Commit 3821bbad authored by Florian-Ewald Mueller's avatar Florian-Ewald Mueller Committed by Song Liu
Browse files

md: add check for sleepers in md_wakeup_thread() 



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: default avatarFlorian-Ewald Mueller <florian-ewald.mueller@ionos.com>
Reviewed-by: default avatarYu Kuai <yukuai3@huawei.com>
Signed-off-by: default avatarJack Wang <jinpu.wang@ionos.com>
Link: https://lore.kernel.org/r/20240327114022.74634-1-jinpu.wang@ionos.com


Signed-off-by: default avatarSong Liu <song@kernel.org>
parent 151f66bb

drivers/md/md.c

+2 −1
Original line number Diff line number Diff line
@@ -8087,6 +8087,7 @@ 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);

		if (wq_has_sleeper(&t->wqueue))

			wake_up(&t->wqueue);

	}

	rcu_read_unlock();