Commit b4e1fa1e authored by Peter Zijlstra's avatar Peter Zijlstra
Browse files

sched: Simplify try_steal_cookie() 



Use guards to reduce gotos and simplify control flow.

Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: default avatarValentin Schneider <vschneid@redhat.com>
Link: https://lore.kernel.org/r/20230801211812.304154828@infradead.org
parent 6dafc713

kernel/sched/core.c

+9 −12
Original line number Diff line number Diff line
@@ -6298,19 +6298,19 @@ static bool try_steal_cookie(int this, int that) 
	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)
@@ -6322,9 +6322,10 @@ static bool try_steal_cookie(int this, int that) 
		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;
@@ -6342,10 +6343,6 @@ static bool try_steal_cookie(int this, int that) 
		p = sched_core_next(p, cookie);

	} while (p);



unlock:

	double_rq_unlock(dst, src);

	local_irq_enable();



	return success;

}