[PATCH 02/13] sched_ext: Refactor do_enqueue_task() local and global DSQ paths

[Tejun Heo <tj@kernel.org>]

The local and global DSQ enqueue paths in do_enqueue_task() share the same
slice refill logic. Factor out the common code into a shared enqueue label.
This makes adding new enqueue cases easier. No functional changes.

Reviewed-by: Andrea Righi <arighi@nvidia.com>
Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
---
 kernel/sched/ext.c | 21 ++++++++++++---------
 1 file changed, 12 insertions(+), 9 deletions(-)

diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c
index 1a9b28dd0961..43083602c15e 100644
--- a/kernel/sched/ext.c
+++ b/kernel/sched/ext.c
@@ -1279,6 +1279,7 @@ static void do_enqueue_task(struct rq *rq, struct task_struct *p, u64 enq_flags,
 {
 	struct scx_sched *sch = scx_root;
 	struct task_struct **ddsp_taskp;
+	struct scx_dispatch_q *dsq;
 	unsigned long qseq;
 
 	WARN_ON_ONCE(!(p->scx.flags & SCX_TASK_QUEUED));
@@ -1346,8 +1347,17 @@ static void do_enqueue_task(struct rq *rq, struct task_struct *p, u64 enq_flags,
 direct:
 	direct_dispatch(sch, p, enq_flags);
 	return;
-
+local_norefill:
+	dispatch_enqueue(sch, &rq->scx.local_dsq, p, enq_flags);
+	return;
 local:
+	dsq = &rq->scx.local_dsq;
+	goto enqueue;
+global:
+	dsq = find_global_dsq(sch, p);
+	goto enqueue;
+
+enqueue:
 	/*
 	 * For task-ordering, slice refill must be treated as implying the end
 	 * of the current slice. Otherwise, the longer @p stays on the CPU, the
@@ -1355,14 +1365,7 @@ static void do_enqueue_task(struct rq *rq, struct task_struct *p, u64 enq_flags,
 	 */
 	touch_core_sched(rq, p);
 	refill_task_slice_dfl(sch, p);
-local_norefill:
-	dispatch_enqueue(sch, &rq->scx.local_dsq, p, enq_flags);
-	return;
-
-global:
-	touch_core_sched(rq, p);	/* see the comment in local: */
-	refill_task_slice_dfl(sch, p);
-	dispatch_enqueue(sch, find_global_dsq(sch, p), p, enq_flags);
+	dispatch_enqueue(sch, dsq, p, enq_flags);
 }
 
 static bool task_runnable(const struct task_struct *p)
-- 
2.51.2