On Wed, 2006-02-08 at 19:10 +0200, Michael S. Tsirkin wrote: > Quoting r. Sean Hefty <[EMAIL PROTECTED]>: > > Subject: RE: [openib-general] Re: [PATCH] [RFC] - example user mode > > rdmaping/pongprogram using CMA > > > > >Steve, looks like you have at most a single receive work request posted at > > >the > > >receive workqueue at all times. > > >If true, this is *really* not a good idea, performance-wise, even if you > > >actually have at most 1 packet in flight. > > > > Can you provide some more details on this? > > See 9.7.7.2 end-to-end (message level) flow control >
I just read this section in the 1.2 version of the spec, and I still don't understand what the issue really is? 9.7.7.2 talks about IBA doing flow control based on the RECV WQEs posted. rping always ensures that there is a RECV posted before the peer can send. This is ensured by the rping protocol itself (see the comment at the front of rping.c describing the ping loop). I'm only ever sending one outstanding message via SEND/RECV. I would rather post exactly what is needed, than post some number of RECVs "just to be safe". Sorry if I'm being dense. What am I missing here? Steve. _______________________________________________ openib-general mailing list [email protected] http://openib.org/mailman/listinfo/openib-general To unsubscribe, please visit http://openib.org/mailman/listinfo/openib-general
