[ofa-general] post_recv question

[Gleb Natapov]

On Thu, Feb 21, 2008 at 11:44:07AM -0800, Ralph Campbell wrote:
> > > That is why the IB RC protocol does this for you in band if the RC QP
> > > is using a dedicated receive queue but not a shared receive queue.
> > What do you mean by that? RNR works for both RC and SRQ QPs.
> 
> Right.
> I was referring to the credit returned in the ACK header which
> allows the remote RC QP endpoint to send a message after a post_recv().
> There is no such message level flow control if the RC QP is using a SRQ.
Ah, you are talking about that flow control. But the purpose of that flow
control is to rate limit a sender in case of receive buffers shortage,
not to prevent RNRs completely.

--
			Gleb.