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client-ip=165.204.84.17; helo=satlexmb07.amd.com; pr=C Received: from satlexmb07.amd.com (165.204.84.17) by SN1PEPF00026369.mail.protection.outlook.com (10.167.241.134) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9745.21 via Frontend Transport; Tue, 31 Mar 2026 17:02:58 +0000 Received: from Satlexmb09.amd.com (10.181.42.218) by satlexmb07.amd.com (10.181.42.216) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.17; Tue, 31 Mar 2026 12:02:50 -0500 Received: from satlexmb07.amd.com (10.181.42.216) by satlexmb09.amd.com (10.181.42.218) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.17; Tue, 31 Mar 2026 10:02:40 -0700 Received: from [172.31.184.125] (10.180.168.240) by satlexmb07.amd.com (10.181.42.216) with Microsoft SMTP Server id 15.2.2562.17 via Frontend Transport; Tue, 31 Mar 2026 12:02:36 -0500 Message-ID: <75446011-1612-4c6e-8141-7fc83d1df582@amd.com> Date: Tue, 31 Mar 2026 22:32:35 +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 v2 1/7] sched/fair: Fix zero_vruntime tracking To: Peter Zijlstra CC: John Stultz , , , , , , , , , , , , , , Suleiman Souhlal References: <73dab51a-650f-4c82-9e73-13236b2a26c2@amd.com> <20260330144005.GP3738786@noisy.programming.kicks-ass.net> <20260330191108.GU2872@noisy.programming.kicks-ass.net> <20260331070822.GC3739027@noisy.programming.kicks-ass.net> <20260331071402.GN3739106@noisy.programming.kicks-ass.net> <19667aac-99c4-40cf-bc0a-b1e6b9d32ede@amd.com> <20260331092909.GQ3738010@noisy.programming.kicks-ass.net> <20260331122035.GO3739106@noisy.programming.kicks-ass.net> <20260331161443.GA134305@noisy.programming.kicks-ass.net> Content-Language: en-US From: K Prateek Nayak In-Reply-To: <20260331161443.GA134305@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: wwVxtaFKac/r9EMpeV1pxegjdsOG/wO9hJaa5BP7f/fzggat+gUIfWqrj20mYIr1RybGf2mA07kelIbQOeLoDhJrMpypdNN3ryhyxQaQsw8LWPEI2wEGbztoGZ1nzDaBaF5q0koJ7UVXq5Xh+yArxFjiQWd5jBwN/3+9sxVHeg4kgcKyJfI8SRoPhOlqZ7/0gYVe4RiXV0lIB+oPSMupoTCR/SbNaudMMIuEwcEfhOcZnXCw5MTPujSZdofjWQYLImrIWEljEhNM9HD0UN4PqoXpF8EgpdiLkSvKUQoetIlMJWzI+VGFD9JNC4DSF3mUm8ktjmxdvQ3N7flNhGrdjRXylym68DKBtF+UagmddxRv6SkErA00TqPIkAlHQ57609pxycmLLFO9v8ebHe6kFeCpYd5bqrytkr9JxWGyJVE2ur+rSXfhaJXGwBhCDRNP X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 31 Mar 2026 17:02:58.2767 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: cdad35ec-9316-4d37-8b79-08de8f475c0f 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=[satlexmb07.amd.com] X-MS-Exchange-CrossTenant-AuthSource: SN1PEPF00026369.namprd02.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: DS7PR12MB6335 On 3/31/2026 9:44 PM, Peter Zijlstra wrote: > @@ -925,6 +926,7 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq) > if (last) > right_vruntime = last->vruntime; > zero_vruntime = cfs_rq->zero_vruntime; > + avruntime = avg_vruntime(cfs_rq); > raw_spin_rq_unlock_irqrestore(rq, flags); Ah! Didn't notice we dropped the lock as soon as we are done reading the necessary values. Makes sense why reading the debugfs under heavy load crashed. Ran 100 loops of reading the debug file while running stress-ng + sched-messaging and I haven't see any crashes yet so feel free to include: Tested-by: K Prateek Nayak > > SEQ_printf(m, " .%-30s: %Ld.%06ld\n", "left_deadline", -- Thanks and Regards, Prateek