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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?Tn/BmOsZEPfVdaXXelES3sX0lCrNcU9OsOSH1ZNOycV8VA1naa71vz8u8vlN?= =?us-ascii?Q?2uyWdUl1zu0pARW+P+hAgcR3jX6VhnOzH3pZ+sTBQ/l3FbtcK1+iYv5zjElb?= =?us-ascii?Q?L87pDt2QcaLrCDkTEPdczI69KRQW6I6JpFm4rmw4WLxKibcV8JATkdd9KwNP?= =?us-ascii?Q?3yMNPyFsdAQCF5ymzO43HMZwzS/xoYot/TJwyuWg6BvaH4uaOgAj16BdHiNd?= =?us-ascii?Q?Dj09tTdzGREm5RVdMeYALufp8zZyxsINZEZbQhGpKkjoZxYCyXo1VJ/MlXMF?= =?us-ascii?Q?kOeO5b30kZLXHppiroFbVF+xomjGWPWXgVWmWqGBMYf5DL69oVXDJlfbDA6B?= =?us-ascii?Q?LOInpIjpcdKPH999pwHK55ygC7x4n6tgTk4IqgSPPLiNnIBSm6A0CpZPwa20?= =?us-ascii?Q?f96njP9eBzjZ1ER2SIW9kzawOCeg9Wou1NfV8Q/9m5Ey2/D7jv4X/Fl6txc/?= =?us-ascii?Q?hrFhsa0XuwBYv45aurNNqmmsk499aiSfhi7xzAAGjAcz/s1clRj8ghTewQv5?= =?us-ascii?Q?TMiMQuyKFQ28rEOhHQYPDYkZIuKkySUnbiLaiiAuwTu8Xm0dTl4QpfJBdKZm?= =?us-ascii?Q?FO63VkDm3I40Y2uR9ebWEHrvyFr/GsxF1r3+dFASi6L4dkVEQmS3QjKKgp2+?= =?us-ascii?Q?nzbtWM7geaFKBRe1nLXM2YP81U041aWMK+O6kubpvc0g/c7s9utSOVvzl5bx?= =?us-ascii?Q?tUvGpK8HQsrq8LvYV3hC8AtAD2xuqttxP91rwU2Y8tDeV+lnlwui9vOoWasc?= =?us-ascii?Q?NRG4X0evhQ61paSG95Jxh+ZsStmVFirpGbg14FUjCOAIaTK4YzwM9eF6B1WY?= =?us-ascii?Q?+zETrKLOz2eNWZsG/M2vIU9wqf0EKsfgDQ+g7wlfVNVJtW5HC3wteaM+A7Wv?= =?us-ascii?Q?W8oc47B/30SCv/h6oYs11k2jyqKlRWpZal6VPWd8wfxnpus56Ptnb5cNL4qf?= =?us-ascii?Q?QJre0VON0C8ldCyrNqlWKW+vG/D31dCPhg4tZYd3LsjMJYg1+JtdD3HnoZmj?= =?us-ascii?Q?6AWKDJZD62n8kTDFjdRb6i/gzLCuhLFaSf8Fk3GkHF1TXUQJKR+GRsoJkYr/?= =?us-ascii?Q?HsKPWYIZy95ggxVVjL7pxVA1dj0OwlT5mooANayjXFN7HrpcpI8HRq6svvH5?= =?us-ascii?Q?NEMlvSmn6qw8vZ3XyltP7oLlMzfeMtjxQnx7RbbVIWnqedFgAOsrzRw7jyRm?= =?us-ascii?Q?3I46llKDOW6eBBFnDHw47tGdyTiR8XHI4cn8T0o+a0h3AkMI4f0meaQIVQOT?= =?us-ascii?Q?20tiaswfREuTjS7dvgFmoJOO9c4L+UxCqUNnJPFxHNjInO4QYCwEE9Yr31WW?= =?us-ascii?Q?1QGqgM4EO1D0xwyYy+1JPtI4nsLSno6GGCBg3ywRMh8FhuVoj0XBQAaEKdV8?= =?us-ascii?Q?Ip9LcjTIb/avX6SD35WPioh6dzfWy3oFQCY5DZXLHnPcpmPQ7QQ5iPxvMvUY?= =?us-ascii?Q?9CYP87XzjAEpSLbHbkc815YgDhzaoGsqc//HKxZjPrCqY9VnnZ3fhRSSIB6U?= =?us-ascii?Q?8DWPf6dbKl+4nEZ1hooo1dP1MaWgNfKlfXAZCe9Uju9qXoBdYAz1Me0ECdqB?= =?us-ascii?Q?FTyunhFm+bz6kMuf3BQA7OgiUAyGldxl4Y5TNviA?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 7a9a0157-ac04-4cc9-ae36-08ddfa71bcca X-MS-Exchange-CrossTenant-AuthSource: LV8PR12MB9620.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 23 Sep 2025 07:20:56.3401 (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: BswFIOvnjulpTen1AHQKmWwV9fb1xvXPx1IE5Rc7d3r6/o8LDMoY0bakh4yDJCc+SjRQvwZMlbgKLV6nVAokzg== X-MS-Exchange-Transport-CrossTenantHeadersStamped: CYYPR12MB8940 On Sun, Sep 21, 2025 at 03:32:41PM -1000, Tejun Heo wrote: > The comment for SCX_KF_DISPATCH was incomplete and didn't explain that > ops.dispatch() may temporarily release the rq lock, allowing ENQUEUE and > SELECT_CPU operations to be nested inside DISPATCH contexts. > > Update the comment to clarify this nesting behavior and provide better > context for when these operations can occur within dispatch. > > Signed-off-by: Tejun Heo Looks good. Acked-by: Andrea Righi > --- > include/linux/sched/ext.h | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/include/linux/sched/ext.h b/include/linux/sched/ext.h > index 7047101dbf58..d82b7a9b0658 100644 > --- a/include/linux/sched/ext.h > +++ b/include/linux/sched/ext.h > @@ -108,7 +108,11 @@ enum scx_kf_mask { > SCX_KF_UNLOCKED = 0, /* sleepable and not rq locked */ > /* ENQUEUE and DISPATCH may be nested inside CPU_RELEASE */ > SCX_KF_CPU_RELEASE = 1 << 0, /* ops.cpu_release() */ > - /* ops.dequeue (in REST) may be nested inside DISPATCH */ > + /* > + * ops.dispatch() may release rq lock temporarily and thus ENQUEUE and > + * SELECT_CPU may be nested inside. ops.dequeue (in REST) may also be > + * nested inside DISPATCH. > + */ > SCX_KF_DISPATCH = 1 << 1, /* ops.dispatch() */ > SCX_KF_ENQUEUE = 1 << 2, /* ops.enqueue() and ops.select_cpu() */ > SCX_KF_SELECT_CPU = 1 << 3, /* ops.select_cpu() */ > -- > 2.51.0 > Thanks, -Andrea