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client-ip=165.204.84.17; helo=satlexmb08.amd.com; pr=C Received: from satlexmb08.amd.com (165.204.84.17) by BN1PEPF00005FFC.mail.protection.outlook.com (10.167.243.228) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9611.8 via Frontend Transport; Tue, 10 Feb 2026 20:04:37 +0000 Received: from satlexmb10.amd.com (10.181.42.219) 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, 10 Feb 2026 14:04:37 -0600 Received: from satlexmb08.amd.com (10.181.42.217) by satlexmb10.amd.com (10.181.42.219) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.17; Tue, 10 Feb 2026 14:04:36 -0600 Received: from [172.31.184.125] (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, 10 Feb 2026 14:04:32 -0600 Message-ID: <45678bce-3193-4d10-9655-d8014b1d0fa8@amd.com> Date: Wed, 11 Feb 2026 01:34:31 +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: [PATCH 0/4] sched: Various reweight_entity() fixes To: Peter Zijlstra CC: Doug Smythies , , , , , , , , , , , , References: <20260130093439.803225718@infradead.org> <4c48fe59-8ff3-41fb-83cb-869409f6fbc6@amd.com> <20260203111134.GL1282955@noisy.programming.kicks-ass.net> <38ef3462-4c4e-4f40-8d63-84dd71cbd043@amd.com> <20260209154718.GW1282955@noisy.programming.kicks-ass.net> <001901dc9aa3$cbad47f0$6307d7d0$@telus.net> <04ffa7ce-85ba-431b-91ab-f725f31b03ed@amd.com> <20260210183515.GI3016024@noisy.programming.kicks-ass.net> Content-Language: en-US From: K Prateek Nayak In-Reply-To: <20260210183515.GI3016024@noisy.programming.kicks-ass.net> Content-Type: text/plain; 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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: amosyoDuaKZiEk+rcw7feiIAyybfkXBnwUZQ17RWiRsS4tOxPjx8IJGuKy/ooh0DrOUX5M4JVThtSFdgkB/SGUNlMqKfui7AncTMD6NMZQNcESMEdp0dy0ctE8scyHF9f/fccEjzr6WJZS0qIJ+ah0MOW8gNesDZyQ2M4o5JVXooltYHtXFaxM0LUHqjEeABYPrAfqmaq35Z74WTEpsBiNPYhBX2f/4hGhtrjK0uB3WLtcktVn7uvsT3VsT8NxVgkXhwJV4GsLl2HfMG9XXNFWKXUViVlJdeaZaNi2fVWMAtvA/9d+qxa3k16hGEXgSeZqtxt2lotfQLbPdPEEkgriklDSP2vntXzqzsTp9FG818Dh8V8c8rX6JFG/mo2cMhnrXK8i52C8525a1TZSo/v4yJnQilF5u0ezU/SMs21xfPRhdm28fJsrVjEtwdxilV X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 10 Feb 2026 20:04:37.3293 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 49d47c90-7d10-4b1c-b155-08de68df9e30 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: BN1PEPF00005FFC.namprd05.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: BY5PR12MB4068 On 2/11/2026 12:05 AM, Peter Zijlstra wrote: > On Tue, Feb 10, 2026 at 11:39:14PM +0530, K Prateek Nayak wrote: > > >> Since you mentioned there is some bound to the number of copies when >> the hang is observed, can you please share your system details and >> the number of CPUs it has? > > He had that information in another email, 6 cores/12 threads. Ah! My bad. should have dug deeper. > > For me, I got to 21160 spread over 12 threads when it went boom. That > translates to aroun 1763 per CPU. Which is a fairly silly number of > active tasks, but it *should* work. > > It's a bit tedious to reproduce, but I'll prod at it some too. My machine hasn't cracked yet with 30k instances. I'll too will prod more tomorrow. -- Thanks and Regards, Prateek