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From:   Yu Kuai <yukuai3@huawei.com>
To:     tj@kernel.org, mkoutny@suse.com, axboe@kernel.dk,
        ming.lei@redhat.com
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        linux-kernel@vger.kernel.org, yukuai3@huawei.com,
        yukuai1@huaweicloud.com, yi.zhang@huawei.com
Subject: [PATCH v6 6/8] blk-throttle: calling throtl_dequeue/enqueue_tg in pairs
Date:   Fri,  1 Jul 2022 15:49:21 +0800
Message-Id: <20220701074923.657426-8-yukuai3@huawei.com>
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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(-)

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;
-- 
2.31.1