On Wed, Oct 13, 2021 at 08:44:56PM +0800, Yu Kuai wrote: > @@ -1401,6 +1406,7 @@ void blkcg_deactivate_policy(struct request_queue *q, > if (queue_is_mq(q)) > blk_mq_freeze_queue(q); > > + mutex_lock(&q->blkg_lock); > spin_lock_irq(&q->queue_lock); Given that deactivation drains q_usage_counter through blk_mq_freeze_queue(), can't the blkg_conf_prep() just pin the usage count? Thanks. -- tejun
