<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">I like this approach - it preserves the working code and the most common usage cases.<div><br></div><div>Bill</div><div><br><div>
<span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; "><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><div style="font-size: 12px; ">William Gropp</div><div style="font-size: 12px; ">Director, Parallel Computing Institute</div><div style="font-size: 12px; ">Deputy Director for Research</div><div style="font-size: 12px; ">Institute for Advanced Computing Applications and Technologies</div></div></div></span><span class="Apple-style-span" style="font-size: 12px; ">Thomas M. Siebel Chair in Computer Science</span><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><div style="font-size: 12px; ">University of Illinois Urbana-Champaign</div></div><div><br></div></div></span><br class="Apple-interchange-newline"></span><br class="Apple-interchange-newline">
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<br><div><div>On Dec 19, 2013, at 12:24 PM, Antonio J. Peña wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div><br>What about a mixed approach? If we've received no complaints so far that means that the current LUT is fine in most cases. We could fall into runtime computations if it's larger that that value. That will introduce a forced check, but the overhead will be lower than always computing, while the memory consumption would keep the same and the values not limited.<br><br> Toni<br><br><br>On 12/19/2013 11:13 AM, Jeff Hammond wrote:<br><blockquote type="cite">I started working on a patch, but I'm not sure if it is the right<br></blockquote><blockquote type="cite">thing to just encode a longer static array of primes.<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">Any suggestions on how to proceed? Should I generate the array of<br></blockquote><blockquote type="cite">primes on-the-fly (once per MPI instance) up to the max possible<br></blockquote><blockquote type="cite">amount?<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">Jeff<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">---------- Forwarded message ----------<br></blockquote><blockquote type="cite">From: Jeff Hammond <<a href="mailto:jeff.science@gmail.com">jeff.science@gmail.com</a>><br></blockquote><blockquote type="cite">Date: Thu, Dec 19, 2013 at 10:55 AM<br></blockquote><blockquote type="cite">Subject: Re: [mpich-discuss] MPI_Dims_create() fails for nproc >1000000<br></blockquote><blockquote type="cite">To: <a href="mailto:discuss@mpich.org">discuss@mpich.org</a><br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">Can you provide a short test that reproduces the issue you are seeing?<br></blockquote><blockquote type="cite"> I will add a Trac ticket for it.<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">Thanks,<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">Jeff<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">On Thu, Dec 19, 2013 at 9:49 AM, Andreas Schäfer <<a href="mailto:gentryx@gmx.de">gentryx@gmx.de</a>> wrote:<br></blockquote><blockquote type="cite"><blockquote type="cite">Hi,<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">I noticed that MPICH's MPI_Dims_create() fails with a floating point<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">exception, if the number of processes is larger than 10^6. Apparently<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">the reason is that the prime factors are hard coded into the code and<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">are limited to 1000 (or sqrt(10^6)). Open MPI's implementation has no<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">such limitation.<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">Best<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">-Andreas<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">--<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">==========================================================<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">Andreas Schäfer<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">HPC and Grid Computing<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">Chair of Computer Science 3<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">Friedrich-Alexander-Universität Erlangen-Nürnberg, Germany<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">+49 9131 85-27910<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">PGP/GPG key via keyserver<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><a href="http://www.libgeodecomp.org">http://www.libgeodecomp.org</a><br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">==========================================================<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">(\___/)<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">(+'.'+)<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">(")_(")<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">This is Bunny. Copy and paste Bunny into your<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">signature to help him gain world domination!<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">_______________________________________________<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">discuss mailing list <a href="mailto:discuss@mpich.org">discuss@mpich.org</a><br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">To manage subscription options or unsubscribe:<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><a href="https://lists.mpich.org/mailman/listinfo/discuss">https://lists.mpich.org/mailman/listinfo/discuss</a><br></blockquote></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">--<br></blockquote><blockquote type="cite">Jeff Hammond<br></blockquote><blockquote type="cite"><a href="mailto:jeff.science@gmail.com">jeff.science@gmail.com</a><br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite"><br></blockquote><br><br>-- <br>Antonio J. Peña<br>Postdoctoral Appointee<br>Mathematics and Computer Science Division<br>Argonne National Laboratory<br>9700 South Cass Avenue, Bldg. 240, Of. 3148<br>Argonne, IL 60439-4847<br><a href="mailto:apenya@mcs.anl.gov">apenya@mcs.anl.gov</a><br>www.mcs.anl.gov/~apenya<br><br></div></blockquote></div><br></div></body></html>