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Subject: Re: [OMPI devel] matching code rewrite in OB1
From: Gleb Natapov (glebn_at_[hidden])
Date: 2007-12-11 11:23:28


On Tue, Dec 11, 2007 at 08:03:52AM -0800, Andrew Friedley wrote:
> Try UD, frags are reordered at a very high rate so should be a good test.
Good Idea I'll try this. BTW I thing the reason for such a high rate of
reordering in UD is that it polls for MCA_BTL_UD_NUM_WC completions
(500) and process them one by one and if progress function is called
recursively next 500 completion will be reordered versus previous
completions (reordering happens on a receiver, not sender).

>
> Andrew
>
> Richard Graham wrote:
> > Gleb,
> > I would suggest that before this is checked in this be tested on a system
> > that has N-way network parallelism, where N is as large as you can find.
> > This is a key bit of code for MPI correctness, and out-of-order operations
> > will break it, so you want to maximize the chance for such operations.
> >
> > Rich
> >
> >
> > On 12/11/07 10:54 AM, "Gleb Natapov" <glebn_at_[hidden]> wrote:
> >
> >> Hi,
> >>
> >> I did a rewrite of matching code in OB1. I made it much simpler and 2
> >> times smaller (which is good, less code - less bugs). I also got rid
> >> of huge macros - very helpful if you need to debug something. There
> >> is no performance degradation, actually I even see very small performance
> >> improvement. I ran MTT with this patch and the result is the same as on
> >> trunk. I would like to commit this to the trunk. The patch is attached
> >> for everybody to try.
> >>
> >> --
> >> Gleb.
> >> _______________________________________________
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> >> devel_at_[hidden]
> >> http://www.open-mpi.org/mailman/listinfo.cgi/devel
> >
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--
			Gleb.