[ofa-general] mthca wc->opcode for CQEs with error status

[Todd Rimmer]

Roland,

> From: Roland Dreier [mailto:rdreier at cisco.com]
> 
> If this were some feature that allowed us to do something new, or made
> applications more efficient, or something like that, I'd be all for
> it, specs be damned.  But in this case it's just bloating driver code
> to work around buggy applications.  And I'd rather use my I$ for
> something more useful.  (And in fact the proposed change is itself
> buggy -- it calls any completion on the send queue a send, even if it
> was actually something else like RDMA read/write, atomic, etc)
> 

>From a pure technical point of view, I agree 100% with all your
comments.  In fact I had alluded to all these issues in the original 1
line submission.

However, I think you are missing the point.

<soapbox>
In order for Infiniband to be successful, it must expand the set of
applications which it can run.  This often means making technical
compromises to permit expanded market share.

In the case in point, I'm working with a 3rd party whose application
already was ported to VAPI, the SilverStorm stack, and will work on
OFED/ipath.
In the interest of cooperation, I'm trying to help so that OFED/mthca
can also run this application.

Telling the customer they must redesign the application for OFED/mthca,
is not practical and certainly does not promote a positive view of
Infiniband for the market.  Yes the application is not perfect, yes it
should be rewritten, but the customer can just as easily move to other
alternatives.  We need to promote IB in the marketplace, not admonish
customers who are trying to use it.

It is this lack of portability of applications which has significantly
hurt infiniband's reputation in the market.  While its nice to focus on
building the perfect implementation, sometimes compromises are necessary
to ensure the overall success of the technology.  VHS vs Beta is a
perfect example.
</soapbox>

Todd Rimmer
Chief Architect
QLogic System Interconnect Group
Voice: 610-233-4852     Fax: 610-233-4777
Todd.Rimmer at QLogic.com  www.QLogic.com