[PATCH 7/9] sched: introduce this_rq_lock_irq()

Johannes Weiner
2018-08-28T17:22:56Z

do_sched_yield() disables IRQs, looks up this_rq() and locks it. The
next patch is adding another site with the same pattern, so provide a
convenience function for it.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
---
kernel/sched/core.c | 4 +---
kernel/sched/sched.h | 12 ++++++++++++
2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index fe365c9a08e9..61059e671fc6 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -4960,9 +4960,7 @@ static void do_sched_yield(void)
struct rq_flags rf;
struct rq *rq;

- local_irq_disable();
- rq = this_rq();
- rq_lock(rq, &rf);
+ rq = this_rq_lock_irq(&rf);

schedstat_inc(rq->yld_count);
current->sched_class->yield_task(rq);
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index eb9b1326906c..83db5de1464c 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -1126,6 +1126,18 @@ rq_unlock(struct rq *rq, struct rq_flags *rf)
raw_spin_unlock(&rq->lock);
}

+static inline struct rq *
+this_rq_lock_irq(struct rq_flags *rf)
+ __acquires(rq->lock)
+{
+ struct rq *rq;
+
+ local_irq_disable();
+ rq = this_rq();
+ rq_lock(rq, rf);
+ return rq;
+}
+
#ifdef CONFIG_NUMA
enum numa_topology_type {
NUMA_DIRECT,
--
2.18.0