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 1F41ECFC503 for ; Fri, 21 Nov 2025 20:24:41 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 2098C6B0062; Fri, 21 Nov 2025 15:24:32 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 1962E6B008C; Fri, 21 Nov 2025 15:24:31 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C6C606B0093; Fri, 21 Nov 2025 15:24:31 -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 468EF6B008A for ; Fri, 21 Nov 2025 15:24:31 -0500 (EST) Received: from smtpin10.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 039BA1606BE for ; Fri, 21 Nov 2025 20:24:30 +0000 (UTC) X-FDA: 84135741942.10.0E835AA Received: from mx0a-00069f02.pphosted.com (mx0a-00069f02.pphosted.com [205.220.165.32]) by imf01.hostedemail.com (Postfix) with ESMTP id 6372440011 for ; Fri, 21 Nov 2025 20:24:27 +0000 (UTC) Authentication-Results: imf01.hostedemail.com; dkim=pass header.d=oracle.com header.s=corp-2025-04-25 header.b=evlpZ3+4; dkim=pass header.d=oracle.onmicrosoft.com header.s=selector2-oracle-onmicrosoft-com header.b=zs9IpSLz; arc=pass ("microsoft.com:s=arcselector10001:i=1"); spf=pass (imf01.hostedemail.com: domain of ankur.a.arora@oracle.com designates 205.220.165.32 as permitted sender) smtp.mailfrom=ankur.a.arora@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=1763756667; 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:in-reply-to:references:references:dkim-signature; bh=A7YJVfgIlnS5kANFa3xwseJm17GMLncyCGn4THht150=; b=xVcJuyEFfVMr76k/rOql/HKKA8iffaBYF+5NLZDheR3oucvxW78EyxlGqOACCZUhX4E8eE So9aa6lNK3qhK96YqdAWA0b38AYyxZUaDYCrIqL5w9ggiL8VC7anZqGFTxQzTTmIHjQ3Yw LhXUZnQxbRf8KTpTD0yO9UjlBvTTL7c= ARC-Seal: i=2; s=arc-20220608; d=hostedemail.com; t=1763756667; a=rsa-sha256; cv=pass; b=Ux1k5wNIiPdQng/A/vKJhe/pjYXKNdiTe788vfBPXLFz6Gz/P6MTUIi7iP0WEmkeW4fPac 9OJ+Pq+loc1RtDwie1wBw1tHmDUsFeLK/lomwZ6849BMCJqac/dVmdQuIfWUNv8KsIESu0 kOyk3bRx7vxU0ymm2qVMly8rVkXgFog= ARC-Authentication-Results: i=2; imf01.hostedemail.com; dkim=pass header.d=oracle.com header.s=corp-2025-04-25 header.b=evlpZ3+4; dkim=pass header.d=oracle.onmicrosoft.com header.s=selector2-oracle-onmicrosoft-com header.b=zs9IpSLz; arc=pass ("microsoft.com:s=arcselector10001:i=1"); spf=pass (imf01.hostedemail.com: domain of ankur.a.arora@oracle.com designates 205.220.165.32 as permitted sender) smtp.mailfrom=ankur.a.arora@oracle.com; dmarc=pass (policy=reject) header.from=oracle.com Received: from pps.filterd (m0246629.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 5ALEgsWi014546; Fri, 21 Nov 2025 20:24:10 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=cc :content-transfer-encoding:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to; s= corp-2025-04-25; bh=A7YJVfgIlnS5kANFa3xwseJm17GMLncyCGn4THht150=; b= evlpZ3+42tJehOaieT+54xCQL64Ct793aPC/uw/ktMJsaIdzUAjJh4OQLnDE3z4l p2Mu7I4E5zghZivEsiPdgyMnBo4qpzKYdgqHuuPzurbaKC2mCSWIOQRAl08tqwDn /x3vjBzAx0mqwJYI13Z6uL9aKM6cu3Idnb9AVcEc/CBtUh8nNgSrxhhXiorTPRMn lwFUQIT/LA7qiLw8sxxHQpDgWzQr7gwnY8WRKS1ERD/KuvN3Fgq9ZVNwTyokPXnl XVJdBfO1luUio3NVe2UzI6bqOEFrU3sREWV/Lbr0JjtZmPFvEj93oTxfGZjoxoIB CXizs+s9wxNTNZZPxO/+nA== Received: from phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com (phxpaimrmta01.appoci.oracle.com [138.1.114.2]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 4aejbuv6ge-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 21 Nov 2025 20:24:10 +0000 (GMT) Received: from pps.filterd (phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com [127.0.0.1]) by phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com (8.18.1.2/8.18.1.2) with ESMTP id 5ALJY0Mp004449; Fri, 21 Nov 2025 20:24:09 GMT Received: from dm1pr04cu001.outbound.protection.outlook.com (mail-centralusazon11010023.outbound.protection.outlook.com [52.101.61.23]) by phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com (PPS) with ESMTPS id 4aefydufpv-2 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 21 Nov 2025 20:24:09 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=mBTokBD7BlEJ0hdTw0pa2RgY21etB7jY+fIZoxJROGVRhDzKA7FXbDw94Z+zDUX09z7zCL5ygevg1lAROXkFvorCLeFdeJQExdrNaLXRDwPxI214+tSZ/aigzP0HBIqVL09ukqfqlOAkvIwyzZgOkEuf68kqe5S43PT8+OSMHx34ebVGZHdVyY2V2ieVEfQQfMCA5WV+cDhBBw4xzDUBQCWHB/LYn5dpC1/q8pp47+2EVa7Zn+WIlnY1w66pJutS2kPuCgZ7zq5qnPVv9a8+UGhyIjZPbHMLNYTUwIwiRje64rObQeX5xwV4uCCapC7mjs+iw3LlMwItWDuMTB7wIw== 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=A7YJVfgIlnS5kANFa3xwseJm17GMLncyCGn4THht150=; b=aBORlGxpAfeiZlvxkjOnj08HW7S2QuukeZKrhzGuElZnvUZfj2QG7X4I2bN2EwL20cuQI9GcEGY6nhOc3aC07Xg/tJto3GKhrpHF3IRTF3+r2bhknxBT2AxiCXEn0HZOvIZisYjhwsoYtY6V+TITkHII6UAtl06VSh4upIzxVpsAQ02g5LEE36rvbZlOB1RNGvfDZqBkv5efbmerCDYjyNA4ezacedyFfWmMqDuod4vKaBqfl409xLolBCS8BWh0bkM5bvgdg6WC+xy0DgvyBN9zl2U+ZikGM/eI+Ex6coi7MQs3MbLKMaHzvS6re/DUwM7awgps0kowMkRu0lNDkg== 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=A7YJVfgIlnS5kANFa3xwseJm17GMLncyCGn4THht150=; b=zs9IpSLzGAjyNtGewIGKQAKU+y9MP1f2O5sCXbM8d6QFALZo5n4QjlnthJhInfW3quJFVfSWveT/p9FWpTP9m+xJO5yjCShv67XUDUb623r0b+rcyuMYCeFYieVedOVfJssFakOw2k7B4enLQ/TnjAcotgzFNTRlK82Kdy1u0m8= Received: from CO6PR10MB5409.namprd10.prod.outlook.com (2603:10b6:5:357::14) by SA1PR10MB6470.namprd10.prod.outlook.com (2603:10b6:806:29f::6) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9343.10; Fri, 21 Nov 2025 20:24:04 +0000 Received: from CO6PR10MB5409.namprd10.prod.outlook.com ([fe80::3c92:21f3:96a:b574]) by CO6PR10MB5409.namprd10.prod.outlook.com ([fe80::3c92:21f3:96a:b574%4]) with mapi id 15.20.9320.021; Fri, 21 Nov 2025 20:24:03 +0000 From: Ankur Arora To: linux-kernel@vger.kernel.org, linux-mm@kvack.org, x86@kernel.org Cc: akpm@linux-foundation.org, david@kernel.org, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, mingo@redhat.com, mjguzik@gmail.com, luto@kernel.org, peterz@infradead.org, tglx@linutronix.de, willy@infradead.org, raghavendra.kt@amd.com, boris.ostrovsky@oracle.com, konrad.wilk@oracle.com, ankur.a.arora@oracle.com Subject: [PATCH v9 4/7] x86/mm: Simplify clear_page_* Date: Fri, 21 Nov 2025 12:23:49 -0800 Message-Id: <20251121202352.494700-5-ankur.a.arora@oracle.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20251121202352.494700-1-ankur.a.arora@oracle.com> References: <20251121202352.494700-1-ankur.a.arora@oracle.com> Content-Transfer-Encoding: 8bit Content-Type: text/plain X-ClientProxiedBy: MW4PR04CA0050.namprd04.prod.outlook.com (2603:10b6:303:6a::25) To CO6PR10MB5409.namprd10.prod.outlook.com (2603:10b6:5:357::14) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: CO6PR10MB5409:EE_|SA1PR10MB6470:EE_ X-MS-Office365-Filtering-Correlation-Id: 8e220f75-0ef7-486b-949d-08de293be95d X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|7416014|376014|366016|1800799024; X-Microsoft-Antispam-Message-Info: =?us-ascii?Q?qqNhLktrZGrUrRG8pnyU7ZDmC8C3xr7jK4hCjFPRim/k2Yod646Z1FinYz8T?= =?us-ascii?Q?LDbuDou9TF9LO55TVgBT5lgMt6EPdQzD/m11S7YDXzGWur9IIDPVtjqrHyKw?= =?us-ascii?Q?zixkMWKh8+rtFlJ48VG9RXO2LP5WKGyAorT5LC5/ws77HTrryLEDU59NQZGv?= =?us-ascii?Q?qWKCZ2BpBAVEYSg1uq8UHb8w/4KcxSA/lKq9HEwW2AH2PGDyxXkKZ3PgY7mM?= =?us-ascii?Q?Mt2BpPKTw8GlVxc8InaWNNIjqN068MI7RxFRHg/+NLIgAYoO4q6+6Arx8juF?= =?us-ascii?Q?/Ik+lOhH6dIg6kg/xaAD4sUYbwCf7HrU53Icd8SYvG2ShUQm3a+iclvXSToX?= =?us-ascii?Q?0DdCIvJtdY4KFx/YUh2N+IxwDcLPTm7N1dhElVYOhJq+e6cFWwW3QeEcq6hN?= =?us-ascii?Q?GNFYgWLkt8WDT9cJWH5dr4P/hYhG45jlEXgo2FGtY4UI+8qn7ADiS8MG++Gk?= =?us-ascii?Q?uUIqMVyjvGsPserbO4g/1ybcF953IwHFSg8DH+IKJWzMzO9RONUj9G0J8Z+5?= =?us-ascii?Q?iKyHWFhjn/h2GlyMv9m3vdFhLpMOkBYBBkYIYQfCuBWTI/9mucDZ8z2yX3aD?= =?us-ascii?Q?LQYlR5pBXgGgWpwN2IIwAQ72uOL/1tr9g9nJdBHYdaLYpRLQHm7hxANAR+pm?= =?us-ascii?Q?lGCgve7dizJRxCGimk80c+ziPVQGOtcCW3+3UgZ/ltacm5+Z4nxy7udp5iF9?= =?us-ascii?Q?o9B6Fy5P0efThWtzWDRNmUYqYjlfWVgGyAjq/Fh7xpQkkRqtfhej8w1nXj4u?= =?us-ascii?Q?6p1r23dMf0q+Rh0ny1YyKhYe6kJXoS5ikaDaGaKoOxAlNC/StfLh6Rd+//Mo?= =?us-ascii?Q?TtlteUruETZkUN7exhSonrsqCjuvyMAOei5OkpzKyLjbjUfqWEYgxbio7kCM?= =?us-ascii?Q?Wsc0nddcKqszRYkFYfBNyGrEd5y0i3lRPYpBmVWXMyTYVmdID+DpzDw7doCo?= =?us-ascii?Q?pSb+WuJ35ZJ5655vi7yWUx1pyQu5EPDNmqwpu413w423MlR8RugNH62Nebta?= =?us-ascii?Q?ZFhFjvw05snzxJz7ubk+h0b7NghagJqm2RDe+BQtBAg4y8S/NU0vxPIu+1q7?= =?us-ascii?Q?m+pfdiLkDEgo1Be4Ig80qAtfIeP5hvdkz3T8W/wr4uKIgBb9mcxbrGXW7PPE?= =?us-ascii?Q?xnROlmoMxRdwhci7ti3AfaZvww14cAQi0H7xqcDs7lZDvr36IQ11rXZR+VJR?= =?us-ascii?Q?+UZua27YrGe8tLWafEoGYyNfLnKUd9OzoaZtifwlb8WSwkbbtIVOGIdJVpt0?= =?us-ascii?Q?fR321rsEid1aRtAkqdZBZ0AmN+41iblXXXmHVJdUevG4zaVq9ppRJiH62uch?= =?us-ascii?Q?/7ZqdG3dvt811kCh7K72nYc3bmAGA6ey+79TxBibWI4GFjGvsMWru3F5i4RL?= =?us-ascii?Q?GdVhODhsOxwQ58dtno8JA/GI0JK7n1LfhyFnoDruQ2ngzxPbWjooi8pr1brK?= =?us-ascii?Q?FCm61itf55U0+xBcy2vFgDdvvYJ36U/O?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:CO6PR10MB5409.namprd10.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(7416014)(376014)(366016)(1800799024);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?BLeVihZ0S4ipV+j2kWgENgLDm1UtqELNZENfu5WZozxcI9HSkXdkxmjigQFd?= =?us-ascii?Q?4d7QkAXMMYCCqT6tnhmbxHMMwroAj1NZj5WGvWrDS532rvLkzahRhq+eWSob?= =?us-ascii?Q?KK2ttMg2ZVW+PcLwBD99tvUJz3mICEWGH0nbFtiqrvg6SBoycjvpQWeB6Qp/?= =?us-ascii?Q?AoFDh2zvY3RIb9jWbyzXLK2yvYpnwXk+qNgsLxelUWr5SwrcGY+Vros+lTNG?= =?us-ascii?Q?bD74wYecWPG9QjMSIlMFp7PrlJZBFFyodMOXe4FwtjBQ5+EeU6Ap/6S868u/?= =?us-ascii?Q?m+JoyZb8q/VASJkwTFCT4T4vead4mW9mpNSuEw7fcH5DNCwR1TN2epxudqnB?= =?us-ascii?Q?8ccUJXZZ63ii2hebD0N+r8apRjoc+N3YeAy+wK+9HLP5qHWFuYQJf9AS+ijc?= =?us-ascii?Q?phRB6asOuN7i2kw8W29gi+ksQVE7i1JB8glxARjFZueOz3mj1LjIlfgehzvq?= =?us-ascii?Q?6ca/RkqqykHqSPIc7Vae3adUQfaE8SFsDNdYre/uXZa2YNnvMjxbuH7txcV0?= =?us-ascii?Q?+nBnkY3HH5iewjRHsLDlhIIpoRzezlqwyuCEH5Goy0CpUDrnyP6LbDyr93F9?= =?us-ascii?Q?w7XcQu99ToOjkqvEVuXmzLc4Riau0o4oMUf9u9WZsz0Y0pWaWvqICzWPtbew?= =?us-ascii?Q?lBMUfaQE7fCMg8QgeU/Gx1JgUop2f2AB8hXTC3pNY2lEg4mcanq9MZZQ8YRu?= =?us-ascii?Q?RmdICCqf4X4mmhChyob3YsNQd5J8ErAI9ZolmxlTQiDagnfcU+ZWySWas2FG?= =?us-ascii?Q?F6lMvY16oQxh2pG618ezbNLahOHUpggwWEm1Leki+AIX+F4UPk/cMK86eXYG?= =?us-ascii?Q?W63lMiu7GA3B+9Q58SeuCVhqyf9MpIyQXhI5KM3xIGOOOqll9FmEtauSFGSo?= =?us-ascii?Q?4tDF13R/o24ZaVydEgxwVPWH9n+2W0Qnk4jYY6lmFJt/uaLLLqAdulXNyMuc?= =?us-ascii?Q?LkIVimLKe3f+Ur2El9I3ydfLZiBa5Tw360Yt8BCK6TD7K6M9qly0pgXa5P02?= =?us-ascii?Q?wZCUwwP0uzTgfaPlBqF1SSr2X1p18FVNlpXVFYFLd2X6UkdBoVieRQGnyNYy?= =?us-ascii?Q?NV5cXMdDoLyAuby4RDe3rsOz7KT7xAY97qegMRhwHWhpmcNBjPlXJYljcKU1?= =?us-ascii?Q?mMz+7TUean6sz5wmt5oN7KLy0eeJj6FbQNQR6xb4fT0x5NXF5mnXviBpUI0e?= =?us-ascii?Q?z6OBzWsG0/5RUKw00h7bM8wlTNkFks+94Pi87SPwOS0K9a2MybjRsfDAUt+S?= =?us-ascii?Q?ifQw8uChMmeIYK9a4Ohc0vF+dUvSmKnsLxbs0BVChJXprm9gS/dvw7fklR8K?= =?us-ascii?Q?6fNUFDvXElxQpFQMY/RCVjujubmkkTJHscr6t+x1VwWzTVnHZgg/f+/8Wobc?= =?us-ascii?Q?ogkPaZmTPKBE7Kk2ia39/fOtVrbbW6y7+D8TDXR7k+pzqQSt3VfLLMz9Q2bU?= =?us-ascii?Q?VbQcDkKJPILvL08nmGHI/XIJWbDttidH6E+GlJpNBXajRSYMackPuaa6Yn8v?= =?us-ascii?Q?nNsmbuhpBYMU+PDp+FdN5RbQQ5CyP8QNHhXlJkQ3jweNSJM8LVzQ5EaObcNJ?= =?us-ascii?Q?bP3Gu0gN3R0daY0IrgNJ3kUoAEmj/oPweqnSJfDhQmn7bhrefYkKyntJl6Qf?= =?us-ascii?Q?rA=3D=3D?= 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: 8e220f75-0ef7-486b-949d-08de293be95d X-MS-Exchange-CrossTenant-AuthSource: CO6PR10MB5409.namprd10.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 21 Nov 2025 20:24:02.9638 (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: slidGTLevPGDOkd+M82i10cp1wu+zG+XhIZbcKavkl8d3WWt28+tG0E22FnJBi2bCPibRwZy/3EirkIz92gP42CEr4jYgbOrLCSmDxFu9eg= X-MS-Exchange-Transport-CrossTenantHeadersStamped: SA1PR10MB6470 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=2025-11-21_06,2025-11-21_01,2025-10-01_01 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 spamscore=0 mlxlogscore=999 suspectscore=0 malwarescore=0 mlxscore=0 bulkscore=0 phishscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2510240000 definitions=main-2511210155 X-Proofpoint-Spam-Details-Enc: AW1haW4tMjUxMTE1MDAzMiBTYWx0ZWRfX924p7CfNC+Ox WGOu/UO2/lDc96/GDbMhWfi6/kSttNOzzI7u8EIGIwCQr/ifTRNE4rBYcZzzDlWDRAdC2/upCpQ qqQay5ej2HxFc9m/KWafFKUOgmlYx//DuNBYoXiZWDHMO4z/YsqyjTTKjUeI3ZfCW1Y6p4aCOSX fjguFXd8R4CF4TwkC9kFLxXC3b3RD+GSBBQwUeLwN7lGRHzfAlrDQoG60y9C2Q95zRFTHO+EKnj t+NOilCTmxo5dMKunUsfj3FAQL/DClKxJA42hd/9Kxu8qxUMqq+A5Aj/lCn9USfOpWnNOVYnMXP M88FLpyO3T9wAR29HfmSAOATSNfTJ3gdfM27zdDaW7ysx5353jm5KyVCrjPje1fRojdeMiW8Q6I OeGvo526744LCZ7awL7dI9tfgzi8Gw== X-Proofpoint-GUID: 6toqK3udfFIOQT_MheQHxMd1UpPc1GPy X-Proofpoint-ORIG-GUID: 6toqK3udfFIOQT_MheQHxMd1UpPc1GPy X-Authority-Analysis: v=2.4 cv=Rdydyltv c=1 sm=1 tr=0 ts=6920ca6a cx=c_pps a=XiAAW1AwiKB2Y8Wsi+sD2Q==:117 a=XiAAW1AwiKB2Y8Wsi+sD2Q==:17 a=6eWqkTHjU83fiwn7nKZWdM+Sl24=:19 a=z/mQ4Ysz8XfWz/Q5cLBRGdckG28=:19 a=lCpzRmAYbLLaTzLvsPZ7Mbvzbb8=:19 a=xqWC_Br6kY4A:10 a=6UeiqGixMTsA:10 a=GoEa3M9JfhUA:10 a=VkNPw1HP01LnGYTKEx00:22 a=yPCof4ZbAAAA:8 a=zd2uoN0lAAAA:8 a=CZTfYOs-HqEX1FBfxHsA:9 X-Rspamd-Server: rspam12 X-Rspam-User: X-Rspamd-Queue-Id: 6372440011 X-Stat-Signature: q5zgtemnwc46r6ka6xut5rbxa5x9f7ip X-HE-Tag: 1763756667-584300 X-HE-Meta: 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 JZRLpqPK 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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: clear_page_rep() and clear_page_erms() are wrappers around "REP; STOS" variations. Inlining gets rid of an unnecessary CALL/RET (which isn't free when using RETHUNK speculative execution mitigations.) Fixup and rename clear_page_orig() to adapt to the changed calling convention. Also add a comment from Dave Hansen detailing various clearing mechanisms used in clear_page(). Signed-off-by: Ankur Arora Tested-by: Raghavendra K T --- Notes: - s/memzero_page_aligned_unrolled/__clear_pages_unrolled/ - fixup comment to specify x86 insns in the standard ALL CAPS style. arch/x86/include/asm/page_32.h | 6 ++++ arch/x86/include/asm/page_64.h | 50 ++++++++++++++++++++++++---------- arch/x86/lib/clear_page_64.S | 39 ++++++-------------------- 3 files changed, 49 insertions(+), 46 deletions(-) diff --git a/arch/x86/include/asm/page_32.h b/arch/x86/include/asm/page_32.h index 0c623706cb7e..19fddb002cc9 100644 --- a/arch/x86/include/asm/page_32.h +++ b/arch/x86/include/asm/page_32.h @@ -17,6 +17,12 @@ extern unsigned long __phys_addr(unsigned long); #include +/** + * clear_page() - clear a page using a kernel virtual address. + * @page: address of kernel page + * + * Does absolutely no exception handling. + */ static inline void clear_page(void *page) { memset(page, 0, PAGE_SIZE); diff --git a/arch/x86/include/asm/page_64.h b/arch/x86/include/asm/page_64.h index 53f4089333f2..6157bf46590e 100644 --- a/arch/x86/include/asm/page_64.h +++ b/arch/x86/include/asm/page_64.h @@ -40,26 +40,46 @@ extern unsigned long __phys_addr_symbol(unsigned long); #define __phys_reloc_hide(x) (x) -void clear_page_orig(void *page); -void clear_page_rep(void *page); -void clear_page_erms(void *page); -KCFI_REFERENCE(clear_page_orig); -KCFI_REFERENCE(clear_page_rep); -KCFI_REFERENCE(clear_page_erms); +void __clear_pages_unrolled(void *page); +KCFI_REFERENCE(__clear_pages_unrolled); -static inline void clear_page(void *page) +/** + * clear_page() - clear a page using a kernel virtual address. + * @addr: address of kernel page + * + * Switch between three implementations of page clearing based on CPU + * capabilities: + * + * - __clear_pages_unrolled(): the oldest, slowest and universally + * supported method. Zeroes via 8-byte MOV instructions unrolled 8x + * to write a 64-byte cacheline in each loop iteration. + * + * - "REP; STOSQ": really old CPUs had crummy REP implementations. + * Vendor CPU setup code sets 'REP_GOOD' on CPUs where REP can be + * trusted. The instruction writes 8-byte per REP iteration but + * CPUs can internally batch these together and do larger writes. + * + * - "REP; STOSB": CPUs that enumerate 'ERMS' have an improved STOS + * implementation that is less picky about alignment and where + * STOSB (1-byte at a time) is actually faster than STOSQ (8-bytes + * at a time.) + * + * Does absolutely no exception handling. + */ +static inline void clear_page(void *addr) { + u64 len = PAGE_SIZE; /* * Clean up KMSAN metadata for the page being cleared. The assembly call - * below clobbers @page, so we perform unpoisoning before it. + * below clobbers @addr, so we perform unpoisoning before it. */ - kmsan_unpoison_memory(page, PAGE_SIZE); - alternative_call_2(clear_page_orig, - clear_page_rep, X86_FEATURE_REP_GOOD, - clear_page_erms, X86_FEATURE_ERMS, - "=D" (page), - "D" (page), - "cc", "memory", "rax", "rcx"); + kmsan_unpoison_memory(addr, len); + asm volatile(ALTERNATIVE_2("call __clear_pages_unrolled", + "shrq $3, %%rcx; rep stosq", X86_FEATURE_REP_GOOD, + "rep stosb", X86_FEATURE_ERMS) + : "+c" (len), "+D" (addr), ASM_CALL_CONSTRAINT + : "a" (0) + : "cc", "memory"); } void copy_page(void *to, void *from); diff --git a/arch/x86/lib/clear_page_64.S b/arch/x86/lib/clear_page_64.S index a508e4a8c66a..c245b7fc01cd 100644 --- a/arch/x86/lib/clear_page_64.S +++ b/arch/x86/lib/clear_page_64.S @@ -6,30 +6,15 @@ #include /* - * Most CPUs support enhanced REP MOVSB/STOSB instructions. It is - * recommended to use this when possible and we do use them by default. - * If enhanced REP MOVSB/STOSB is not available, try to use fast string. - * Otherwise, use original. + * Zero page aligned region. + * %rdi - dest + * %rcx - length */ - -/* - * Zero a page. - * %rdi - page - */ -SYM_TYPED_FUNC_START(clear_page_rep) - movl $4096/8,%ecx - xorl %eax,%eax - rep stosq - RET -SYM_FUNC_END(clear_page_rep) -EXPORT_SYMBOL_GPL(clear_page_rep) - -SYM_TYPED_FUNC_START(clear_page_orig) - xorl %eax,%eax - movl $4096/64,%ecx +SYM_TYPED_FUNC_START(__clear_pages_unrolled) + shrq $6, %rcx .p2align 4 .Lloop: - decl %ecx + decq %rcx #define PUT(x) movq %rax,x*8(%rdi) movq %rax,(%rdi) PUT(1) @@ -43,16 +28,8 @@ SYM_TYPED_FUNC_START(clear_page_orig) jnz .Lloop nop RET -SYM_FUNC_END(clear_page_orig) -EXPORT_SYMBOL_GPL(clear_page_orig) - -SYM_TYPED_FUNC_START(clear_page_erms) - movl $4096,%ecx - xorl %eax,%eax - rep stosb - RET -SYM_FUNC_END(clear_page_erms) -EXPORT_SYMBOL_GPL(clear_page_erms) +SYM_FUNC_END(__clear_pages_unrolled) +EXPORT_SYMBOL_GPL(__clear_pages_unrolled) /* * Default clear user-space. -- 2.31.1