Re: [PATCH] queue stall with blk-mq-sched

On 01/24/2017 08:54 AM, Hannes Reinecke wrote:

Hi Jens,

I'm trying to debug a queue stall with your blk-mq-sched branch; with my
latest mpt3sas patches fio stops basically directly after starting a
sequential read :-(

I've debugged things and came up with the attached patch; we need to
restart waiters with blk_mq_tag_idle() after completing a tag.
We're already calling blk_mq_tag_busy() when fetching a tag, so I think
calling blk_mq_tag_idle() is required when retiring a tag.

I'll take a look at this. It sounds like all your grief is related to
shared tag maps, which I don't have anything that uses here. I'll see
if we are leaking it, you should be able to check that by reading the
'active' file in the sysfs directory.

-- 
Jens Axboe