July 2015 - mpiwg-tools - mailman3.cels.anl.gov

Meeting reminder: Thursday, 8/30 11:00 AM EDT
by Kathryn Mohror 28 Jul '15

28 Jul '15

Hi all, This is a reminder of our regular tools WG telecon this Thursday at 8:00 AM PDT, 11:00 EDT. You can access the webex information from the wiki: https://svn.mpi-forum.org/trac/mpi-forum-web/wiki/MPI3Tools Agenda: QMPI Debugger topics (possibly) Kathryn _________________________________________________________________ Kathryn Mohror, kathryn(a)llnl.gov, http://scalability.llnl.gov/ Scalability Team @ Lawrence Livermore National Laboratory, Livermore, CA, USA

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Cancel tomorrow's meeting
by Kathryn Mohror 15 Jul '15

15 Jul '15

Hi all, It doesn't seem like we'll have enough folks attending the call tomorrow to make progress on our current topics, so I'm cancelling the meeting. Talk to you in a couple weeks! Kathryn _________________________________________________________________ Kathryn Mohror, kathryn(a)llnl.gov, http://scalability.llnl.gov/ Scalability Team @ Lawrence Livermore National Laboratory, Livermore, CA, USA

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Re: [mpiwg-tools] [Omp-tools] Tool initialization question
by John Mellor-Crummey 02 Jul '15

02 Jul '15

Martin, > [For MPI] 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. > > 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? Here’s why we chose the design for OpenMP where the OpenMP library invokes a function that the tool provides: The initial design for the OpenMP Tools API had the library publish various routines as part of its API (e.g., ompt_set_callback) and the tool would invoke these operations to register itself. When we tried using this design to profile UMT - an OpenMP application written at LLNL, this approach failed. The attached document has the details. I would be happy to elaborate or provide test cases to explain the problem further, if there are unresolved questions from the MPI tools group. The issue described in the attached document may not be a problem in practice for MPI applications. The ingredients that would cause the problem are (1) the MPI library is not linked into an executable, (2) the executable dlopens a dynamically loaded library that uses MPI. In that case, a preloaded tool wouldn’t be able to see the MPI library and register itself because of dynamic library symbol visibility rules. -- John Mellor-Crummey Professor Dept of Computer Science Rice University email: johnmc(a)rice.edu phone: 713-348-5179 > On Jul 2, 2015, at 11:55 AM, Schulz Martin <schulzm(a)llnl.gov> wrote: > > Oops, my autocomplete caught the old MPI list name. > > Please reply to this email not the first one. > > Thanks! > > Martin > > > ________________________________________________________________________ > Martin Schulz, schulzm(a)llnl.gov <mailto:[email protected]>, http://scalability.llnl.gov/ <http://scalability.llnl.gov/> > CASC @ Lawrence Livermore National Laboratory, Livermore, USA > > > From: Schulz Martin <schulzm(a)llnl.gov <mailto:[email protected]>> > Date: Thursday, July 2, 2015 at 9:50 AM > To: John Mellor-Crummey <johnmc(a)rice.edu <mailto:[email protected]>> > Cc: ext-omptools <omp-tools(a)openmp.org <mailto:[email protected]>>, MPI3 Tools Tools <mpi3-tools(a)lists.mpi-forum.org <mailto:[email protected]>> > Subject: [Omp-tools] Tool initialization question > > Hi John, > > (I am cc-ing both the MPI and the OMP tool lists, since this affects both – sorry for any duplicate emails this will cause) > > 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: > > 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. > > 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. > > 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? > > 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? > > Thanks! > > Martin > > > ________________________________________________________________________ > Martin Schulz, schulzm(a)llnl.gov <mailto:[email protected]>, http://scalability.llnl.gov/ <http://scalability.llnl.gov/> > CASC @ Lawrence Livermore National Laboratory, Livermore, USA > > !DSPAM:8504,55956d1417521104631228!

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Re: [mpiwg-tools] [Omp-tools] Tool initialization question
by Schulz Martin 02 Jul '15

02 Jul '15

Oops, my autocomplete caught the old MPI list name. Please reply to this email not the first one. Thanks! Martin ________________________________________________________________________ Martin Schulz, schulzm(a)llnl.gov, http://scalability.llnl.gov/ CASC @ Lawrence Livermore National Laboratory, Livermore, USA From: Schulz Martin <schulzm(a)llnl.gov> Date: Thursday, July 2, 2015 at 9:50 AM To: John Mellor-Crummey <johnmc(a)rice.edu> Cc: ext-omptools <omp-tools(a)openmp.org>, MPI3 Tools Tools <mpi3-tools(a)lists.mpi-forum.org> Subject: [Omp-tools] Tool initialization question Hi John, (I am cc-ing both the MPI and the OMP tool lists, since this affects both sorry for any duplicate emails this will cause) 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: 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 didn¹t go with it, since this prevents the ability to allow multiple tools. 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. 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 wasn¹t 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? Anyone else remember details on this and wants to comment as well? If the registration option doesn¹t work is there a third way that we could adopt for both standards that fulfills all criteria? Thanks! Martin ________________________________________________________________________ Martin Schulz, schulzm(a)llnl.gov, http://scalability.llnl.gov/ CASC @ Lawrence Livermore National Laboratory, Livermore, USA

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Re: [mpiwg-tools] QMPI status slides
by Jeff Squyres (jsquyres) 02 Jul '15

02 Jul '15

Thanks for your time today; I'm sorry we ran out of time. We amended the presentation Kathryn posted with some notes from the discussion today. I have posted the amended PPTX on the wiki: https://svn.mpi-forum.org/trac/mpi-forum-web/attachment/wiki/MPI3Tools/the-… > On Jun 29, 2015, at 11:50 AM, Kathryn Mohror <kathryn(a)llnl.gov> wrote: > > Hi all, > > In preparation for this week's meeting, I've put the current version of the > QMPI design slides up on the wiki. > > Look here: > https://svn.mpi-forum.org/trac/mpi-forum-web/wiki/MPI3Tools/the-new-pmpi > under "Attachments" at the bottom. Look for the most recent version. > > I didn't attach them to this email because sometimes people complain about > attachments clogging up their inboxes. However, if people want them as an > attachment, just let me know. > > Kathryn > _________________________________________________________________ > Kathryn Mohror, kathryn(a)llnl.gov, http://scalability.llnl.gov/ > Scalability Team @ Lawrence Livermore National Laboratory, Livermore, CA, > USA > > > > _______________________________________________ > mpiwg-tools mailing list > mpiwg-tools(a)lists.mpi-forum.org > http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-tools -- Jeff Squyres jsquyres(a)cisco.com For corporate legal information go to: http://www.cisco.com/web/about/doing_business/legal/cri/

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Re: [mpiwg-tools] Meeting reminder
by Marc-Andre Hermanns 01 Jul '15

01 Jul '15

Hi all, I won't be able to make the call. I am on leave for a couple of days without access to email. Cheers, Marc-Andre On 02.07.15 01:21, Kathryn Mohror wrote: > Hi all, > > Don't forget our meeting tomorrow at 11:00 AM EDT, 8:00 AM PDT. The webex > connection information is on the wiki: > https://svn.mpi-forum.org/trac/mpi-forum-web/wiki/MPI3Tools > > Agenda: > Touch base on debugger topics to see if anything has come up > QMPI discussion > > Talk to you soon! > Kathryn > > _________________________________________________________________ > Kathryn Mohror, kathryn(a)llnl.gov, http://scalability.llnl.gov/ > Scalability Team @ Lawrence Livermore National Laboratory, Livermore, CA, > USA > > > > _______________________________________________ > mpiwg-tools mailing list > mpiwg-tools(a)lists.mpi-forum.org > http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-tools > -- Marc-Andre Hermanns Jülich Aachen Research Alliance, High Performance Computing (JARA-HPC) German Research School for Simulation Sciences GmbH Schinkelstrasse 2 52062 Aachen Germany Phone: +49 2461 61 2509 Fax: +49 241 80 6 99753 www.grs-sim.de/parallel email: m.a.hermanns(a)grs-sim.de

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Meeting reminder
by Kathryn Mohror 01 Jul '15

01 Jul '15

Hi all, Don't forget our meeting tomorrow at 11:00 AM EDT, 8:00 AM PDT. The webex connection information is on the wiki: https://svn.mpi-forum.org/trac/mpi-forum-web/wiki/MPI3Tools Agenda: Touch base on debugger topics to see if anything has come up QMPI discussion Talk to you soon! Kathryn _________________________________________________________________ Kathryn Mohror, kathryn(a)llnl.gov, http://scalability.llnl.gov/ Scalability Team @ Lawrence Livermore National Laboratory, Livermore, CA, USA

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