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Wed, 8 Jan 2025 21:14:45 +0000 Date: Wed, 8 Jan 2025 21:14:45 +0000 (GMT) From: Aaron Tomlin To: oleg@redhat.com, frederic@kernel.org, peterz@infradead.org cc: nick.lange@gmail.com, seun.ewulomi@gmail.com, mtosatti@redhat.com, linux-kernel@vger.kernel.org Subject: Re: [RFC PATCH 0/1] sched/isolation: Warn when maxcpus= is specified with nohz_full= or isolcpus= In-Reply-To: Message-ID: References: Content-Type: text/plain; charset=US-ASCII X-ClientProxiedBy: LO2P265CA0110.GBRP265.PROD.OUTLOOK.COM (2603:10a6:600:c::26) To CWLP123MB3523.GBRP123.PROD.OUTLOOK.COM (2603:10a6:400:70::10) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: CWLP123MB3523:EE_|LO0P123MB6220:EE_ X-MS-Office365-Filtering-Correlation-Id: c41343d7-fbf4-4997-5fec-08dd30297a27 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|366016|1800799024|376014; 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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?NchODl2MmuitYJ8z3u5Cx2o1UFs7dO8vvbRpeyqabI2Y+l4Xd3dsNJNrDBJx?= =?us-ascii?Q?ibQKnMGkjG98e6cNQN8rv+jbO8c+OnDmmqlNku8/CDRMaUmMF23ybZZUMnX7?= =?us-ascii?Q?rD7pPIJ6HTL9TspQK9gIEendYc+gg7JWrr1N5k3/j/XjuwBwECgqymXchpcm?= =?us-ascii?Q?TijLBLoM3wrY0zmREensWEreK98Y/XbKtXu8VM8E4jIVFLZcXUc/lgQY01zq?= =?us-ascii?Q?qY+shPFpRW0i410NxxpUmo0RYwMoRIlVprVbPp5aOCkJNYfgRsx3IxOIi+at?= =?us-ascii?Q?fv5IhUdUohbnuWVrUte8mWk7aSHkYovxNJAurcfro8S6Vq2uPCBf7PncSmMn?= =?us-ascii?Q?jBa2dV9M/b6NdzxTmUc1nGHaWqAdkLXzeWMZgRvKOM3Yvp6JIr2VuV4g48zI?= =?us-ascii?Q?j02e2HdLOSFs4Jyi8QrjPmglqG3CQWIvDDXoBa3UFr54zmBM+ZEpW1QMGQpQ?= =?us-ascii?Q?4jglMuPsauehbCHfMvFXzF5Ediow8GYPH5HZZdw5/nXh4bTBWsJYUOSxEsy7?= =?us-ascii?Q?VfHIu2XfOS+rIkrRdqr7ioSRL6s+Ym27MLp+jOjvSlA5kaLDBaJHQekf3NGG?= =?us-ascii?Q?2FVtGYzYXDy+1pfSfRVFrtOJ1tgyZLtnrRpBmDYWMR/vhyGTmy2AFMgB0uyt?= =?us-ascii?Q?YCVFneSe20qf8yNbzVnSMri4QYMun/9+m7PpXKOTMEt9bq/81jPXVSOMmw3F?= =?us-ascii?Q?pBknhG851bdn27t0Y+sXh4K/UwmHbpV51Mx377RROYY/0Xy7ILib0nhDkmZe?= =?us-ascii?Q?w6MLzQEt2HPy2ITAikc9Jc8sCNeBZyp8RihBx1GfPX5sI7AQBd+X5pbcvRos?= =?us-ascii?Q?+mWHfmOBw/MDq0gjFcsFo2B9suq4a2ESE8Y0mSK910MSm1+vrsob3fhskPTG?= =?us-ascii?Q?Y16k7yl0UWsDr1J7Bsf+OH6UUUlA5YhHayLK+exY/eTrUjk5emLwgYrEgG5l?= =?us-ascii?Q?Nh+tlhijXcNEqxSNp7LeKtzhEAQ+XZyh+3lDFQhTM5Hsqq3kIahHQHK8UUkU?= =?us-ascii?Q?RLqXPxn4AUIhA5852nCGgE0f6cvwUjZZLkJeaoLSd1ArBQucxvJcErhRSeqQ?= =?us-ascii?Q?YRQfzN1PRTVfdy/exU83va7Ze/zaGVdH7OY8ZVz1aYioK5x1m32I8mb5UKo5?= =?us-ascii?Q?VS0rE5IJKg7/+MCYMkx9qj3IRfJuOTUGa03gQ02KI9c7iEI3cKro7/bBirHq?= =?us-ascii?Q?istMEfyFZec2nVJOfutCQGFqzwoLOpwUNPNFumPK0p3FEZJ2ZUWnG6rfL/dx?= =?us-ascii?Q?seD/LEGeTeV2gRfXI4Sm6/W4OQ+V9E4/vkdJi62G0n7tZ9EfR5uIAkDx5HuB?= =?us-ascii?Q?9RupbCGi41nYYymkXhO7APad+WmR0hspGQ4WmsUDvsD9iYo4nIiyQfgl8638?= =?us-ascii?Q?+HVmV+OpnfTiOgzzFbz9IIPVnubplzFuf0vnXpMoyOHna49Sjv/dmujO8fIb?= =?us-ascii?Q?T7B9BhXSqqXJNgywk7tIK+fR8kywgyNMPVUFS6uZqHLzuioRugN2Ak9nI0So?= =?us-ascii?Q?hCs0Wvko6+WRJzlHiPmhqUJkgaynBplv3I6a4jXDe2OQtCoIvm+dwvzaI4Po?= =?us-ascii?Q?OWjqI7GoUDvM5BVp+RjW4t/GrfUwdxflCjHuVOXY?= X-OriginatorOrg: atomlin.com X-MS-Exchange-CrossTenant-Network-Message-Id: c41343d7-fbf4-4997-5fec-08dd30297a27 X-MS-Exchange-CrossTenant-AuthSource: CWLP123MB3523.GBRP123.PROD.OUTLOOK.COM X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 08 Jan 2025 21:14:45.8634 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: e6a32402-7d7b-4830-9a2b-76945bbbcb57 X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: eVBNytsi6mnXJZdca7XfJBbfDOUuhmiy7FkVtPkReJwAtPWtw4rv/Q4Trmh5urprjaWUW+4ljVBX5yJtKaBiXg== X-MS-Exchange-Transport-CrossTenantHeadersStamped: LO0P123MB6220 On Sun, 1 Dec 2024, Aaron Tomlin wrote: > Hi Oleg, Frederic, Peter, > > I have seen a case where maxcpus=1 and e.g. nohz_full=1,3-31, was used to > force the CPU affinity of certain unbound or non CPU-specific kernel > threads at boot-time. Albeit, since commit 9cc5b8656892a ("isolcpus: Affine > unbound kernel threads to housekeeping cpus") this is handled entirely via > nohz_full=. I thought it might be worth adding a warning. > > > Aaron Tomlin (1): > sched/isolation: Warn when maxcpus= is specified with nohz_full= or > isolcpus= > > kernel/sched/isolation.c | 2 ++ > 1 file changed, 2 insertions(+) > > -- > 2.47.1 Hi Oleg, Frederic, Peter, Any thoughts? -- Aaron Tomlin