<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; color: rgb(0, 0, 0); font-size: 14px; font-family: Calibri, sans-serif;"><div><div><div>Oops, my autocomplete caught the old MPI list name.</div><div><br></div><div>Please reply to this email not the first one.</div><div><br></div><div>Thanks!</div><div><br></div><div>Martin</div><div><br></div><div><br></div><div><div style="font-family: Consolas; font-size: medium;">________________________________________________________________________</div><div style="font-family: Consolas; font-size: medium;">Martin Schulz, <a href="mailto:schulzm@llnl.gov">schulzm@llnl.gov</a>, <a href="http://scalability.llnl.gov/">http://scalability.llnl.gov/</a></div><div style="font-family: Consolas; font-size: medium;">CASC @ Lawrence Livermore National Laboratory, Livermore, USA</div><div><br></div></div></div></div><div><br></div><span id="OLK_SRC_BODY_SECTION"><div style="font-family:Calibri; font-size:11pt; text-align:left; color:black; BORDER-BOTTOM: medium none; BORDER-LEFT: medium none; PADDING-BOTTOM: 0in; PADDING-LEFT: 0in; PADDING-RIGHT: 0in; BORDER-TOP: #b5c4df 1pt solid; BORDER-RIGHT: medium none; PADDING-TOP: 3pt"><span style="font-weight:bold">From: </span> Schulz Martin <<a href="mailto:schulzm@llnl.gov">schulzm@llnl.gov</a>><br><span style="font-weight:bold">Date: </span> Thursday, July 2, 2015 at 9:50 AM<br><span style="font-weight:bold">To: </span> John Mellor-Crummey <<a href="mailto:johnmc@rice.edu">johnmc@rice.edu</a>><br><span style="font-weight:bold">Cc: </span> ext-omptools <<a href="mailto:omp-tools@openmp.org">omp-tools@openmp.org</a>>, MPI3 Tools Tools <<a href="mailto:mpi3-tools@lists.mpi-forum.org">mpi3-tools@lists.mpi-forum.org</a>><br><span style="font-weight:bold">Subject: </span> [Omp-tools] Tool initialization question<br></div><div><br></div><div><meta http-equiv="Content-Type" content="text/html; charset=utf-8"><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; color: rgb(0, 0, 0); font-size: 14px; font-family: Calibri, sans-serif;"><div>Hi John,</div><div><br></div><div>(I am cc-ing both the MPI and the OMP tool lists, since this affects both – sorry for any duplicate emails this will cause)</div><div><br></div><div>We had an MPI tools group call this morning and talked once again about tool initialization. The current proposals for the two standards are currently different:</div><div><br></div><div>In OpenMP, we rely on a known symbol that the OpenMP runtime looks for and then calls when it is ready to initialize the tool. We talked about this for MPI, but didn’t go with it, since this prevents the ability to allow multiple tools.</div><div><br></div><div>We therefore picked an approach where the tool registers itself once it gets invoked somehow (e.g., in library initialization routines) and then MPI can do the actual initialization of all registered tools during MPI_Init. This allows as many tools to
register themselves as needed.</div><div><br></div><div>However, when I brought this up at the last OMPT call, you mentioned that this would cause problem with linking since the runtime system may not be visible, yet, when the registration call gets loaded. When we talked about this today, it wasn’t clear to
us anymore, though, why this would be a problem, since the call the registration function simply could load the runtime (assuming its a shared library). Can you elaborate a bit more of why this is problematic?</div><div><br></div><div>Anyone else remember details on this and wants to comment as well? If the registration option doesn’t work is there a third way that we could adopt for both standards that fulfills all criteria?</div><div><br></div><div>Thanks!</div><div><br></div><div>Martin</div><div><br></div><div><br></div><div><div style="font-family: Consolas; font-size: medium;">________________________________________________________________________</div><div style="font-family: Consolas; font-size: medium;">Martin Schulz, <a href="mailto:schulzm@llnl.gov">schulzm@llnl.gov</a>, <a href="http://scalability.llnl.gov/">http://scalability.llnl.gov/</a></div><div style="font-family: Consolas; font-size: medium;">CASC @ Lawrence Livermore National Laboratory, Livermore, USA</div><div><br></div></div></div></div></span></body></html>