From patchwork Mon Mar 6 16:22:28 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric DeVolder X-Patchwork-Id: 64918 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a5d:5915:0:0:0:0:0 with SMTP id v21csp1941470wrd; Mon, 6 Mar 2023 08:36:05 -0800 (PST) X-Google-Smtp-Source: AK7set+1SyXKoPiGf1rxH05FV43rOd6lRC9Q9wIJ9TNo6ERWQylsIHGM9xRU1sQ44JAUKpbQWdXl X-Received: by 2002:a05:6a21:6da0:b0:cc:50cd:e2e1 with SMTP id wl32-20020a056a216da000b000cc50cde2e1mr12766142pzb.0.1678120564813; Mon, 06 Mar 2023 08:36:04 -0800 (PST) ARC-Seal: i=2; a=rsa-sha256; t=1678120564; cv=pass; d=google.com; s=arc-20160816; b=QGdXjC/vEo/7Le5q2Isy8Vg1vC46HCS66LeDRpe0Ius8+fIu068Ww9f6GbZ0H7cdK1 bnZ/3wrpEbj9i2IixeAfckcUdS6D3WN411oBGd6vefL7oLp9kYknp5t61TY/4HV2J6YL kARjNuoFoY7uBFmZz8c3Z0AP/NFjt+Cqv7X7k69mf63U9N3DA8TA+Xn9kgN5jDw4KIay I3ndvZLDmRRVysmFjTakDNpRCtU1tMmBErS5dlP9W+CZb2rqRqrH1+KcfWiEq6cDT1cK /jXQBE76XH8xgQPYGoT2T1kuMJadb6TgvHKTTfUWmTAEvBpP0DYqm1pIDi5JI7L+IafN 0ahA== ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:mime-version:content-transfer-encoding :references:in-reply-to:message-id:date:subject:cc:to:from :dkim-signature:dkim-signature; bh=TMa2NJx33yIc4VOtYE8TqZmk60QFOgD8Z7Kqzm24ldY=; b=asyQ/BiKqc8vHjVv9PjPbfcF5wSyOaySVC65nXMhCwdlJQNXjSKGRE7SQ+wh1Ke8Y4 FMLOGlSKvwB3wsneL0rVwxjH0tYEe0Iy4O5RmJWhxb7PpJ7Q7nyGM1Cfcq0ctQSnf+7/ d4Mi9Fsga3ighpBytcfFWYMi5K0xqhJ05BXFfWjsaSxp7H1X8nTDAybVb2n7BcgxczvB 1wyUTw3Yc6Jmmwti4BBt3bIr3ehMjvtkJi3rM4BTlM5pMu+F/Z73Z2tkoC/o1zLaQB2f R4SYOrMOGA13ch2KUUzrocFgM3ZlV+KdVLYiL54P80XVEQ6xzc9WDWaFyfDqPJjvUBwY uizw== ARC-Authentication-Results: i=2; mx.google.com; dkim=pass header.i=@oracle.com header.s=corp-2022-7-12 header.b=G5pi+9Wn; dkim=pass header.i=@oracle.onmicrosoft.com header.s=selector2-oracle-onmicrosoft-com header.b=gTEI+Yag; arc=pass (i=1 spf=pass spfdomain=oracle.com dkim=pass dkdomain=oracle.com dmarc=pass fromdomain=oracle.com); spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=oracle.com Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id n6-20020a634006000000b004fbb641a508si9518194pga.337.2023.03.06.08.35.52; Mon, 06 Mar 2023 08:36:04 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@oracle.com header.s=corp-2022-7-12 header.b=G5pi+9Wn; dkim=pass header.i=@oracle.onmicrosoft.com header.s=selector2-oracle-onmicrosoft-com header.b=gTEI+Yag; arc=pass (i=1 spf=pass spfdomain=oracle.com dkim=pass dkdomain=oracle.com dmarc=pass fromdomain=oracle.com); spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=oracle.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230312AbjCFQ0M (ORCPT + 99 others); Mon, 6 Mar 2023 11:26:12 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57066 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230124AbjCFQZk (ORCPT ); Mon, 6 Mar 2023 11:25:40 -0500 Received: from mx0b-00069f02.pphosted.com (mx0b-00069f02.pphosted.com [205.220.177.32]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B5EEA38B7C for ; Mon, 6 Mar 2023 08:24:42 -0800 (PST) Received: from pps.filterd (m0246630.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 326CxFvT031462; Mon, 6 Mar 2023 16:23:16 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : content-transfer-encoding : content-type : mime-version; s=corp-2022-7-12; bh=TMa2NJx33yIc4VOtYE8TqZmk60QFOgD8Z7Kqzm24ldY=; b=G5pi+9WnJnqHD6ZXpdoEf+pOOASWbl3NiQN2REyDkkOmXytYmB6EupjxmTRlSOtYZChq Fe/g/PjuhG7H4u+5e5iZaZqNai8TbtW/g/BHhrF9N6PiGPnXc8EG/OmZ1NxHthFKK0+P qwpNayO1e1qgDi5yHVHZWutv5Z6Q7Gfq9hfLkqiWRAVzcIX/CkDkBGmErGLcO30XYoCx +Q71FY/sQJeU1zXUHGQZhG5MmJeMSRZPVRCcyUGkdKQbp+FKXq0avPCqUEjM9wz0RfmY Nbu38m8gmwkApPH9ypXkYppishW4ea4aL0sxfRxJ939WviK6dZLLAp+2rB9g+fCGuWWi iw== Received: from iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com (iadpaimrmta02.appoci.oracle.com [147.154.18.20]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 3p4180ua5j-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 06 Mar 2023 16:23:16 +0000 Received: from pps.filterd (iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com [127.0.0.1]) by iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com (8.17.1.5/8.17.1.5) with ESMTP id 326G50X7026894; Mon, 6 Mar 2023 16:23:16 GMT Received: from nam12-mw2-obe.outbound.protection.outlook.com (mail-mw2nam12lp2046.outbound.protection.outlook.com [104.47.66.46]) by iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com (PPS) with ESMTPS id 3p4u1dq6n9-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 06 Mar 2023 16:23:15 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=coLXWh+jLpuGw5ayQws+70TLdatPujd5jvb+yEboChoz6KqtJt+8Xd1zFp1Lxk/FxRmUoKaFi/E0T8YnUSVrCI7jHAWZyWcch8FvFGIrbZjrLBtrWc60DTJ/zca0qZXZ6OaLKURjwu4saGTHtEAmXxp8gcLIhBGc13/UWC0q4aJiZJtzA7X+eYVE/nuD8+/edtUgNUB/6HK6dNs9502OKXZzFfvNFjIm9n3ClfHsFDuzq7R2W3g58eA3vdZeclEAFPBW71goPaEXgu35c2IIZH0oK3/l2GXNOeiZpolnpP3CZUGfO64WCH2M5PMoVMQJh+bB2pMtBGxdf81l4S4uTg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; 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=TMa2NJx33yIc4VOtYE8TqZmk60QFOgD8Z7Kqzm24ldY=; b=BW6WSJ0k0Uzqbiq8VOwdSpQmHiy9Dk0HL39VjSZKTG2/bYk4uvN/Pn1YlbSAMCLYNmjXwd8+S9plciYQZEIZXaBoVPN6crnkbVAKiwcQNr86aCVKUEZT+rf3u+JFGlXVK4YLj3eVWLx9fZ9Tv7GrPAYb2PJijdwkpXDH4w8I4395TxFob2ZZq0dBup/dM4KchrB4lGSwQ7jXZal0GDg8I2Y5F8KFT/4Kh7+S/KRKFS7OES0ILNdr6q/aE1mUrgxA0Q71wlT9Pd1pZwyK8sEq9YB+i/CF58WdU4y50q6Zy+s0hWthuOYNOsloy9CG/iGfU4KA7N+/+FcZYqlncTNnsA== 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=TMa2NJx33yIc4VOtYE8TqZmk60QFOgD8Z7Kqzm24ldY=; b=gTEI+YagtEL2JaITbebpn9YvNlrPmPl2wyew9m4hCyuw0kPolBny90twPuj6GgS37qj5GfvaKmJFfdCnEGrIuMqciytZfDB2xluSWja7FtZrRTl0xdza3gPzF3EBtqMxarlj9L+Z8L9/D2b3vBLN6CWVhnx7O1xsBfLjY8Umo3U= Received: from CO1PR10MB4531.namprd10.prod.outlook.com (2603:10b6:303:6c::22) by PH7PR10MB6530.namprd10.prod.outlook.com (2603:10b6:510:201::7) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.6156.28; Mon, 6 Mar 2023 16:23:13 +0000 Received: from CO1PR10MB4531.namprd10.prod.outlook.com ([fe80::671e:6486:6996:c38]) by CO1PR10MB4531.namprd10.prod.outlook.com ([fe80::671e:6486:6996:c38%8]) with mapi id 15.20.6156.028; Mon, 6 Mar 2023 16:23:13 +0000 From: Eric DeVolder To: linux-kernel@vger.kernel.org, x86@kernel.org, kexec@lists.infradead.org, ebiederm@xmission.com, dyoung@redhat.com, bhe@redhat.com, vgoyal@redhat.com Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, nramas@linux.microsoft.com, thomas.lendacky@amd.com, robh@kernel.org, efault@gmx.de, rppt@kernel.org, david@redhat.com, sourabhjain@linux.ibm.com, konrad.wilk@oracle.com, boris.ostrovsky@oracle.com, eric.devolder@oracle.com Subject: [PATCH v19 7/7] x86/crash: optimize cpu changes Date: Mon, 6 Mar 2023 11:22:28 -0500 Message-Id: <20230306162228.8277-8-eric.devolder@oracle.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20230306162228.8277-1-eric.devolder@oracle.com> References: <20230306162228.8277-1-eric.devolder@oracle.com> X-ClientProxiedBy: LO4P123CA0076.GBRP123.PROD.OUTLOOK.COM (2603:10a6:600:190::9) To CO1PR10MB4531.namprd10.prod.outlook.com (2603:10b6:303:6c::22) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: CO1PR10MB4531:EE_|PH7PR10MB6530:EE_ X-MS-Office365-Filtering-Correlation-Id: f3d214e3-49c5-4c58-dfe9-08db1e5f1530 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:CO1PR10MB4531.namprd10.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230025)(346002)(396003)(136003)(376002)(39860400002)(366004)(451199018)(66946007)(66476007)(5660300002)(4326008)(66556008)(41300700001)(7416002)(8936002)(8676002)(86362001)(36756003)(6486002)(478600001)(1076003)(6512007)(186003)(26005)(107886003)(6506007)(6666004)(2616005)(2906002)(316002)(38100700002)(83380400001);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: 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 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: f3d214e3-49c5-4c58-dfe9-08db1e5f1530 X-MS-Exchange-CrossTenant-AuthSource: CO1PR10MB4531.namprd10.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 06 Mar 2023 16:23:13.2276 (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: fol9016Zr57xA03kCyhP8Prbljwit4J1TILAcMNHfZlqGh099HEs/vJeIZP2++ceaxDZd9v5pP7dRvKtz2YgdaRgcmbgcLy7fBO7dHLnpG8= X-MS-Exchange-Transport-CrossTenantHeadersStamped: PH7PR10MB6530 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.219,Aquarius:18.0.942,Hydra:6.0.573,FMLib:17.11.170.22 definitions=2023-03-06_10,2023-03-06_01,2023-02-09_01 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 mlxscore=0 phishscore=0 bulkscore=0 adultscore=0 suspectscore=0 spamscore=0 mlxlogscore=999 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2212070000 definitions=main-2303060145 X-Proofpoint-ORIG-GUID: 5ieTIlNYOlekrNhT-pNfW7FgT5wQo6KA X-Proofpoint-GUID: 5ieTIlNYOlekrNhT-pNfW7FgT5wQo6KA X-Spam-Status: No, score=-2.8 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_LOW, RCVD_IN_MSPIKE_H2,SPF_HELO_NONE,SPF_NONE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1759636949610816584?= X-GMAIL-MSGID: =?utf-8?q?1759636949610816584?= This patch is dependent upon the patch 'crash: change crash_prepare_elf64_headers() to for_each_possible_cpu()'. With that patch, crash_prepare_elf64_headers() writes out an ELF cpu PT_NOTE for all possible cpus, thus further cpu changes to the elfcorehdr are not needed. This change works for kexec_file_load() and kexec_load() syscalls. For kexec_file_load(), crash_prepare_elf64_headers() is utilized directly and thus all ELF cpu PT_NOTEs are in the elfcorehdr already. This is the kimage->file_mode term. For kexec_load() syscall, one cpu or memory change will cause the elfcorehdr to be updated via crash_prepare_elf64_headers() and at that point all ELF cpu PT_NOTEs are in the elfcorehdr. This is the kimage->elfcorehdr_updated term. This code is intentionally *NOT* hoisted into crash_handle_hotplug_event() as it would prevent the arch-specific handler from running for cpu changes. This would break PPC, for example, which needs to update other information besides the elfcorehdr, on cpu changes. Signed-off-by: Eric DeVolder Reviewed-by: Sourabh Jain --- arch/x86/kernel/crash.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c index c9aaec9de775..82ea2b1bdc61 100644 --- a/arch/x86/kernel/crash.c +++ b/arch/x86/kernel/crash.c @@ -471,6 +471,16 @@ void arch_crash_handle_hotplug_event(struct kimage *image) unsigned long mem, memsz; unsigned long elfsz = 0; + /* As crash_prepare_elf64_headers() has already described all + * possible cpus, there is no need to update the elfcorehdr + * for additional cpu changes. This works for both kexec_load() + * and kexec_file_load() syscalls. + */ + if ((image->file_mode || image->elfcorehdr_updated) && + ((image->hp_action == KEXEC_CRASH_HP_ADD_CPU) || + (image->hp_action == KEXEC_CRASH_HP_REMOVE_CPU))) + return; + /* * Create the new elfcorehdr reflecting the changes to CPU and/or * memory resources.