From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from BYAPR05CU005.outbound.protection.outlook.com (mail-westusazon11010055.outbound.protection.outlook.com [52.101.85.55]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B4447DF76 for ; Tue, 6 Jan 2026 08:42:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=52.101.85.55 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767688934; cv=fail; b=hWn9pU+ml2CLslht/3loH3yXdfsi4wLB8cXEkY7TxrE1L6JCz6B4Qfx1jRZWHsSQXeMU955XLkGHBUV9rxvi26L8lHMCXPjlIc6imKlootY5T7nN1KTt+t8gylfXThksvf8U/U3ztsL7zosvN83abtDpPcsX5lRo3w2iWuc/CNo= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767688934; c=relaxed/simple; bh=DTuTS2GUG0rGgKeOn9BJEfGMx9sg6l8frblzuBqkNKw=; h=Message-ID:Date:MIME-Version:Subject:To:CC:References:From: In-Reply-To:Content-Type; b=fz1/DOF8JOabTvm7pOeLCOzgfdjzdq0fbBTMAawrjSqnzuxzEBki/WERFWtvoDrkAns9W2V4aO4WMJ+kZge3Rb+xpiDXyynpcqQEsKjiwMN544Cr5Jx/q7SYAYTc4Qq50Eso5BLuvg08fEbf0MnQIXz2GikxWbCoDUfr9HxJENA= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amd.com; spf=fail smtp.mailfrom=amd.com; dkim=pass (1024-bit key) header.d=amd.com header.i=@amd.com header.b=z2VkvJvF; arc=fail smtp.client-ip=52.101.85.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amd.com Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=amd.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=amd.com header.i=@amd.com header.b="z2VkvJvF" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=RoM72yCtwAU0I3bCSkIE2K9h8FEFqiCe/SkbtGDwpLiBRmY729Ku/7+RSEeA+Aus++8L1o4CBVFFcel4AKkYk5mEBFCAvAh1z5696O3altyPeBNhEaUf0hdV8HwUHAwMZfTWODTvbrKr5K4gF6JABYzfyh169pwIsvOzHYxNUx+Ve/5w0OllXixbMngVJ//Xqj+xItNvUGWYV3kZalxd/6Hh7HE/kqUb18YY8GVdZYKq2TTznjZaDs+ovacklglMuSFZuxPmPvNv1SWZ+zJRq80gRTcVYYX3TjyJYOFpulGZ+5lPN1+JAIeiICyn+lO0GygNGcZ/QHyWSesBZUJNpg== 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=SA9cR4z/azquyrk6CDEqMNCwkijjlQ7F1fWyPcvk/GU=; b=vrU/3dUwEeDtWkCIeQkk7BE7cWcPebY4T0UbyVqkNR97kGHVP2mS0ePEKTvfBB8Vumwd+6GI0JvgzGjwFpPgIErj/fnxXvOKLO+ZxkuJJP6kya6VPmNMVLlA+bZApRm5eqwNxXeeguegwdcrNYGRPcHQedbwEtObvCKFUF/Zoyd392ameR9aCXj035BD9qzKZ6KGOcAdHiJqDu9MTItkOFEEROgN2nFKIKY6af8jhtIFDXERmz6Qk9yJRwAg3dKlKQ+VGde92GFCMiylwSJ6KVNkZVXgvbuu8C18NUjxVEEQjLB9cw0j4WWFvTScYcGRWcOSaEw7q0rKlls4EqB5aA== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass (sender ip is 165.204.84.17) smtp.rcpttodomain=huawei.com smtp.mailfrom=amd.com; dmarc=pass (p=quarantine sp=quarantine pct=100) action=none header.from=amd.com; dkim=none (message not signed); arc=none (0) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amd.com; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=SA9cR4z/azquyrk6CDEqMNCwkijjlQ7F1fWyPcvk/GU=; b=z2VkvJvFsmu8kScZ4U3Hlt+IaF3aoMdEZyXJ9Yqxcf7Pvy695wE9jw+QVTUQM+BoLVlKJezkEawImbq9y2rSeDyrZgxrnQ8ixc3rPL0d3a0piV+5XqAvgJSHMUhwd8ydo7+c9AebOPKfZI0nAYH2Ae/GXmaM/RxX+3brvimtlso= Received: from BL0PR02CA0124.namprd02.prod.outlook.com (2603:10b6:208:35::29) by SA3PR12MB9158.namprd12.prod.outlook.com (2603:10b6:806:380::22) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9478.4; Tue, 6 Jan 2026 08:42:06 +0000 Received: from BL6PEPF0001AB4C.namprd04.prod.outlook.com (2603:10b6:208:35:cafe::9a) by BL0PR02CA0124.outlook.office365.com (2603:10b6:208:35::29) with Microsoft SMTP Server (version=TLS1_3, cipher=TLS_AES_256_GCM_SHA384) id 15.20.9478.4 via Frontend Transport; Tue, 6 Jan 2026 08:42:08 +0000 X-MS-Exchange-Authentication-Results: spf=pass (sender IP is 165.204.84.17) smtp.mailfrom=amd.com; dkim=none (message not signed) header.d=none;dmarc=pass action=none header.from=amd.com; Received-SPF: Pass (protection.outlook.com: domain of amd.com designates 165.204.84.17 as permitted sender) receiver=protection.outlook.com; client-ip=165.204.84.17; helo=satlexmb08.amd.com; pr=C Received: from satlexmb08.amd.com (165.204.84.17) by BL6PEPF0001AB4C.mail.protection.outlook.com (10.167.242.70) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9499.1 via Frontend Transport; Tue, 6 Jan 2026 08:42:04 +0000 Received: from satlexmb08.amd.com (10.181.42.217) by satlexmb08.amd.com (10.181.42.217) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.17; Tue, 6 Jan 2026 02:42:01 -0600 Received: from [10.136.46.19] (10.180.168.240) by satlexmb08.amd.com (10.181.42.217) with Microsoft SMTP Server id 15.2.2562.17 via Frontend Transport; Tue, 6 Jan 2026 02:41:59 -0600 Message-ID: <077e8b78-f526-497b-b651-50a4e4fbef5e@amd.com> Date: Tue, 6 Jan 2026 14:11:57 +0530 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [RESEND] sched/rt: Skip currently executing CPU in rto_next_cpu() To: Chen Jinghuang , , , , CC: , , , , , References: <20260105034012.3196947-1-chenjinghuang2@huawei.com> Content-Language: en-US From: K Prateek Nayak In-Reply-To: <20260105034012.3196947-1-chenjinghuang2@huawei.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: BL6PEPF0001AB4C:EE_|SA3PR12MB9158:EE_ X-MS-Office365-Filtering-Correlation-Id: 1b5ce845-8e6c-4095-ddb2-08de4cff7812 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|7416014|82310400026|1800799024|36860700013; X-Microsoft-Antispam-Message-Info: =?utf-8?B?cGcwMGJ1QjhKaXdxM1pHZ3FVSHJ2TXRybTVtdnM0SU5QNmNhNDJYQ2p5RUlD?= =?utf-8?B?dzBsZnNsVDRPdFlLMXJnZUM5V2o0TFRzM0szeFprbk5razZGYkFtMkIvd3ZM?= =?utf-8?B?SVZyUXdvdGpNUm53amFtZTZmU2RyRmFPaVFmajk3QWFPTE5BTXpmK0FhNFZI?= =?utf-8?B?TXh4NkgvUWdKZ0l4TUozUHU3bTNFZ3FxYTRobnpiaXYwVVZjMFIzWkF1WFZ2?= =?utf-8?B?UHN5dSs3bFRUcmZNaTdJMzFYRHJudUF2Q2tsWFE1K3ZCd01ieDB2cVhBZjdB?= =?utf-8?B?UTVsV2IrNzE5cFlxT29CdTVMemN3Y29PREdTdjZxc3gyQ1VENnVOQm85L1dR?= =?utf-8?B?cWk1SDVvODZ3RWxXVHZHUEpHc1V4YTcxYW82L29JQ3RUVURPSE9UYkJ4UWFS?= =?utf-8?B?dUZZbk8rNytrVUxpTEFtMHhmRnR4dFJXT1dHNzlUTEVUclBvRTBwaURJbDBD?= =?utf-8?B?RzlJZEIrYmhta201RmEvc1NTbzhVMzZHaTFVSFJEeFpxYzEzRjAzQTRZbkNR?= =?utf-8?B?UWEvQmFwYnROaHc1SWQzOTRNYUEvUjFQQU5rNmZiSFZ6YnB6QzVobGU2SXhE?= =?utf-8?B?ajRFbkZlMkpGVlRrdFlKbUpTSitSMUdPTlNDWVh3MFBhdGl6c0tOcEphWHNE?= =?utf-8?B?dDV3U1FmRXZSV2RQcGpLemp6amJVWXhSMmNqRUU2ZUk1VzdOLzNFSDZid1g4?= =?utf-8?B?cThpRktSTlVzaXpNeW9SbVhmTDltZWZPWWlickV4YTN2Nnk1UU51Zis0M3RG?= =?utf-8?B?bnF3UGovLzFQN1M5ZmVYZlozdmxHY3dqQVAwNVFaM2hEQzhETWp0eU8ycm5N?= =?utf-8?B?VUdLQ25sSW11c29vK1kvNXJnRWpub2hxT3l5WUdsa3dRUmNHVUtJcTE5ZThv?= =?utf-8?B?V0RwdS96anNrNzlTbjdiYjYzVUpSdHdUZEFvYndlTW4rc2hBVzJyVjI3TzQv?= =?utf-8?B?ZmpLWXUrcC95MUU0Zjgwcnd4RkZ2eVBCN1hSeUgrQVpCYU5PV2dZUGt5aklF?= =?utf-8?B?bmYvWGVxTHpHZFoweGRKTVVSSlFyQjhDQTRCQS9NbFp3aUh3dWJRRTBqT3RH?= =?utf-8?B?UkY0dnZNWHFvOElwWXJMd3N1dEtBQzJMMmJSWHc5alV3M0g5bzZIRTVxTjNB?= =?utf-8?B?QjNScFVmSndWYjIwQnJ5V3BTR0dHdk5OVk1xQ2ZYeTBwUUZ0MlpOVjhhWDIz?= =?utf-8?B?VnhOMjdDeUVEekJKYUJoalZFdlZJSzIybDFaUVZ4R3A3OUE4Q0d1Z1FLRmVL?= =?utf-8?B?UGFCY0NZaFBET0FOb01VdUdSR01GWVowVjVtWTkyQTE4ditqNzJ1ekZ0WmRI?= =?utf-8?B?OGE5WVdQTHBIdWxzeW9pOUczL1pXbm8zUjMxMDNxSldUVFFOd0FnU3VBOFhG?= =?utf-8?B?dVovdVU5YjNMNlNtcHJIb1lXYnNhWlJHSkUxRGZhN2xtd09KcmRyVmpLdXZ5?= =?utf-8?B?bHgwQ1BGekE4Z3M4NGZaL25IaHQ1TUphVWJ1N0NnWmlXNDE4TUsvMnp3Y281?= =?utf-8?B?SGY0RHh5U1Vma05BTjdDdmttQitTeURLUmF0SnFzeHdDREVObWREQWNBVVBZ?= =?utf-8?B?cjkxcmF0VlpsdmlnMWo0V2g3VFZPRUhpVmM5cDc3VE1IMzkyT3hNZHlZMmgy?= =?utf-8?B?eXRSUUZDcVJIamduRSs3c3dLVTY0S29oREY4clN6ejlvS1JNekwycCtRS1o1?= =?utf-8?B?Z0N1WU45VW1QUGtpRkVDZWI0UlBWSlIzaEc2cjlUeEgvNjVscktaajNldko5?= =?utf-8?B?Q0NjVmpubWhpendvNUt2VUV6L0JmTkhwYVhTZzQ0enRxR2k1WkxmekZ2VG1a?= =?utf-8?B?ZHJsZkpDbTRkbGtIV3VXQmN6VU03aUx2SXZieGovcW9RN01QeXpoSjZjSzZW?= =?utf-8?B?bmlnV3JWa2NPMTZFeVA2NmtJaFZSWlE5SWU2WE15V1VSRFJHQlEzNnNGNllz?= =?utf-8?B?aU01QmRDbjB0ZGtSczJlUUVWSDJSMVJGcXZCREJ1Z0R5VnIxODBWazZ5Uld6?= =?utf-8?B?QXFLbUZ3ZFBzUytoZXZ0WVB0L3JIK2VPY0UwNUxqc2FwUUtZK2JWWDVxelJk?= =?utf-8?B?RUprSHk0MWRKQVptM2Nhb3QrNFk2QWVXbkxGQT09?= X-Forefront-Antispam-Report: CIP:165.204.84.17;CTRY:US;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:satlexmb08.amd.com;PTR:InfoDomainNonexistent;CAT:NONE;SFS:(13230040)(376014)(7416014)(82310400026)(1800799024)(36860700013);DIR:OUT;SFP:1101; X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 06 Jan 2026 08:42:04.7636 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 1b5ce845-8e6c-4095-ddb2-08de4cff7812 X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=3dd8961f-e488-4e60-8e11-a82d994e183d;Ip=[165.204.84.17];Helo=[satlexmb08.amd.com] X-MS-Exchange-CrossTenant-AuthSource: BL6PEPF0001AB4C.namprd04.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: SA3PR12MB9158 Hello Chen, Steve, On 1/5/2026 9:10 AM, Chen Jinghuang wrote: > @@ -2118,10 +2119,13 @@ static int rto_next_cpu(struct root_domain *rd) > */ > for (;;) { > > - /* When rto_cpu is -1 this acts like cpumask_first() */ > - cpu = cpumask_next(rd->rto_cpu, rd->rto_mask); > + do { > + /* When rto_cpu is -1 this acts like cpumask_first() */ > + cpu = cpumask_next(rd->rto_cpu, rd->rto_mask); > > - rd->rto_cpu = cpu; > + rd->rto_cpu = cpu; > + /* Do not send IPI to self */ > + } while (cpu == this_cpu); nit. Since we are already within an infinite for-loop, can't we simply do: /* Do not send IPI to self */ if (cpu == this_cpu) continue; here and go evaluate cpumask_next() again instead of adding another do-while? Was the nested loop intentional to highlight these bits explicitly? > > if (cpu < nr_cpu_ids) > return cpu; -- Thanks and Regards, Prateek