Re: [PATCHSET v5] blk-mq: reimplement timeout handling

From: Ming Lei
Date: Sun Jan 14 2018 - 10:45:23 EST


On Sun, Jan 14, 2018 at 11:12 PM, jianchao.wang
<jianchao.w.wang@xxxxxxxxxx> wrote:
>
>
> On 01/13/2018 05:19 AM, Bart Van Assche wrote:
>> Sorry but I only retrieved the blk-mq debugfs several minutes after the hang
>> started so I'm not sure the state information is relevant. Anyway, I have attached
>> it to this e-mail. The most remarkable part is the following:
>>
>> ./000000009ddfa913/requeue_list:000000009646711c {.op=READ, .state=idle, gen=0x1
>> 18, abort_gen=0x0, .cmd_flags=, .rq_flags=SORTED|1|SOFTBARRIER|IO_STAT, complete
>> =0, .tag=-1, .internal_tag=217}
>>
>> The hexadecimal number at the start is the request_queue pointer (I modified the
>> blk-mq-debugfs code such that queues are registered with there address just after
>> creation and until a name is assigned). This is a dm-mpath queue.
>
> There seems to be something wrong in hctx->nr_active.

Then looks it is same with the issue I saw during starting multipathd, and the
following patch should fix that, if there isn't other issue.

https://marc.info/?l=linux-block&m=151586577400558&w=2

--
Ming Lei