Hi.

On 11.08.2018 14:23, Ming Lei wrote:
> Please test for-4.19/block:
> 
> https://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux-block.git/log/?h=for-4.19/block
> 
> This slow boot issue should have been fixed by the following commits:
> 
> 1311326cf475 blk-mq: avoid to synchronize rcu inside 
> blk_cleanup_queue()
> 97889f9ac24f blk-mq: remove synchronize_rcu() from 
> blk_mq_del_queue_tag_set()
> 5815839b3ca1 blk-mq: introduce new lock for protecting 
> hctx->dispatch_wait
> 2278d69f030f blk-mq: don't pass **hctx to blk_mq_mark_tag_wait()
> 8ab6bb9ee8d0 blk-mq: cleanup blk_mq_get_driver_tag()

Indeed, I can confirm that these commits fix the issue.

Thanks a lot.

-- 
   Oleksandr Natalenko (post-factum)