From: Florian-Ewald Mueller <florian-ewald.mueller@xxxxxxxxx>
Check for sleeping thread before attempting its wake_up in
md_wakeup_thread() to avoid unnecessary spinlock contention.
With a 6.1 kernel, fio random read/write tests on many (>= 100)
virtual volumes, of 100 GiB each, on 3 md-raid5s on 8 SSDs each
(building a raid50), show by 3 to 4 % improved IOPS performance.
Signed-off-by: Florian-Ewald Mueller <florian-ewald.mueller@xxxxxxxxx>
Reviewed-by: Yu Kuai <yukuai3@xxxxxxxxxx>
Signed-off-by: Jack Wang <jinpu.wang@xxxxxxxxx>
---
drivers/md/md.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 7d7b982e369c..44253faa2633 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -8083,7 +8083,8 @@ void md_wakeup_thread(struct md_thread __rcu *thread)
if (t) {
pr_debug("md: waking up MD thread %s.\n", t->tsk->comm);
set_bit(THREAD_WAKEUP, &t->flags);
- wake_up(&t->wqueue);
+ if (wq_has_sleeper(&t->wqueue))
+ wake_up(&t->wqueue);
}
rcu_read_unlock();
}
--
2.34.1
