[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20230809204200.103286845@infradead.org>
Date: Wed, 09 Aug 2023 22:24:41 +0200
From: Peter Zijlstra <peterz@...radead.org>
To: mingo@...hat.com
Cc: peterz@...radead.org, juri.lelli@...hat.com,
vincent.guittot@...aro.org, dietmar.eggemann@....com,
rostedt@...dmis.org, bsegall@...gle.com, mgorman@...e.de,
bristot@...hat.com, vschneid@...hat.com,
linux-kernel@...r.kernel.org
Subject: [PATCH 1/8] sched: Simplify set_user_nice()
Use guards to reduce gotos and simplify control flow.
Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>
---
kernel/sched/core.c | 13 ++++++-------
kernel/sched/sched.h | 5 +++++
2 files changed, 11 insertions(+), 7 deletions(-)
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -7119,9 +7119,8 @@ static inline int rt_effective_prio(stru
void set_user_nice(struct task_struct *p, long nice)
{
bool queued, running;
- int old_prio;
- struct rq_flags rf;
struct rq *rq;
+ int old_prio;
if (task_nice(p) == nice || nice < MIN_NICE || nice > MAX_NICE)
return;
@@ -7129,7 +7128,9 @@ void set_user_nice(struct task_struct *p
* We have to be careful, if called from sys_setpriority(),
* the task might be in the middle of scheduling on another CPU.
*/
- rq = task_rq_lock(p, &rf);
+ CLASS(task_rq_lock, rq_guard)(p);
+ rq = rq_guard.rq;
+
update_rq_clock(rq);
/*
@@ -7140,8 +7141,9 @@ void set_user_nice(struct task_struct *p
*/
if (task_has_dl_policy(p) || task_has_rt_policy(p)) {
p->static_prio = NICE_TO_PRIO(nice);
- goto out_unlock;
+ return;
}
+
queued = task_on_rq_queued(p);
running = task_current(rq, p);
if (queued)
@@ -7164,9 +7166,6 @@ void set_user_nice(struct task_struct *p
* lowered its priority, then reschedule its CPU:
*/
p->sched_class->prio_changed(rq, p, old_prio);
-
-out_unlock:
- task_rq_unlock(rq, p, &rf);
}
EXPORT_SYMBOL(set_user_nice);
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -1630,6 +1630,11 @@ task_rq_unlock(struct rq *rq, struct tas
raw_spin_unlock_irqrestore(&p->pi_lock, rf->flags);
}
+DEFINE_LOCK_GUARD_1(task_rq_lock, struct task_struct,
+ _T->rq = task_rq_lock(_T->lock, &_T->rf),
+ task_rq_unlock(_T->rq, _T->lock, &_T->rf),
+ struct rq *rq; struct rq_flags rf)
+
static inline void
rq_lock_irqsave(struct rq *rq, struct rq_flags *rf)
__acquires(rq->lock)
Powered by blists - more mailing lists