[stable-4.14 07/11] sched: introduce this_rq_lock_irq()

[Jack Wang <jinpuwang@gmail.com>]

From: Johannes Weiner <hannes@cmpxchg.org>

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.

Link: http://lkml.kernel.org/r/20180828172258.3185-8-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Suren Baghdasaryan <surenb@google.com>
Tested-by: Daniel Drake <drake@endlessm.com>
Cc: Christopher Lameter <cl@linux.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Johannes Weiner <jweiner@fb.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Enderborg <peter.enderborg@sony.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vinayak Menon <vinmenon@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit d7edeb7f6a545695f064ce3787689f85e1e8b6dd)
Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com>
---
 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 0552ddbb25e2..a0b7e66c7281 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -4817,9 +4817,7 @@ SYSCALL_DEFINE0(sched_yield)
 	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 5ea86c072c07..e73d5d68602d 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -1041,6 +1041,18 @@ 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,
-- 
2.17.1