Merge tag 'sched_ext-for-7.3-rc6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext

Pull sched_ext fixes from Tejun Heo:

 - Taking a CPU offline could hang, or stall until the watchdog ejected
   the BPF scheduler, when tasks on the dying CPU were still held by the
   scheduler or sitting on a user dispatch queue. Re-enqueue them onto
   the local queue when the runqueue goes offline so that the CPU pushes
   them off like the other sched classes.

 - The sequence number guarding against stale dispatches was per
   runqueue, so a task re-enqueued on another CPU could get the same
   number and a dispatch meant for its earlier instance was applied to
   the new one. Use a per-task counter.

 - A task dispatched to another CPU's local queue got its ops.dequeue()
   only when picked to run and flagged as a core-sched pick. Call it at
   insertion like for same-CPU dispatches.

* tag 'sched_ext-for-7.3-rc6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext:
  sched_ext: Generate qseq from a per-task counter
  selftests/sched_ext: Add a test for ops.dequeue() on remote local DSQ moves
  sched_ext: Call ops.dequeue() when a task arrives on a remote local DSQ
  sched_ext: Fix CPU hotplug hang when a dying CPU's tasks sit in the BPF scheduler

1 files changed, 1 insertions, 0 deletions

diff --git a/include/linux/sched/ext.h b/include/linux/sched/ext.h
index 582d7cd4a983..36c04797436c 100644
--- a/include/linux/sched/ext.h
+++ b/include/linux/sched/ext.h
@@ -207,6 +207,7 @@ struct sched_ext_entity {
 	s32			holding_cpu;
 	s32			selected_cpu;
 	s32			runnable_cpu;	/* cpu @p is runnable on, -1 if not */
+	u32			ops_qseq;	/* protected by rq lock */
 	struct task_struct	*kf_tasks[2];	/* see SCX_CALL_OP_TASK() */
 
 	struct list_head	runnable_node;	/* rq->scx.runnable_list */