[openib-general] [PATCH 1/2][RFC] Implement resize of CQ

[Hal Rosenstock]

On Thu, 2004-11-04 at 12:44, Krishna Kumar wrote:
> On Thu, 4 Nov 2004, Roland Dreier wrote:
> 
> > Not sure what the goal is here, but I should point out that current
> > mthca code does not implement resizing either CQs or QPs.
> 
> Yes, I agree on that. Infact the verbs layer will return ENOSYS for
> mthca driver. But I was assuming that any other driver by a different
> hardware vendor can support this call (mthca over time could support
> this call too ?).

Is this a driver or firmware issue ?

> > However I'm not sure I understand why the MAD layer wants to resize
> > these objects -- given that the number of QPs is known in advance and
> > that the MAD layer can choose how many work requests to post per QP,
> > I'm not sure what is gained by trying to resize things dynamically.
> 
> Actually, I haven't really implemented the "dynamically" part, where you
> resize the CQ during operation. The spec said that when you create a QP,
> it can be larger than what you specified. If so, I see good value in
> increasing the size of the associated CQ, if it is supported by the
> driver.

Might this be useful for redirected QPs ?

Should the incorporation of this functionality be deferred until either
there is hardware which supports this or we find some use for it ?

-- Hal