Re: [PATCH v2] blk-mq: fix a hung issue when set device state to blocked and restore running

To: Ming Lei <ming.lei@xxxxxxxxxx>, zhengbin <zhengbin13@xxxxxxxxxx>
Subject: Re: [PATCH v2] blk-mq: fix a hung issue when set device state to blocked and restore running
From: Bart Van Assche <bvanassche@xxxxxxx>
Date: Thu, 21 Mar 2019 06:51:21 -0700
Cc: jejb@xxxxxxxxxxxxx, martin.petersen@xxxxxxxxxx, jianchao.w.wang@xxxxxxxxxx, linux-scsi@xxxxxxxxxxxxxxx, houtao1@xxxxxxxxxx, yanaijie@xxxxxxxxxx, yuyufen@xxxxxxxxxx
In-reply-to: <20190321035538.GC15115@ming.t460p>
User-agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.5.2

On 3/20/19 8:55 PM, Ming Lei wrote:

I suggest to move blk_mq_run_hw_queues() out of the mutex for
avoiding any potential trouble.

Which trouble? I don't think any trouble can arise from holding a mutexaround a request to run a request queue asynchronously.


Bart.

References:
- [PATCH v2] blk-mq: fix a hung issue when set device state to blocked and restore running
  - From: zhengbin
- Re: [PATCH v2] blk-mq: fix a hung issue when set device state to blocked and restore running
  - From: Ming Lei