From patchwork Tue Nov 7 21:57:34 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ankur Arora X-Patchwork-Id: 162784 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a59:aa0b:0:b0:403:3b70:6f57 with SMTP id k11csp544684vqo; Tue, 7 Nov 2023 14:07:47 -0800 (PST) X-Google-Smtp-Source: AGHT+IHS5krv592OChMMn0Jai9UhMDmRhJRGNXOiHs72epxrASILKNdZwUA4qyv4QtsoqL2zDksb X-Received: by 2002:a17:902:d2c6:b0:1cc:e76e:f214 with SMTP id n6-20020a170902d2c600b001cce76ef214mr363153plc.29.1699394867366; Tue, 07 Nov 2023 14:07:47 -0800 (PST) ARC-Seal: i=2; a=rsa-sha256; t=1699394867; cv=pass; d=google.com; s=arc-20160816; b=RI9PHAJDFkq1241oJ81nkNtUc7HyR4smOH14Ix+uRrpdruB38ooayiSVGr8bw7P6C2 Gp9U8ZanssK0XpTHl+z+Q/pgTxQkcaF5zm+qCkYSBAqzo9zA3hxmRM3Hkf6051ZW/i6f wuQ4tWS77X8hf4JO+kIdnIhpj1N7bzxrUpUUnAC3F0cIOoU8QU204BNni1F5BhMj8+FA b8MNzPj/uHyfDjNozb5KBz1lDQv7sRPe4RuEm6+0/eGT+vbFbexQqCIE6VM9JLlBYHkV 5fsFq2Q4okUSWkEfxkvGtaFWljEmRIHojLVrDoZ/kM3YPPYAUraSeZ/gD+NK9UP5L3nR X88Q== 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=yWPCiZxYn64BBGU9hVy0zBTR2Q9Cw9JMNreM2MaUTDs=; fh=nHnEAWNp+qNKUfhTYdiVYwv41cALFixOy2SlfWaTsrM=; b=lGUEyUNB3xWzoTdU06JQWEQIaeS6mviQ/1+Anqp1cREDDrfUFsu4qbQJ7X2oOQIqc5 FmJQ+jhsgTcYfgh+QUZ/jd65ooFcRgaqmgCjW366FckR/Uw/QUi9drAcw7DqUBOEeGp/ 6nJGd4JSE9kKwkAEV54FdxOyCCacDDSDTotJrDmMPGzCiaf8Rhu+zkTYIeAhecr76E1L 1PkaEwk2aSeIT7Rug30EcaQKnjKnSJKfmkOMZnTpWYV0ynISQNOdl+qy9lHcADio0Erv Bym3UV+wyj3LMpWObDvLswAZXVu7uaDKRtdkJTCsdXDeHKrHrCy3LEmLfdA2m/OsMgK2 reXQ== ARC-Authentication-Results: i=2; mx.google.com; dkim=pass header.i=@oracle.com header.s=corp-2023-03-30 header.b=uZ1ERk38; dkim=pass header.i=@oracle.onmicrosoft.com header.s=selector2-oracle-onmicrosoft-com header.b=Xd5gTbJd; 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 23.128.96.32 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 agentk.vger.email (agentk.vger.email. [23.128.96.32]) by mx.google.com with ESMTPS id kq8-20020a170903284800b001c74d844254si633558plb.101.2023.11.07.14.07.47 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 07 Nov 2023 14:07:47 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.32 as permitted sender) client-ip=23.128.96.32; Authentication-Results: mx.google.com; dkim=pass header.i=@oracle.com header.s=corp-2023-03-30 header.b=uZ1ERk38; dkim=pass header.i=@oracle.onmicrosoft.com header.s=selector2-oracle-onmicrosoft-com header.b=Xd5gTbJd; 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 23.128.96.32 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 (depot.vger.email [IPv6:2620:137:e000::3:0]) by agentk.vger.email (Postfix) with ESMTP id 3B87280E5B8C; Tue, 7 Nov 2023 14:07:42 -0800 (PST) X-Virus-Status: Clean X-Virus-Scanned: clamav-milter 0.103.11 at agentk.vger.email Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235566AbjKGWFx (ORCPT + 32 others); Tue, 7 Nov 2023 17:05:53 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38758 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235304AbjKGWFC (ORCPT ); Tue, 7 Nov 2023 17:05:02 -0500 Received: from mx0a-00069f02.pphosted.com (mx0a-00069f02.pphosted.com [205.220.165.32]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A20EE3C00 for ; Tue, 7 Nov 2023 14:01:31 -0800 (PST) Received: from pps.filterd (m0246627.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 3A7LJLaC028111; Tue, 7 Nov 2023 22:00:24 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-2023-03-30; bh=yWPCiZxYn64BBGU9hVy0zBTR2Q9Cw9JMNreM2MaUTDs=; b=uZ1ERk38/99URZZ5LYv10DESAlQ23yaO2R8ecq7LvbQtQk5K2GLNznjwRdIh18mSlckK nvtH11r5DDJZW8iHD5/ZfN5GHV1IEXvRj/YFVQJ7iSntAnif516CaTq4cwx8ZdnTJX5f BBf5FYW5UxEJUM33yrm8R6vrYei2ltdWGTsQlY8Ug7VVvC4DVtLHHy4MYiUDNG2O2VIu X6YL9rcEbO2Bs7Tnvq4N+O6PPItgF3mL1NK9k4UrQlV1QLPIlRhgz4TEWVGH8YVHJXaM DjxnHLIRbL3pOyDs+AmvWOqNAbUzf5Ktgn6bAY4cbeLXUzHhrJ7xQSKNmZ0gJhE+77Ua 0Q== Received: from phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com (phxpaimrmta03.appoci.oracle.com [138.1.37.129]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 3u7w2302da-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 07 Nov 2023 22:00:24 +0000 Received: from pps.filterd (phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com [127.0.0.1]) by phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com (8.17.1.19/8.17.1.19) with ESMTP id 3A7LIgdM011085; Tue, 7 Nov 2023 22:00:23 GMT Received: from nam02-bn1-obe.outbound.protection.outlook.com (mail-bn1nam02lp2040.outbound.protection.outlook.com [104.47.51.40]) by phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com (PPS) with ESMTPS id 3u7w1tskeh-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 07 Nov 2023 22:00:23 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=gKQ3q33yP9U+zqfaYVizMqdEYtYdlWsOFTwhytGWrtcQvqLH/pFI8IwlDgGGqicgO33xJoK5R7y4MgWjTU1Ezp/E/IDHG4Ui5rcHmDRHHFW7GAqu1lRYq55JrQzG8IMo75eHrxe/9q76mMg7HUJSENgoY9iygiq7vvAr/fa0XJ3xS7I2XtSrFtLXU73Zt5ev9O5zSRw8Nc3dN5r/1ssuy2G/RD8li17U2YYY85dfSI4cwe7UWHotmgdH4S6+OwltTIGb9P2H7mhOUl+Wk38Vs1XZWi14sVdORnL8BHu1ATqByzD0zFa5MxYZXxf5fVqZujWzlyasAlYPfdWejbZL6g== 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=yWPCiZxYn64BBGU9hVy0zBTR2Q9Cw9JMNreM2MaUTDs=; b=g1XoODtMWKXxLz7hHAPl/MlVteMx8Lhqfgf6LEMVsyZ2te/R1+p5lWGzyRszXBs934z/VvgA/GqdmgucsaH0VNjD6e3cMC1nVdDZrPXwcoyGtCQl1oBEkdUR6aML6yTrIm/4/wTIPt1aiJrm/uAgBBv+GbI/TD6TJJ33Bl2XSJ7UyUgXVOJgiNEo8VQdiKO6lbr8wKKbNXQHd8gKq5fJiQtRa+VygfPhJDM2NcT/r0YuRyG/vfsV9DYyVLNQ54xeDWEkV4C9QaIip1G1H4m6mcSTFyKYUMF37SSCdi+z/aPPOl89sMbBW3X/N1gIzbP1yefAfZAdLNcwhyJDnGv3Lg== 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=yWPCiZxYn64BBGU9hVy0zBTR2Q9Cw9JMNreM2MaUTDs=; b=Xd5gTbJdXrjIoxcE55BCItx/P/1FmTCTymG2z3l4Y9GK1UlKb/V7gR4KtiW99lXYQPA3z7IsLbyqGi5NetFaCRWDGhz6jRzkQHTekFPlCX2cpNOznLMOKN3uT+JZrDt0OXbETHdEcHsSS5+k8w1zUYnXKDGgqRWPlrSo0GJiTvk= Received: from CO6PR10MB5409.namprd10.prod.outlook.com (2603:10b6:5:357::14) by PH7PR10MB6275.namprd10.prod.outlook.com (2603:10b6:510:211::5) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.6954.27; Tue, 7 Nov 2023 22:00:10 +0000 Received: from CO6PR10MB5409.namprd10.prod.outlook.com ([fe80::1ce3:4a8c:4c99:acea]) by CO6PR10MB5409.namprd10.prod.outlook.com ([fe80::1ce3:4a8c:4c99:acea%7]) with mapi id 15.20.6954.028; Tue, 7 Nov 2023 22:00:10 +0000 From: Ankur Arora To: linux-kernel@vger.kernel.org Cc: tglx@linutronix.de, peterz@infradead.org, torvalds@linux-foundation.org, paulmck@kernel.org, linux-mm@kvack.org, x86@kernel.org, akpm@linux-foundation.org, luto@kernel.org, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, mingo@redhat.com, juri.lelli@redhat.com, vincent.guittot@linaro.org, willy@infradead.org, mgorman@suse.de, jon.grimm@amd.com, bharata@amd.com, raghavendra.kt@amd.com, boris.ostrovsky@oracle.com, konrad.wilk@oracle.com, jgross@suse.com, andrew.cooper3@citrix.com, mingo@kernel.org, bristot@kernel.org, mathieu.desnoyers@efficios.com, geert@linux-m68k.org, glaubitz@physik.fu-berlin.de, anton.ivanov@cambridgegreys.com, mattst88@gmail.com, krypton@ulrich-teichert.org, rostedt@goodmis.org, David.Laight@ACULAB.COM, richard@nod.at, mjguzik@gmail.com, Ankur Arora Subject: [RFC PATCH 48/86] rcu: handle quiescent states for PREEMPT_RCU=n Date: Tue, 7 Nov 2023 13:57:34 -0800 Message-Id: <20231107215742.363031-49-ankur.a.arora@oracle.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20231107215742.363031-1-ankur.a.arora@oracle.com> References: <20231107215742.363031-1-ankur.a.arora@oracle.com> X-ClientProxiedBy: MW4PR03CA0308.namprd03.prod.outlook.com (2603:10b6:303:dd::13) To CO6PR10MB5409.namprd10.prod.outlook.com (2603:10b6:5:357::14) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: CO6PR10MB5409:EE_|PH7PR10MB6275:EE_ X-MS-Office365-Filtering-Correlation-Id: e6b8597a-d11e-4e11-a035-08dbdfdce967 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: pE+vNLVbtC+hhLa2LbqKbkDTmGtgLzkN0Y4OHg0UQEG6pFYnyEyGNG6JCIGv+X13VvX6aG4M/rROZt7ueE3GXP1rq43zu31nFHNELQwVgwY8finHUrb7/diVLbsEHAfpXoJmU0UFhO/np9RinRyJi4sw04H+nK05M5ASFbJ8DBH7D9voGQ24d9W/WFdorVnyHXV2B9s3lwyuHuzv9LcSJ+PzYxSuSajl4Iuo/zfLe7SvSMLkDkMs9I4p1dsegBehGOGCTJwbpnNCd7LJOHOZq4QElywvV77e8rO66SwYpfFDCYcPVvRQcypbFpxmgdym2KPxOTHWq7EmtmjmEgXOt/qr8aS/sDEMmlw9njfKrvU/6RCUBz0Yv5I7+BhWUmzNK4eyHt3dl0tlR/EstKHlrMwK9M7oRa1uqEvHoN0EwmKDEvKwJE0nfZ+sOwWGDoKzLX20I9C2bfX23cWCK0FQbhJJR4MQIRaZalsaMUkZINcE1yQ4qC02ZiqCRg1bgwnitAeP0OYXUUp83EPZHU0vsHQqi1CR30Iw+mA/x0meMI7GTgIrMxY2Ppx512UEMdz+ 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:(13230031)(366004)(376002)(396003)(39860400002)(346002)(136003)(230922051799003)(64100799003)(451199024)(186009)(1800799009)(66476007)(6666004)(38100700002)(6916009)(6506007)(316002)(66556008)(36756003)(5660300002)(7416002)(7406005)(41300700001)(66946007)(6512007)(103116003)(1076003)(8936002)(8676002)(4326008)(26005)(6486002)(107886003)(2616005)(2906002)(83380400001)(86362001)(478600001);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: e6b8597a-d11e-4e11-a035-08dbdfdce967 X-MS-Exchange-CrossTenant-AuthSource: CO6PR10MB5409.namprd10.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 07 Nov 2023 22:00:10.6261 (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: soL3MN/jDK6mPZQ9dciYTHAzOtsz300cRhBbkXd+UJele+63v3Nm60qBh61AzXZWYLDr+EROaU+sHxJQnBn9PQxrV8w/Ux8EKvzG9Uoy+F4= X-MS-Exchange-Transport-CrossTenantHeadersStamped: PH7PR10MB6275 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.272,Aquarius:18.0.987,Hydra:6.0.619,FMLib:17.11.176.26 definitions=2023-11-07_13,2023-11-07_01,2023-05-22_02 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 spamscore=0 phishscore=0 suspectscore=0 malwarescore=0 mlxlogscore=817 bulkscore=0 mlxscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2311060000 definitions=main-2311070182 X-Proofpoint-GUID: OjjEIw7rfFh7J34Km8p3BEoymEXglLjZ X-Proofpoint-ORIG-GUID: OjjEIw7rfFh7J34Km8p3BEoymEXglLjZ Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-Greylist: Sender passed SPF test, not delayed by milter-greylist-4.6.4 (agentk.vger.email [0.0.0.0]); Tue, 07 Nov 2023 14:07:42 -0800 (PST) X-Spam-Status: No, score=-0.9 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,T_SCC_BODY_TEXT_LINE autolearn=unavailable autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on agentk.vger.email X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: 1781944672658639033 X-GMAIL-MSGID: 1781944672658639033 cond_resched() is used to provide urgent quiescent states for read-side critical sections on PREEMPT_RCU=n configurations. This was necessary because lacking preempt_count, there was no way for the tick handler to know if we were executing in RCU read-side critical section or not. An always-on CONFIG_PREEMPT_COUNT, however, allows the tick to reliably report quiescent states. Accordingly, evaluate preempt_count() based quiescence in rcu_flavor_sched_clock_irq(). Suggested-by: Paul E. McKenney Signed-off-by: Ankur Arora --- kernel/rcu/tree_plugin.h | 3 ++- kernel/sched/core.c | 15 +-------------- 2 files changed, 3 insertions(+), 15 deletions(-) diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index f87191e008ff..618f055f8028 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -963,7 +963,8 @@ static void rcu_preempt_check_blocked_tasks(struct rcu_node *rnp) */ static void rcu_flavor_sched_clock_irq(int user) { - if (user || rcu_is_cpu_rrupt_from_idle()) { + if (user || rcu_is_cpu_rrupt_from_idle() || + !(preempt_count() & (PREEMPT_MASK | SOFTIRQ_MASK))) { /* * Get here if this CPU took its interrupt from user diff --git a/kernel/sched/core.c b/kernel/sched/core.c index bf5df2b866df..15db5fb7acc7 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -8588,20 +8588,7 @@ int __sched _cond_resched(void) preempt_schedule_common(); return 1; } - /* - * In preemptible kernels, ->rcu_read_lock_nesting tells the tick - * whether the current CPU is in an RCU read-side critical section, - * so the tick can report quiescent states even for CPUs looping - * in kernel context. In contrast, in non-preemptible kernels, - * RCU readers leave no in-memory hints, which means that CPU-bound - * processes executing in kernel context might never report an - * RCU quiescent state. Therefore, the following code causes - * cond_resched() to report a quiescent state, but only when RCU - * is in urgent need of one. - */ -#ifndef CONFIG_PREEMPT_RCU - rcu_all_qs(); -#endif + return 0; } EXPORT_SYMBOL(_cond_resched);