Re: [PATCH 1/1] block: Use RCU in blk_mq_[un]quiesce_tagset() instead of set->tag_list_lock

Bart Van Assche
2025-12-04T19:07:06Z

On 12/4/25 8:42 AM, Mohamed Khalfella wrote:
> Is blk_mq_del_queue_tag_set() performance sensitive such that it can not
> take synchronize_rcu()? It is not in IO codepath, right?

Introducing a new synchronize_rcu() call almost always slows down some
workload so it should be avoided if possible.

> I can not think of an easy way to do that. Suggestions are welcomed.

I can't find the implementation of nvme_dev_disable_locked(). What
kernel tree does your patch apply to?

$ git grep -w nvme_dev_disable_locked axboe-block/for-next | wc -l
0

Thanks,

Bart.