGi7k7?= =?us-ascii?Q?sXX204Ro2z7XXXekWfQZ36diK9bxAGyh+yeYt+A6A4VX4gzZRYnUW1UWhcnd?= =?us-ascii?Q?8fqvc2sp1hy7t0o0uKde1FFtnG5qZM7fqkWTl5N7?= 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: 7b4c214f-fb3d-4a59-fb56-08dde6a0a9ce X-MS-Exchange-CrossTenant-AuthSource: CH3PR10MB7329.namprd10.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 29 Aug 2025 02:06:27.6936 (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: Xzqyc/Q4oQ03MexMN09SAr24tLLaa4oCKIHLZfRJi+v+yg+a+ow+swR0i7jq+exdIkb3y/pflR3dxyhlmi5Z/Q== X-MS-Exchange-Transport-CrossTenantHeadersStamped: CH3PR10MB6713 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1099,Hydra:6.1.9,FMLib:17.12.80.40 definitions=2025-08-28_04,2025-08-28_01,2025-03-28_01 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 adultscore=0 suspectscore=0 spamscore=0 phishscore=0 bulkscore=0 mlxscore=0 mlxlogscore=999 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2508110000 definitions=main-2508290016 X-Proofpoint-Spam-Details-Enc: AW1haW4tMjUwODIzMDAxOCBTYWx0ZWRfX1iqUALlyR4yE /ZV3KzTFeNxiqY1kVOKxVmTr303uUQ/bIK8Epvu2wEjjCiWZbq1iisCvM9CJyYcxAvv4bHnKUt3 tFAOOLS9YqeFKuNpuW44diSOSgNWJLOqCEaaqP01X2AK8fRfgKoAepzeN2eVk+DCjkSARmy4E5g WefMv8AkKOWVSOYBaWAgQ+o0dbqREVYOUFjiA3xbsSTIcYqU1RaTQdprrxe+j155XvvmIB7vA8Z MX0CrbYLp2PbYzUvwpebwn0Ldf294++bqy3lHIVpuc48ezVPMeCQRWOAB4IMpezTsQysoXCaQs2 skiklytVHYoP9QqjcOhTXRkPGGj6hRXf47tEtDCE3MW29wwRoYkE0sjKe+9MMmU1hTwNkBHMgri Ifq+IGxgIuhNi7yRtaVZrJjIlJqU9Q== X-Proofpoint-GUID: 2cLPU0pwPXTYLK2pUbw8z-YHeUVtIfDa X-Authority-Analysis: v=2.4 cv=IZWHWXqa c=1 sm=1 tr=0 ts=68b10b2b b=1 cx=c_pps a=zPCbziy225d3KhSqZt3L1A==:117 a=zPCbziy225d3KhSqZt3L1A==: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=2OwXVqhp2XgA:10 a=GoEa3M9JfhUA:10 a=VwQbUJbxAAAA:8 a=pGLkceISAAAA:8 a=CuuHCt6lwlVgYl5tIdUA:9 a=CjuIK1q_8ugA:10 cc=ntf awl=host:12068 X-Proofpoint-ORIG-GUID: 2cLPU0pwPXTYLK2pUbw8z-YHeUVtIfDa X-Rspamd-Queue-Id: 20593C000D X-Rspamd-Server: rspam04 X-Rspam-User: X-Stat-Signature: ufzc84u461njbsztzyy5yr4etduoynum X-HE-Tag: 1756433206-279429 X-HE-Meta: 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 B3uh8KwP 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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 Fri, Aug 29, 2025 at 01:13:58AM +0800, Kuan-Wei Chiu wrote: > On Tue, Aug 26, 2025 at 04:53:34PM +0900, Harry Yoo wrote: > > On Tue, Aug 26, 2025 at 01:54:49AM +0800, Kuan-Wei Chiu wrote: > > > Hi Vlastimil, > > > > > > On Mon, Aug 25, 2025 at 07:28:17PM +0200, Vlastimil Babka wrote: > > > > On 8/25/25 03:34, Kuan-Wei Chiu wrote: > > > > > The comparison function cmp_loc_by_count() used for sorting stack trace > > > > > locations in debugfs currently returns -1 if a->count > b->count and 1 > > > > > otherwise. This breaks the antisymmetry property required by sort(), > > > > > because when two counts are equal, both cmp(a, b) and cmp(b, a) return > > > > > 1. > > > > > > > > Good catch. > > > > > > > > > This can lead to undefined or incorrect ordering results. Fix it by > > > > > > > > Wonder if it can really affect anything in practice other than swapping > > > > needlessly some records with an equal count? > > > > > > > It could result in some elements being incorrectly ordered, similar to > > > what happened before in ACPI causing issues with s2idle [1][2]. But in > > > this case, the worst impact is just the display order not matching the > > > count, so it's not too critical. > > > > Could you give an example where the previous cmp_loc_by_count() code > > produces an incorrectly sorted array? > > > Sorry for the late reply. No problem ;) > I tried generating random arrays to find a concrete example where the > old cmp_loc_by_count() causes a wrong ordering, but I couldn't > reproduce one. So I would like to withdraw my earlier claim that it > definitely leads to incorrect results, since I cannot demonstrate a > failing case. Yeah I couldn't either. Maybe mathematical proof would work, but I didn't try. > That said, I still believe the patch should be merged, because sort() > only guarantees correct behavior if the comparison function satisfies > antisymmetry and transitivity. When those are violated, correctness > depends on implementation details, and future changes (e.g., switching > to a different sorting algorithm) could potentially break the ordering. Agreed. No doubt the series is worth merging, just wanted to clarify that bit. Thanks! -- Cheers, Harry / Hyeonggon > Regards, > Kuan-Wei > > > > [1]: https://lore.kernel.org/lkml/70674dc7-5586-4183-8953-8095567e73df@gmail.com > > > [2]: https://lore.kernel.org/lkml/20240701205639.117194-1-visitorckw@gmail.com > > > > > > > > explicitly returning 0 when the counts are equal, ensuring that the > > > > > comparison function follows the expected mathematical properties. > > > > > > > > Agreed with the cmp_int() suggestion for a v2. > > > > > > > I'll make that change in v2.