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Subject: Re: [OMPI devel] Threaded progress for CPCs
From: Gleb Natapov (glebn_at_[hidden])
Date: 2008-05-19 10:17:57

On Mon, May 19, 2008 at 05:08:17PM +0300, Pavel Shamis (Pasha) wrote:
> >> 5. ...?
> >>
> > What about moving posting of receive buffers into main thread. With
> > SRQ it is easy: don't post anything in CPC thread. Main thread will
> > prepost buffers automatically after first fragment received on the
> > endpoint (in btl_openib_handle_incoming()).
> It still doesn't guaranty that we will not see RNR (as I understand we
> trying to resolve this problem for iwarp?!)
I don't think that iwarp has SRQ at all. And if it has then it should
have HW flow control for it too. I don't see what advantage SRQ without
flow control can provide over PPRQ.

> So this solution will cost 1 buffer on each srq ... sounds acceptable
> for me. But I don't see too much
> difference compared to #1, as I understand we anyway will be need the
> pipe for communication with main thread.
> so why don't use #1 ?
What communication? No communication at all. Just don't prepost buffers
to SRQ during connection establishment. Problem solved (only for SRQ of