[openib-general] posting send requests in RTR

[Michael S. Tsirkin]

Quoting r. Sean Hefty <sean.hefty at intel.com>:
> Subject: RE: posting send requests in RTR
> 
> >Not necessarily. CMA consumer at this point is a rare beast, but since the
> >issue
> >is not specific to CMA, let's look at some IB protocols: IPoIB connected mode
> >can simply drop a packet.  So can SRP.  SDP (potential CMA consumer!) simply
> >never needs to send any application data before communication established
> >event.
> >
> >Possibly some ULPs may need an extra queue - so let them handle the complexity.
> 
> If the ULP isn't sharing a CQ across multiple QPs, it could just wait to arm
> the CQ (followed by a poll) after receiving the connection establish event.  I
> think the shared CQ case is the more difficult one for the ULP to handle, and
> I don't know how many ULPs this affects.

You can queue receive completions in ULP and process them after the established
event.

If WR ID is a running index like in IPoIB you can just increment a counter.

It's up to the applications to decide which approach is better.

-- 
MST