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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?aFlYS7fcn7WVTQmWmyWQJUxzNBf/50HnBf2iQT/570nWNVacGaCIJ8E6UWjq?= =?us-ascii?Q?5vv+KpvVnSrsYaYIyvIvdgnPBoAqfGVR9PSKOSWzW0w0E2+vTu4WlVp7Fg05?= =?us-ascii?Q?xkuPiP/KxaBtE5h9rKvr4SerziS8N96nrbFY4fSyi4wAIQh4mKKG1KAUy2qk?= =?us-ascii?Q?Gk2IaeSgnBwDZ10D3OpdzwjzTVpeAZzhpatHLMV1RnawCAaFZCX6iFRA9HvT?= =?us-ascii?Q?7spOyO30Y+yYUJazi/QLC/WsWq4cK43LchAxzHE/6aWutn97UGn0qhkhJ2og?= =?us-ascii?Q?pTD6lgk2tDFu/f2setV7jPDlHVn2JMOOJaAk1wfjsWkLr6tDiKqxR5k3fllL?= =?us-ascii?Q?1rT2yTw9m/GT6e27UGmIIlJbJzLEAm9l8DCrmFqNdbnHp7dEefeUKT/25ZPa?= =?us-ascii?Q?NMuxMnf0WGiuLSrpOdLg9iTX0KDfVLrBY1TJUhCuLtYbayDnWNBYo4GI5NYr?= =?us-ascii?Q?fN1jCqAErDCCPH4ij3zhLkqHqS1Kd8uZy0EW/IZEpx5H7/biKsYvhEvpXyXB?= =?us-ascii?Q?D007/tuRjoucLU0rR1ATBzDQwvPK+hCaFu8q58F3uLfw2L5xqeIPKpCAQo9U?= =?us-ascii?Q?QgzRgN5f2frVdhV6WiHDhVjbdezNWU6rfZU1JrfvG2keb2VA2l5J0e9fi9Qm?= =?us-ascii?Q?Ozo00jxDoHtddYKxv7PMjmQp2O4jJ+Ikb3n1xUTHGJSm+f/F+Lu57lR3JGEJ?= =?us-ascii?Q?KPx4SbK/2KvlXwoQFWZl5gy3uq6UV+LZTwFIa7RWFcgHUYnPkJ6S6kfJjF9t?= =?us-ascii?Q?/PeFKTZpISrmq272b3GYR7gzSOm8M8fedSIUXlgbTQuCq14HFEsxZPQ5MphR?= =?us-ascii?Q?UHpxorbio3+1YsVSdCR0vKTN4kVSm6z0dILUb6AIxguQs20tx7coSZFE77+9?= =?us-ascii?Q?tBaE/6M1vfFtuhHzpTio7NG7TwmgRQiHDfBAXU9m/ZF27K54K22HQgZK5RYH?= =?us-ascii?Q?wvEBIisdAxxvEXWB7Q4B0JmxS4jMYkZytvLXCDNOcT+/bMia7vGLusg4KYYx?= =?us-ascii?Q?h+wkrwqGQt8xKBeKI2dNc6VvOc3qwTuHa66A1X8USa9ZEpv0SBZUyoaVg9Eq?= =?us-ascii?Q?VKvhL9HwQb2hFhRk9NRx5RffjQaPpaniPL4A/u+6j8NiZeOWnhSYCSXdszIY?= =?us-ascii?Q?Yq1ABlHvvOST/C5MeqmhlpGbB6Pn+7T6G/kUjiKh3jUuHePQayJyHKPN9I2t?= =?us-ascii?Q?+2fCuB1n7dcs65PA57OagihtBhJ+fdFNTbjF0TR2Xy/FiuoC2/7FQyvI71Kq?= =?us-ascii?Q?9OnYvgxV5o4QorLqp3/yTl6dx+BLilxiMTJ5oSWT5S3QaEbKZJSwW5vSqD/F?= =?us-ascii?Q?v97tmdz3KNmczKvUqjgN4aXpqrg8PawQpjF28jvI+5oKGjuN8I1XcgJv2xE+?= =?us-ascii?Q?LIrqlxwGu2oPT5V/6W1ZjQbciGBVHFYbOYMvSL15WufEIaaipxY57Okpb/K3?= =?us-ascii?Q?31Xda05L1w8QAuj0iirBKG0s3fygKHNvmGOT7sRTRcI0xvFgSN2loaw6Iuu9?= =?us-ascii?Q?FqV8xr3QWxSdtGxbBG9pRk0+MA6cIhsQ77oi/3GF2kkD3xuAiRlAR3QjHov0?= =?us-ascii?Q?1tvA+A7tIWcTxCpGhImJzmIRzFacuPqZiQDEFD9+6ZpCazJBUM5Fw6Hn1Lpp?= =?us-ascii?Q?UIoDRWRZhQtj5q+q7ZK/Yq2w+pEswM+UYrmF6M6MUFObFYw2O70ppaX3weyc?= =?us-ascii?Q?7aPn99VeBSOMLe1knuW7rs8mM3JX3KeFH/EK8KK28ase1hHgiQvlQwQl9WuE?= =?us-ascii?Q?Keh66Kif3w=3D=3D?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: b9014f20-daf1-41d8-e76e-08de9eeb5f11 X-MS-Exchange-CrossTenant-AuthSource: LV8PR12MB9620.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 20 Apr 2026 14:44:48.4402 (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: byjOH3lETfKAkg80Q8ahIia9k2/u5eMoVpHINY9zwtfkN87bpALGQ85s6t598+eheaFYCyQcqU8ANFq71s8sWg== X-MS-Exchange-Transport-CrossTenantHeadersStamped: IA0PR12MB7554 Hi Kuba, On Mon, Apr 20, 2026 at 02:39:39PM +0000, Kuba Piecuch wrote: > Commit 84b1a0ea0b7c > ("sched_ext: Implement scx_bpf_dsq_reenq() for user DSQs") > introduced the possibility of ops.enqueue() being called multiple times > in a row for the same task without intervening calls to ops.dequeue(). > AFAIK this was not possible before that commit. > Document this behavior as it may be surprising to some. > > Signed-off-by: Kuba Piecuch Looks good to me and I think it's good to document this special case. Acked-by: Andrea Righi Thanks, -Andrea > --- > Documentation/scheduler/sched-ext.rst | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/Documentation/scheduler/sched-ext.rst b/Documentation/scheduler/sched-ext.rst > index 03d595d178ea..fba09aa1cd4e 100644 > --- a/Documentation/scheduler/sched-ext.rst > +++ b/Documentation/scheduler/sched-ext.rst > @@ -339,6 +339,11 @@ The following briefly shows how a waking task is scheduled and executed. > leaves (e.g., when ``ops.dispatch()`` moves it to a terminal DSQ, or > on property change / sleep). > > + Note that ``ops.enqueue()`` can be called multiple times in a row without > + an intervening call to ``ops.dequeue()``. This can happen, for example, > + when a task on a user-created DSQ is re-enqueued using > + ``scx_bpf_dsq_reenq()``. The task stays in BPF custody the entire time. > + > When a task leaves BPF scheduler custody, ``ops.dequeue()`` is invoked. > The dequeue can happen for different reasons, distinguished by flags: > > -- > 2.54.0.rc1.555.g9c883467ad-goog >