[PATCH v3 19/57] sched: Simplify sched_move_task()

From: Peter Zijlstra
Date: Mon Jun 12 2023 - 05:58:13 EST


Use guards to reduce gotos and simplify control flow.

Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
---
kernel/sched/core.c | 10 ++++------
1 file changed, 4 insertions(+), 6 deletions(-)

--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -10361,17 +10361,18 @@ void sched_move_task(struct task_struct
int queued, running, queue_flags =
DEQUEUE_SAVE | DEQUEUE_MOVE | DEQUEUE_NOCLOCK;
struct task_group *group;
- struct rq_flags rf;
struct rq *rq;

- rq = task_rq_lock(tsk, &rf);
+ CLASS(task_rq_lock, rq_guard)(tsk);
+ rq = rq_guard.rq;
+
/*
* Esp. with SCHED_AUTOGROUP enabled it is possible to get superfluous
* group changes.
*/
group = sched_get_task_group(tsk);
if (group == tsk->sched_task_group)
- goto unlock;
+ return;

update_rq_clock(rq);

@@ -10396,9 +10397,6 @@ void sched_move_task(struct task_struct
*/
resched_curr(rq);
}
-
-unlock:
- task_rq_unlock(rq, tsk, &rf);
}

static inline struct task_group *css_tg(struct cgroup_subsys_state *css)