sched_ext: Factor out local_dsq_post_enq() from dispatch_enqueue()

Factor out local_dsq_post_enq() which performs post-enqueue handling for
local DSQs - triggering resched_curr() if SCX_ENQ_PREEMPT is specified or if
the current CPU is idle. No functional change.

This will be used by the next patch to fix move_local_task_to_local_dsq().

Cc: stable@vger.kernel.org # v6.12+
Reviewed-by: Andrea Righi <arighi@nvidia.com>
Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c
index c4465ccefea48af08b8975b5e5d4fcb997877428..c78efa99406fffc8649c33d00b3dd0b559e7031a 100644 (file)
--- a/kernel/sched/ext.c
+++ b/kernel/sched/ext.c
@@ -982,6 +982,22 @@ static void refill_task_slice_dfl(struct scx_sched *sch, struct task_struct *p)
        __scx_add_event(sch, SCX_EV_REFILL_SLICE_DFL, 1);
 }
 
+static void local_dsq_post_enq(struct scx_dispatch_q *dsq, struct task_struct *p,
+                              u64 enq_flags)
+{
+       struct rq *rq = container_of(dsq, struct rq, scx.local_dsq);
+       bool preempt = false;
+
+       if ((enq_flags & SCX_ENQ_PREEMPT) && p != rq->curr &&
+           rq->curr->sched_class == &ext_sched_class) {
+               rq->curr->scx.slice = 0;
+               preempt = true;
+       }
+
+       if (preempt || sched_class_above(&ext_sched_class, rq->curr->sched_class))
+               resched_curr(rq);
+}
+
 static void dispatch_enqueue(struct scx_sched *sch, struct scx_dispatch_q *dsq,
                             struct task_struct *p, u64 enq_flags)
 {
@@ -1093,22 +1109,10 @@ static void dispatch_enqueue(struct scx_sched *sch, struct scx_dispatch_q *dsq,
        if (enq_flags & SCX_ENQ_CLEAR_OPSS)
                atomic_long_set_release(&p->scx.ops_state, SCX_OPSS_NONE);
 
-       if (is_local) {
-               struct rq *rq = container_of(dsq, struct rq, scx.local_dsq);
-               bool preempt = false;
-
-               if ((enq_flags & SCX_ENQ_PREEMPT) && p != rq->curr &&
-                   rq->curr->sched_class == &ext_sched_class) {
-                       rq->curr->scx.slice = 0;
-                       preempt = true;
-               }
-
-               if (preempt || sched_class_above(&ext_sched_class,
-                                                rq->curr->sched_class))
-                       resched_curr(rq);
-       } else {
+       if (is_local)
+               local_dsq_post_enq(dsq, p, enq_flags);
+       else
                raw_spin_unlock(&dsq->lock);
-       }
 }
 
 static void task_unlink_from_dsq(struct task_struct *p,