Re: [Myrinet] Using mpd with gm apps in mpich-1.2.4..8a (performance difference)

Thanks for the info.
I didn't have mpd installed right and all the processes
were starting on one node.

Craig

On Mon, Sep 16, 2002 at 02:08:18PM -0400, Patrick Geoffray wrote:
> Hi Craig,
> 
> On Tue, 2002-09-10 at 17:30, Craig Tierney wrote: 
> > I am trying to configure my cluster to run
> > using the MPD process to help speedup large
> > The bandwidth is about 1/2 of what I expect and
> > the latency is about 50% worse when using mpd to
> > start the program.  Am I doing something wrong?
> 
> I get identical results with or without MPD. It's as expected because
> MPD is involved only at startup time. 
> 
> > #p0     p1      dist    len     ave time (us)   rate
> > 0       1       1       0       14.569375       0.00
> > 0       1       1       1048576 7687.510000     136.400e+6
> 
> It looks like loopback performance instead of point-to-point. Are you
> sure that the 2 processes are spawned on 2 different nodes ?
> BTW, "-y" is specific to the Myrinet usage at ANL, it's useless for
> MPICH-GM.
> 
> You can do 2 things: 
> * check that the processes are effectively spawned on 2 different nodes
> (print the host name in the mpptest code). 
> * check that no other previous mpptest instances are still running on
> the same nodes. 
> 
> I have tried to reproduce your case in many many ways, without success.
> 
> Patrick 
> -- 
> ----------------------------------------------------------
> |   Patrick Geoffray, Ph.D.      [email protected] 
> |   Myricom, Inc.                http://www.myri.com
> |   Cell:  865-389-8852          685 Emory Valley Rd (B)
> |   Phone: 626-821-5555          Oak Ridge, TN 37830
> ----------------------------------------------------------

-- 
Craig Tierney ([email protected])