The following commit has been merged into the sched/core branch of tip:
Commit-ID: 4eb054f92b066ec0a0cba6896ee8eff4c91dfc9e
Gitweb: https://git.kernel.org/tip/4eb054f92b066ec0a0cba6896ee8eff4c91dfc9e
Author: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
AuthorDate: Tue, 01 Aug 2023 22:41:25 +02:00
Committer: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
CommitterDate: Mon, 14 Aug 2023 17:01:25 +02:00
sched: Simplify wake_up_if_idle()
Use guards to reduce gotos and simplify control flow.
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Reviewed-by: Valentin Schneider <vschneid@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20230801211812.032678917@xxxxxxxxxxxxx
---
kernel/sched/core.c | 20 ++++++--------------
kernel/sched/sched.h | 15 +++++++++++++++
2 files changed, 21 insertions(+), 14 deletions(-)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 66478a6..65ebf43 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -3939,21 +3939,13 @@ static void __ttwu_queue_wakelist(struct task_struct *p, int cpu, int wake_flags
void wake_up_if_idle(int cpu)
{
struct rq *rq = cpu_rq(cpu);
- struct rq_flags rf;
-
- rcu_read_lock();
- if (!is_idle_task(rcu_dereference(rq->curr)))
- goto out;
-
- rq_lock_irqsave(rq, &rf);
- if (is_idle_task(rq->curr))
- resched_curr(rq);
- /* Else CPU is not idle, do nothing here: */
- rq_unlock_irqrestore(rq, &rf);
-
-out:
- rcu_read_unlock();
+ guard(rcu)();
+ if (is_idle_task(rcu_dereference(rq->curr))) {
+ guard(rq_lock_irqsave)(rq);
+ if (is_idle_task(rq->curr))
+ resched_curr(rq);
+ }
}
bool cpus_share_cache(int this_cpu, int that_cpu)
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index c299a58..3a01b7a 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -1705,6 +1705,21 @@ rq_unlock(struct rq *rq, struct rq_flags *rf)
raw_spin_rq_unlock(rq);
}
+DEFINE_LOCK_GUARD_1(rq_lock, struct rq,
+ rq_lock(_T->lock, &_T->rf),
+ rq_unlock(_T->lock, &_T->rf),
+ struct rq_flags rf)
+
+DEFINE_LOCK_GUARD_1(rq_lock_irq, struct rq,
+ rq_lock_irq(_T->lock, &_T->rf),
+ rq_unlock_irq(_T->lock, &_T->rf),
+ struct rq_flags rf)
+
+DEFINE_LOCK_GUARD_1(rq_lock_irqsave, struct rq,
+ rq_lock_irqsave(_T->lock, &_T->rf),
+ rq_unlock_irqrestore(_T->lock, &_T->rf),
+ struct rq_flags rf)
+
static inline struct rq *
this_rq_lock_irq(struct rq_flags *rf)
__acquires(rq->lock)
|