November 2009 - petsc-dev - mailman3.cels.anl.gov

Re: -malign-double
by Barry Smith 14 Nov '09

14 Nov '09

On Nov 14, 2009, at 11:28 AM, Jed Brown wrote: > Barry Smith wrote: >> >> >> Good point, I have removed it. >> >> I put it in because I wanted an easy way to test that PETSc double >> arrays are always 8 byte aligned (and the unaligned struct values >> were >> giving me lots of false alarms). > > A related issue is PetscMallocN which (in optimized mode) gives > unaligned arrays even if malloc always returns aligned memory. > Consider > > PetscMalloc2(3,PetscInt,&ai,3,PetscScalar,&a); This call is illegal. You are required to pass the longest aligned arrays first leading the shortest. Hence The PetscScalar should be before the PetscInt. The debug mode should check that this requirement is satisfied; it currently does not check anything. In the real world when any of these beasts can be 32 bit or 64 bit one cannot always put them in the right order; but for now they should be ordered, PetscScalar, pointer, PetscInt Barry > > I think it is preferable for PetscMallocN to align all the pointers. > > Jed >

1 0

Re: -malign-double
by Jed Brown 14 Nov '09

14 Nov '09

Barry Smith wrote: > > > Good point, I have removed it. > > I put it in because I wanted an easy way to test that PETSc double > arrays are always 8 byte aligned (and the unaligned struct values were > giving me lots of false alarms). A related issue is PetscMallocN which (in optimized mode) gives unaligned arrays even if malloc always returns aligned memory. Consider PetscMalloc2(3,PetscInt,&ai,3,PetscScalar,&a); I think it is preferable for PetscMallocN to align all the pointers. Jed

1 0

Re: -malign-double
by Barry Smith 13 Nov '09

13 Nov '09

Good point, I have removed it. I put it in because I wanted an easy way to test that PETSc double arrays are always 8 byte aligned (and the unaligned struct values were giving me lots of false alarms). I guess we can test for double align on x86_64 systems. Barry The IBM BlueGene doesn't like 4 byte aligned doubles and sends a bus error after a certain number are generated, Thus I was motivated to make PETSc a bit clearer on that. On Nov 12, 2009, at 9:29 AM, Lisandro Dalcin wrote: > On Wed, Nov 11, 2009 at 11:02 PM, Barry Smith <bsmith(a)mcs.anl.gov> > wrote: >> >> Satish, >> >> gcc supports the option -malign-double on some systems. Please >> add it to >> the flags that configure checks for c and c++ and have it added if it >> exists. >> > > Definitely -1. Why are you asking for this? On x86_64 this is the > default. In i386, this flag is likely going to break ABI's. > > > -- > Lisandro Dalcín > --------------- > Centro Internacional de Métodos Computacionales en Ingeniería (CIMEC) > Instituto de Desarrollo Tecnológico para la Industria Química (INTEC) > Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) > PTLC - Güemes 3450, (3000) Santa Fe, Argentina > Tel/Fax: +54-(0)342-451.1594

1 0

Fwd: [computational.science] CFP: Workshop on Large-Scale Parallel Processing (LSPP'10)
by Matthew Knepley 13 Nov '09

13 Nov '09

---------- Forwarded message ---------- From: Robert A. van de Geijn <rvdg(a)cs.utexas.edu> Date: Fri, Nov 13, 2009 at 3:21 PM Subject: Fwd: [computational.science] CFP: Workshop on Large-Scale Parallel Processing (LSPP'10) To: flame_cs(a)cs.utexas.edu Begin forwarded message: *From: *Darren Kerbyson <djk(a)lanl.gov> *Date: *November 13, 2009 9:17:55 AM CST *To: *Computational Science Mailing List < computational.science(a)lists.iccsa.org> *Subject: **[computational.science] CFP: Workshop on Large-Scale Parallel Processing (LSPP'10)* [Please accepts our apologies if you receive multiple copies] ----------------------------------------------------------------- Call for papers: Workshop on LARGE-SCALE PARALLEL PROCESSING to be held in conjunction with IEEE International Parallel and Distributed Processing Symposium Atlanta, Georgia April 23rd, 2010 SUBMISSION DEADLINE: December 14th 2009 Selected work presented at the workshop will be published in a special issue of Parallel Processing Letters. ----------------------------------------------------------------- The workshop on Large-Scale Parallel Processing is a forum that focuses on computer systems that utilize thousands of processors and beyond. This is a very active area given the goals of many researchers world-wide to enhance science-by-simulation through installing large-scale multi-petaflop systems at the start of the next decade. Large-scale systems, referred to by some as extreme-scale and Ultra-scale, have many important research aspects that need detailed examination in order for their effective design, deployment, and utilization to take place. These include handling the substantial increase in multi-core on a chip, the ensuing interconnection hierarchy, communication, and synchronization mechanisms. The workshop aims to bring together researchers from different communities working on challenging problems in this area for a dynamic exchange of ideas. Work at early stages of development as well as work that has been demonstrated in practice is equally welcome. Of particular interest are papers that identify and analyze novel ideas rather than providing incremental advances in the following areas: - LARGE-SCALE SYSTEMS : exploiting parallelism at large-scale, the coordination of large numbers of processing elements, synchronization and communication at large-scale, programming models and productivity - MULTI-CORE : utilization of increased parallelism on a single chip (MPP on a chip such as the Cell and GPUs), the possible integration of these into large-scale systems, and dealing with the resulting hierarchical connectivity. - NOVEL ARCHITECTURES AND EXPERIMENTAL SYSTEMS : the design of novel systems, the use of processors in memory (PIMS), parallelism in emerging technologies, future trends. - APPLICATIONS : novel algorithmic and application methods, experiences in the design and use of applications that scale to large-scales, overcoming of limitations, performance analysis and insights gained. Results of both theoretical and practical significance will be considered, as well as work that has demonstrated impact at small-scale that will also affect large-scale systems. Work may involve algorithms, languages, various types of models, or hardware. ----------------------------------------------------------------- SUBMISSION GUIDELINES Papers should not exceed eight single-space pages (including figures, tables and references) using a 12-point font on 8.5x11 inch pages. Submissions in PostScript or PDF should be made using EDAS (www.edas.info) Informal enquiries can be made to djk(a)lanl.gov. Submissions will be judged on correctness, originality, technical strength, significance, presentation quality and appropriateness. Submitted papers should not have appeared in or under consideration for another venue. IMPORTANT DATES Submission deadline: December 14th 2009 Notification of acceptance: January 15th 2010 Camera-Ready Papers due: February 1st 2010 ----------------------------------------------------------------- WORKSHOP CO-CHAIRS Darren J. Kerbyson Los Alamos National Laboratory Ram Rajamony IBM Austin Research Lab Charles Weems University of Massachusetts STEERING COMMITTEE Johnnie Baker Kent State University Alex Jones University of Pittsburgh H.J. Siegel Colorado State University PROGRAM COMMITTEE Ghoerge Almasi IBM T.J. Watson Research Lab Taisuke Boku University of Tsukuba, Japan Marco Daneluto University of Pisa Martin Herbordt Boston University Lei Huang University of Houston Daniel Katz University of Chicago Jesus Labarta Barcelona Supercomputer Center, Spain John Michalakes NCAR, Boulder Celso Mendes University of Illinois Urbana-Champagne Bernd Mohr Forschungszentrum Juelich, Germany Stathis Papaefstathiou Microsoft Michael Scherger Texas A&M University-Corpus Christi Harvey Wasserman NERSC/LBNL Gerhard Wellein University of Erlangen, Germany Pat Worley Oak Ridge National Laboratory Workshop Webpage: http://www.ccs3.lanl.gov/LSPP --------------------------------------------------------------------- To unsubscribe, e-mail: computational.science-unsubscribe(a)lists.iccsa.org For additional commands, e-mail: computational.science-help(a)lists.iccsa.org -- What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead. -- Norbert Wiener

1 0

Re: who broke PCFieldSplit code in petsc-dev?????????
by Barry Smith 12 Nov '09

12 Nov '09

Great, thanks, Barry On Nov 11, 2009, at 9:14 PM, Satish Balay wrote: > On Wed, 11 Nov 2009, Barry Smith wrote: > >> If we were smart we would keep the results of each nights nightly >> builds and >> then we could easily check what DAY things broke. Satish please >> have it save >> the old days stuff for each day. > > Ok - I've changed the crontab to move the logfiles into > http://ftp.mcs.anl.gov/pub/petsc/nightlylogs/archive/DATE > > Here date should be in the form 2009-Nov-11 > > Satish

1 0

Re: -malign-double
by Lisandro Dalcin 12 Nov '09

12 Nov '09

On Wed, Nov 11, 2009 at 11:02 PM, Barry Smith <bsmith(a)mcs.anl.gov> wrote: > > Satish, > > gcc supports the option -malign-double on some systems. Please add it to > the flags that configure checks for c and c++ and have it added if it > exists. > Definitely -1. Why are you asking for this? On x86_64 this is the default. In i386, this flag is likely going to break ABI's. -- Lisandro Dalcín --------------- Centro Internacional de Métodos Computacionales en Ingeniería (CIMEC) Instituto de Desarrollo Tecnológico para la Industria Química (INTEC) Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) PTLC - Güemes 3450, (3000) Santa Fe, Argentina Tel/Fax: +54-(0)342-451.1594

1 0

Re: who broke PCFieldSplit code in petsc-dev?????????
by Jed Brown 12 Nov '09

12 Nov '09

Barry Smith wrote: > A couple of weeks ago these examples ran fine and did not crash. Now > they crash. Perhaps it was not a change to fieldsplit that caused the > recent crashes, but it is a recent change to something. Indeed, but I am still responsible. When I changed MatSetBlockSize to not error when called (with compatible bs) on BAIJ, I forgot to actually change the block size for the MPI* matrices, just for a->A and a->B. Can we run TESTEXAMPLES_DATAFILESPATH in the nightlies? Note that PETSC_MAT_LIB does not depend on PETSC_DM_LIB. This is violated in mhyp.c, all over impls/adic (but I never got ADIC working), and in tests/ex96.c (which can be trivially moved to dm/da/examples/tests). This breaks anything that tries to link against PETSC_MAT_LIB (but not PETSC_KSP_LIB which does depend on PETSC_DM_LIB). Jed

1 0

Re: who broke PCFieldSplit code in petsc-dev?????????
by Satish Balay 11 Nov '09

11 Nov '09

On Wed, 11 Nov 2009, Barry Smith wrote: > If we were smart we would keep the results of each nights nightly builds and > then we could easily check what DAY things broke. Satish please have it save > the old days stuff for each day. Ok - I've changed the crontab to move the logfiles into http://ftp.mcs.anl.gov/pub/petsc/nightlylogs/archive/DATE Here date should be in the form 2009-Nov-11 Satish

1 0

Re: -malign-double
by Satish Balay 11 Nov '09

11 Nov '09

added to petsc-dev [buildSystem] satish On Wed, 11 Nov 2009, Barry Smith wrote: > > Satish, > > gcc supports the option -malign-double on some systems. Please add it to > the flags that configure checks for c and c++ and have it added if it exists. > > Thanks > > Barry >

1 0

-malign-double
by Barry Smith 11 Nov '09

11 Nov '09

Satish, gcc supports the option -malign-double on some systems. Please add it to the flags that configure checks for c and c++ and have it added if it exists. Thanks Barry

1 0