diff mbox series

[RESEND,v6,6/8] blk-throttle: calling throtl_dequeue/enqueue_tg in pairs

Message ID 20220701093441.885741-7-yukuai1@huaweicloud.com (mailing list archive)
State New, archived
Headers show
Series bugfix and cleanup for blk-throttle | expand

Commit Message

Yu Kuai July 1, 2022, 9:34 a.m. UTC 
From: Yu Kuai <yukuai3@huawei.com>

It's a litter weird to call throtl_dequeue_tg() unconditionally in
throtl_select_dispatch(), since it will be called in
tg_update_disptime() again if some bio is still throttled.

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
---
 block/blk-throttle.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

Tejun Heo July 27, 2022, 6:40 p.m. UTC | #1 
On Fri, Jul 01, 2022 at 05:34:39PM +0800, Yu Kuai wrote:
> From: Yu Kuai <yukuai3@huawei.com>
> 
> It's a litter weird to call throtl_dequeue_tg() unconditionally in
         ^
         little

> throtl_select_dispatch(), since it will be called in
> tg_update_disptime() again if some bio is still throttled.
> 
> Signed-off-by: Yu Kuai <yukuai3@huawei.com>

Maybe note that this doesn't create any functional differences in the
description?

Acked-by: Tejun Heo <tj@kernel.org>

Thanks.
diff mbox series

Patch

diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index e690dc1c1cde..ab30efedff4e 100644
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -1151,13 +1151,13 @@  static int throtl_select_dispatch(struct throtl_service_queue *parent_sq)
 		if (time_before(jiffies, tg->disptime))
 			break;
 
-		throtl_dequeue_tg(tg);
-
 		nr_disp += throtl_dispatch_tg(tg);
 
 		sq = &tg->service_queue;
 		if (sq->nr_queued[READ] || sq->nr_queued[WRITE])
 			tg_update_disptime(tg);
+		else
+			throtl_dequeue_tg(tg);
 
 		if (nr_disp >= THROTL_QUANTUM)
 			break;