Re: queue_depth tracking from LLD

[James Smart <James.Smart@Emulex.Com>]

Christof Schmitt wrote:
> zfcp is one of the drivers that don't have ramp-up/down mechanism in
> place. And i am trying to understand what is required here.  Is there
> currently work being done to get queue_depth ramp-up/down in the
> midlayer?

No work started - but desired.

I'd recommend, rather than implementing it in zfcp, implement it in the
midlayer for everyone.

> 
>>> If we moved code like that to the scsi layer, then is all the is needed 
>>> is a interface to config this?
> 
>> Yep. As mentioned, figuring out what algorithm, for what device and
>> configuration, will be the more interesting thing.
> 
> If the LLDs that currently have a private ramp-up/down mechanism in
> place use a similar strategy, would it make sense to first move them
> to common code that can be activated from a LLD? And later refine it
> with device-specific behaviour?

Yes.

-- james s