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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?HmanEshTguBwfGTNhoyStcCrnYPnB5ZXbPzY6YIwhS8FatLKaOWsJ3QoFUbx?= =?us-ascii?Q?55lF2QiK9BKRAcO5z/Pv6abbgp4y4mhaXciXCzLgjKYV4UbKrtzfaXYdcelg?= =?us-ascii?Q?0m3wCjV2qQiledMIVK+oLd9v30CqcJLE/huBbuerV8TfUf0MzRPWyZKTLli4?= =?us-ascii?Q?mMx+NxJb1bwrnmW5F0ZndTo96zjFYLbgp8RdkRk/dQVcWssLLFvX4W7+aG6w?= =?us-ascii?Q?k7lcbl5h8o7YISQukvFBbexCpSRSyP5hT43QbG5aqu/XFIZ4+C91D2IAWh7m?= =?us-ascii?Q?N56pqVj7zGRhVKFW4jUU63q/5MDDueL2l983dugC/LAN8lfNUcqjoj2sSYma?= =?us-ascii?Q?thdkG6RIP8zYDlKfYli7ppThMXweC6DHEKN+VaDCiW4OCPiQAt9Y0kV9t9sg?= =?us-ascii?Q?WRpi2IN5h2RMJRK7s1qg1gzFFW4o4pWZv29S1PzEV1ndeT2WiNRWUEduQYpx?= =?us-ascii?Q?48xBKzvfC5skJ+hbLmpuc5GQN3rK4WZFvrcQzaFgEJmbzNcBx3EuUuY2iTnm?= =?us-ascii?Q?SA0L4WT4OkLJNPnIMkNPDScJ3+G8RrBSrxwiMNR1+a5+u7tna1CvH9YlBoYH?= =?us-ascii?Q?H494fzAHRaWYbH1hS66u5YJHdlNXfZP4X92cSTt0SvEc/MxFTdbJO/qtlyP5?= =?us-ascii?Q?PpNNAV+bWzQLJ4SdRs+HmEEdTyLJmmDsySmRDLpZWo242XU2zBMeXpvxzymS?= =?us-ascii?Q?ljQLmqHp+AizgHGmWAVV7JSzX6VC1D2WnjqwI7Kx9rpVUI5Y86d+hAs7GPG+?= =?us-ascii?Q?ampxIyPNIAY958VdRjJjDhbsuAF3APM66yYMn6peAfnIDY1Q7KjeCmG2YvZL?= =?us-ascii?Q?D5/HmhJ/WjHmEwJALcH6mP7us+2ZOVxyEPTbAPxpDBXK7LZ+8SjF/KikA6Hw?= =?us-ascii?Q?GZ9e7CHBZzkvxjV6FtuoUQUkWaG1Ex4DRFgGxjJXB12ua2eGk4KYX3syJ006?= =?us-ascii?Q?Mnfu5RoBObek3Zp8Szy1u8XjbCB22VZt5C/34vNa0f6bfIu+WzCtjmjeXeSL?= =?us-ascii?Q?o1DBUOQH3Dh1//6nyTOUOpCIHG6pQrpdTi98Lm5tp6aw/A3LZTp707X6aGQs?= =?us-ascii?Q?waeO8IsiaekcLXIBSO1Y9NQmv6Nh92t5P1Y5kRIzzLa9EdZ7rpk6EFmcOxue?= =?us-ascii?Q?bh0VGiorroM5d7HAX7BmKm0c7xGpzRqehW4UN+rqkgKhmvUc3inMdidlvNMA?= =?us-ascii?Q?qetbsrZAFYYV0z5Hqv04TQ1tFOtUOAB8NTE3Q67CtqkY96OLRVnosU11lG3C?= =?us-ascii?Q?7MOcFGhOnjYoumHaKwZBbLGLOHgzhYGnz7rh/UYj89FemprHDtgmFqjtNTYW?= =?us-ascii?Q?a5M14nmj/eUPCdbCLLrjJlprwjvH71JI+zE3N4x7Oj6iwtoqMg1wbxQL8FRi?= =?us-ascii?Q?kj2uK2Lz08shk/ZUOnLyqPCSNdSe6b/nzObqHRl+jxAAqj9Pr+bBArPSHYNU?= =?us-ascii?Q?g9Vh9rcrjoBEm1Hl3+LMQxl9I4yLrhnUU/fPMDACw36lhO7GQkpsZObjTAKn?= =?us-ascii?Q?uWH6qxCWNO9LqtVLUr+JME/niPW3X+YX6NnLFLDkqXUPdoOlH97BG0jKMKDn?= =?us-ascii?Q?3QtSyMX02LLYvYHKUrgNN9hfjGYGNqnFH58tHkcHhyiYnINnhzdEX+x+xotu?= =?us-ascii?Q?7GZG+r1H/POs84b89tIgk2XZD7eGfssheTqbduqA9XxPxY8FS58G1z2RsUS1?= =?us-ascii?Q?Tr1Or2XBV7yCPH1Sy80x9ahsiFjBOrBucAwquWuQF/lYrD5cNnQea1GeHYg7?= =?us-ascii?Q?gZOl04suBA=3D=3D?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 71172661-a2ce-4028-812e-08df0b835351 X-MS-Exchange-CrossTenant-AuthSource: DM6PR12MB4827.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 05 Sep 2026 19:24:37.8152 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: +aG7N26Gl5RdeTYaZj9h/w+yj/G7qQI2FhdKxojiSU4w3ym9s4wYE7pBDi1Gf2rsG175wa6o77ccKIFL9vgARw== X-MS-Exchange-Transport-CrossTenantHeadersStamped: DS7PR12MB8346 On Sat, Sep 05, 2026 at 06:40:32AM -1000, Tejun Heo wrote: > Hello, > > > This is a pre-existing issue, but can lockless readers observe a transiently > > zeroed qa.self_cids.mask here and incorrectly fall through to the rescue block? > > Yes, but scx_qmap is an example scheduler and the result is a spurious rescue > insert, which isn't critical. The race is acceptable. BTW, while looking at this I noticed another potential different race in qmap_sub_ecaps_updated() busy/pending handoff. CPU0 CPU1 holds part_busy refresh_usable() using old avail update avail_cids part_try_start() fails sees part_pending == 0 part_end() returns sets part_pending = 1 IIUC, there's no owner left to consume part_pending immediately at this point, so usable_cids can remain stale until the next rr_advance() or redistribute() pass. It should self-correct, but a task may remain queued until another dispatch event. This is likely not a big problem either, just wanted to point it out as a separate one from the transient self_cids issue reported by Sashiko. Thanks, -Andrea