[dm-devel] [PATCH 4/7] dm mpath: remove process_queued_ios()

[Hannes Reinecke]

On 02/11/2014 04:55 PM, Mike Snitzer wrote:
> On Tue, Feb 11 2014 at  4:46am -0500,
> Hannes Reinecke <hare at suse.de> wrote:
>
>> On 02/10/2014 02:30 PM, Mike Snitzer wrote:
>>>
>>> Just to verify, this seems to be the only outstanding question for this
>>> patchset?
>>>
>>> What value are you using for HZ?  If this portion of the change does
>>> turn out to be meaningul: Rather than tieing to HZ should we just use an
>>> explicitly non-zero value for __pg_init_all_paths()'s @min_delay?
>>>
>> The actual amount here is irrelevant, as long as it's non-zero.
>> It's just there to force execution of the work item off the current
>> thread.
>
> I'm aware we just need a non-zero value.  My concern, as originally
> raised by Junichi in an earlier reply when you had it as HZ/50, is that
> the value could be 0 if HZ is really small.  While unlikely I see no
> point allowing the variable nature of HZ compromise passing a non-zero
> value here.  Best to just be explicit by passing 1 or something.
>
> All said, the question of why this is actually needed remains.  I trust
> you're working on answering that via reproducer (by not forcing the use
> of workqueue context)?
>
Precisely.

But as this is a bit hard to trigger it might take some time.
(you'll only be hitting this issue if you have to retry 
scsi_dh_activate, so you'll need to trigger this somehow).

I hope to get it done this week.
Is there any deadline which I might miss with that?

Cheers,

Hannes
-- 
Dr. Hannes Reinecke		      zSeries & Storage
hare at suse.de			      +49 911 74053 688
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: J. Hawn, J. Guild, F. Imendörffer, HRB 16746 (AG Nürnberg)