Re: [PATCH 1/6] blk-mq: Do not invoke queue operations on a dead queue

[Bart Van Assche <Bart.VanAssche@sandisk.com>]

On Fri, 2017-04-14 at 00:40 -0700, Omar Sandoval wrote:
> On Thu, Apr 13, 2017 at 11:05:32PM +0000, Bart Van Assche wrote:
> > On Thu, 2017-04-13 at 16:01 -0700, Omar Sandoval wrote:
> > > Looking at this, I think we have similar issues with most of the othe=
r
> > > debugfs files. Should we move the debugfs cleanup earlier?
> >=20
> > That's a good question. However, while I was debugging it was very conv=
enient
> > to be able to access the queue state after it had reached the "dead" st=
ate.
> > Performing the cleanup earlier would be an alternative solution but wou=
ld
> > make debugging a bit harder ...
>=20
> What useful information were you getting out of debugfs once the queue
> was already dead? Wasn't the interesting stuff freed at that point?

Hello Omar,

I'm currently chasing a stall of dm-rq + dm-mpath that occurs after the
queues below it have reached the "dead" state. I will look for another
way to obtain the information I need such that we can remove the block
layer queue debugfs information before these queues reach the "dead"
state.

Bart.=