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McKenney" , Metin Kaya , Xuewen Yan , Thomas Gleixner , "Daniel Lezcano" , Suleiman Souhlal , kuyo chang , hupu , , Mike Galbraith References: <20260526111609.433880331@infradead.org> <20260526113322.596522894@infradead.org> <20260601105425.GQ3493090@noisy.programming.kicks-ass.net> Content-Language: en-US From: K Prateek Nayak In-Reply-To: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: BN1PEPF00004687:EE_|CY5PR12MB6645:EE_ X-MS-Office365-Filtering-Correlation-Id: ff44d3bf-317d-4429-d5b1-08dec066e9ff X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|82310400026|1800799024|30052699003|7416014|376014|36860700016|13003099007|4143699003|22082099003|18002099003|56012099006|11063799006; X-Microsoft-Antispam-Message-Info: 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 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)(82310400026)(1800799024)(30052699003)(7416014)(376014)(36860700016)(13003099007)(4143699003)(22082099003)(18002099003)(56012099006)(11063799006);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: LRSN3ZUGiqVTBltfbcq8lvbjFvrP/k1S8x6wXnQb9r50CUhuhzD3R4ryT3+vnF1w0U0WYtpHkKPGJpQowhrDvs3mgxrXUYxshetJYYDy24DUzzuR/oN/GOASz0yYMOU/Hkx4b7NZ14x8TV8ecDWJ3+YUR28Qe0hr1/lBpi073q8uZCrG71naD7pVuZJwEvN8ANLyGEoAKc8BcBslRj6psacWl56/DxP/vlHspj34USv3xWkuSZ0Azw3aYxR0JyGcTivIeij0PWhDOnQhcQUTDzoOWYV0hyGyX/cIl+Xg8IGmtc4kygNXlcQZ1PD2HYtFlgtTXmbfcUVAPEhhly1AmOpN4dqQN7piV/uR5HFOeXjL/p1vlPPIDqnEqg3zDcEU2f/vBjIn19lDptU0xlLHbvqIsxQ3SP04CDICvwwz3bjTinnxLRpe2Qd68K8cs0H6 X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 02 Jun 2026 05:22:17.7833 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: ff44d3bf-317d-4429-d5b1-08dec066e9ff 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: BN1PEPF00004687.namprd05.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: CY5PR12MB6645 Hello John, On 6/2/2026 2:02 AM, John Stultz wrote: > On Mon, Jun 1, 2026 at 3:54 AM Peter Zijlstra wrote: >> On Tue, May 26, 2026 at 01:16:14PM +0200, Peter Zijlstra wrote: >>> From: K Prateek Nayak >>> >>> Now that the proxy path uses ->is_blocked, use the '->is_blocked && >>> !->blocked_on' state instead of PROXY_WAKING. Notably, this is where a >>> blocked_on relation is broken but the donor task might still need a return >>> migration. >>> >>> (Not-yet-)Signed-off-by: K Prateek Nayak >>> Signed-off-by: Peter Zijlstra (Intel) >> >> Prateek, can I make that a normal SoB from you? I'm thinking I should >> merge sched/proxy into sched/core so we can get on with other stuff. > > Just as a heads up, so in stress testing[1] over the weekend with your > sched/proxy series, I hit the below null ptr traversal that seems to > be another pick_eevdf() returning null issue. > > I'm not sure if this is proxy related or not yet, so I'll be working > to reproduce (took ~31 hours to trip this one) and narrow it down. > But I'm wondering, given this pick_eevdf() returning null symptom has > been a regular issue for various bugs over time, do we need some > better debug checks to try to better these narrow down? I think PARANOID_AVG sched feat allows for some indication if things have gone sideways without crashing but there isn't an easy way to get the cfs_rq state which led to the crash without a crash kernel. > > This was using your tree at 4d92e41a046d, plus one workaround for > binutils on my system: > https://lore.kernel.org/lkml/7b45d196-063e-4e76-b08b-ec2bcc111328@linux.ibm.com/ Could you also try merging tip:sched/urgent into this branch and rerunning. commit b6eee96843e8 ("sched/fair: Fix overflow in vruntime_eligible()") in v7.1-rc3 moved to using 128-bit data type for the eligibility check and it can catch cases where an overflow in the multiplication will cause all entities to appear ineligible. -- Thanks and Regards, Prateek