[v3,12/57] sched: Simplify try_steal_cookie()

Commit Message

Peter Zijlstra June 12, 2023, 9:07 a.m. UTC

Use guards to reduce gotos and simplify control flow.

Signed-off-by: Peter Zijlstra (Intel) <[e-mail]>
---
 kernel/sched/core.c |   21 +++++++++------------
 1 file changed, 9 insertions(+), 12 deletions(-)

Patch

--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -6229,19 +6229,19 @@  static bool try_steal_cookie(int this, i
 	unsigned long cookie;
 	bool success = false;
 
-	local_irq_disable();
-	double_rq_lock(dst, src);
+	guard(irq)();
+	guard(double_rq_lock)(dst, src);
 
 	cookie = dst->core->core_cookie;
 	if (!cookie)
-		goto unlock;
+		return false;
 
 	if (dst->curr != dst->idle)
-		goto unlock;
+		return false;
 
 	p = sched_core_find(src, cookie);
 	if (!p)
-		goto unlock;
+		return false;
 
 	do {
 		if (p == src->core_pick || p == src->curr)
@@ -6253,9 +6253,10 @@  static bool try_steal_cookie(int this, i
 		if (p->core_occupation > dst->idle->core_occupation)
 			goto next;
 		/*
-		 * sched_core_find() and sched_core_next() will ensure that task @p
-		 * is not throttled now, we also need to check whether the runqueue
-		 * of the destination CPU is being throttled.
+		 * sched_core_find() and sched_core_next() will ensure
+		 * that task @p is not throttled now, we also need to
+		 * check whether the runqueue of the destination CPU is
+		 * being throttled.
 		 */
 		if (sched_task_is_throttled(p, this))
 			goto next;
@@ -6273,10 +6274,6 @@  static bool try_steal_cookie(int this, i
 		p = sched_core_next(p, cookie);
 	} while (p);
 
-unlock:
-	double_rq_unlock(dst, src);
-	local_irq_enable();
-
 	return success;
 }