selftests/sched_ext: Add a test for ops.dequeue() on remote local DSQ moves

2026-09-30T17:49:52Z

Add a dequeue_remote test that makes moves of tasks in the BPF scheduler's custody to another CPU's local DSQ the common case, both via SCX_DSQ_LOCAL_ON dispatch and via scx_bpf_dsq_move_to_local(). The BPF scheduler tracks each task's custody state and triggers scx_bpf_error() if a custody period doesn't end with exactly one ops.dequeue() before the task runs, or if it ends with an SCX_DEQ_CORE_SCHED_EXEC dequeue of a task without a core cookie. Without the previous patch, the test fails with: sched_ext: dequeue_remote: dequeue_remote.bpf.c:141: 15 (rcu_preempt): late ops.dequeue() with SCX_DEQ_CORE_SCHED_EXEC (enq_cpu=3 cpu=2 seq=1) ... ops_dequeue+0x114/0x170 set_next_task_scx+0x104/0x1e0 __pick_next_task+0xc7/0x180 __schedule+0x154/0x1870 Reviewed-by: Andrea Righi Assisted-by: Claude:claude-opus-5.5 Signed-off-by: Kuba Piecuch Signed-off-by: Tejun Heo

laptop-kernel/tools/testing/selftests/sched_ext/dequeue_remote.bpf.c, branch master

selftests/sched_ext: Add a test for ops.dequeue() on remote local DSQ moves