block-mq: fix comments in blk_mq_queue_tag_busy_iter
'f5bbbbe4d635 ("blk-mq: sync the update nr_hw_queues with blk_mq_queue_tag_busy_iter")' introduce a bug what we may sleep between rcu lock. Then '530ca2c9bd69 ("blk-mq: Allow blocking queue tag iter callbacks")' fix it by get request_queue's ref. And 'a9a808084d6a ("block: Remove the synchronize_rcu() call from __blk_mq_update_nr_hw_queues()")' remove the synchronize_rcu in __blk_mq_update_nr_hw_queues. We need update the confused comments in blk_mq_queue_tag_busy_iter. Signed-off-by: yangerkun <yangerkun@huawei.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
parent
8229cca8c3
commit
76cffccd60
|
@ -416,9 +416,7 @@ void blk_mq_queue_tag_busy_iter(struct request_queue *q, busy_iter_fn *fn,
|
|||
/*
|
||||
* __blk_mq_update_nr_hw_queues() updates nr_hw_queues and queue_hw_ctx
|
||||
* while the queue is frozen. So we can use q_usage_counter to avoid
|
||||
* racing with it. __blk_mq_update_nr_hw_queues() uses
|
||||
* synchronize_rcu() to ensure this function left the critical section
|
||||
* below.
|
||||
* racing with it.
|
||||
*/
|
||||
if (!percpu_ref_tryget(&q->q_usage_counter))
|
||||
return;
|
||||
|
|
Loading…
Reference in New Issue