Re: [PATCH] blk-mq: clear active_queues before clearing BLK_MQ_F_TAG_QUEUE_SHARED

On 7/31/21 12:21 AM, Yu Kuai wrote:

We run a test that delete and recover devcies frequently(two devices on
the same host), and we found that 'active_queues' is super big after a
period of time.

If device a and device b share a tag set, and a is deleted, then
blk_mq_exit_queue() will clear BLK_MQ_F_TAG_QUEUE_SHARED because there
is only one queue that are using the tag set. However, if b is still
active, the active_queues of b might never be cleared even if b is
deleted.

Thus clear active_queues before BLK_MQ_F_TAG_QUEUE_SHARED is cleared.

Applied, thanks.

-- 
Jens Axboe