<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">I also have an O(log Nproc) implementation that I've been using for some time.<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 Jul 3, 2013, at 11:02 AM, Jeff Hammond wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div><a href="https://wiki.alcf.anl.gov/parts/index.php/Implementing_a_Symmetric_Heap">https://wiki.alcf.anl.gov/parts/index.php/Implementing_a_Symmetric_Heap</a> has an implementation of MPE_Comm_split_node that does a very simple O(Nproc) implementation of MPI_Comm_split_type(type=SHARED) using MPI_Get_processor_name. It also shows the non-portable implementation for Cray and Blue Gene that one can use until MPI-3 is deployed on those systems.<br><br>Jim Dinan wrote an O(log Nproc) implementation of MPI_Comm_split_type(type=SHARED) that I have somewhere but I don't like it because it's confusing to my small brain.<br><br>Jeff<br><br>----- Original Message -----<br>From: "Rob Latham" <<a href="mailto:robl@mcs.anl.gov">robl@mcs.anl.gov</a>><br>To: <a href="mailto:devel@mpich.org">devel@mpich.org</a><br>Sent: Wednesday, July 3, 2013 10:53:15 AM<br>Subject: Re: [mpich-devel] find out what processes are on the same node<br><br>On Wed, Jul 03, 2013 at 10:39:55AM -0500, Tatiana V. Martsinkevich wrote:<br><blockquote type="cite">Hello,<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">I have a couple of questions:<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">1) is there a way to find out what other processes reside in the same<br></blockquote><blockquote type="cite">node as my_rank from within MPICH?<br></blockquote><br>MPI_GET_PROCESSOR_NAME might be what you are looking for. <br><br>==rob<br><br>-- <br>Rob Latham<br>Mathematics and Computer Science Division<br>Argonne National Lab, IL USA<br><br>-- <br>Jeff Hammond<br>Argonne Leadership Computing Facility<br>University of Chicago Computation Institute<br><a href="mailto:jhammond@alcf.anl.gov">jhammond@alcf.anl.gov</a> / (630) 252-5381<br><a href="http://www.linkedin.com/in/jeffhammond">http://www.linkedin.com/in/jeffhammond</a><br>https://wiki.alcf.anl.gov/parts/index.php/User:Jhammond<br>ALCF docs: http://www.alcf.anl.gov/user-guides<br></div></blockquote></div><br></div></body></html>