Re: New prerequisites to support multi image COARRAY in gfortran
On 04/04/2017 10:44 AM, FX wrote: >> We choose mpich as a default only because it is very stable. > > Why are why tying ourselves to one MPI implementation? > > FX > Not tying ourselves at all. This just gives users who install gcc manually with the ./configure process a default to use and only if they are using the download prerequisites script which is optional. Distributions can still provide multiple choices with package managers. The final tie is at link time where a user may specify any compatible library they choose. We do have a base of users who do not use package managers by the way. So the goal is a minimal installation of a fully functional Fortran. Jerry
Re: New prerequisites to support multi image COARRAY in gfortran
On April 4, 2017 at 9:48:23 AM, Jerry DeLisle (jvdeli...@charter.net(mailto:jvdeli...@charter.net)) wrote: > Gerald, (or who does this) > > Since shared memory parallel programming with Fortran is now a Standard > feature > of the language, we would like to support full parallelism through the use of > > mpich and OpenCorrays. Clarification: Fortran’s parallel programming model is agnostic about the memory architecture. The 2008 standard made Fortran the only widely used language with a parallel programming model that works in shared- or distributed-memory systems. I’ve seen papers in which people have run coarray Fortran (CAF) on over 100,000 cores with impressive results. As a side note, the draft 2015 standard makes Fortran also the only widely used language with support for fault tolerance, which makes Alessandro’s and Andre’s work on failed-image support truly exciting and I’m amazed that there already exists an MPI limitation with some support for what is needed to support failed-image detection. Damian
Re: New prerequisites to support multi image COARRAY in gfortran
Resending as plain text (although now I realize my reply is at least partially redundant since reading Andre’s email): On April 4, 2017 at 10:44:09 AM, FX (fxcoud...@gmail.com(mailto:fxcoud...@gmail.com)) wrote: > > We choose mpich as a default only because it is very stable. > > Why are why tying ourselves to one MPI implementation? > Jerry’s request is just to put an MPICH tar ball on the GCC ftp server as a default. When we modify “configure,” there will be a --with-mpi option that enables users to choose their own MPI implementation. Damian
Re: New prerequisites to support multi image COARRAY in gfortran
Hi FX, we don't really do. You can use other MPI implementation as well, albeit not all features are implemented in all the others. For failed images support we needed the fault tolerance support for MPI, which I see only in mpich from 3.2 on. The other MPI implementations publicy available do not support ft at the moment. So as soon as they do in their stable versions, we might give the user more choice. - Andre On Tue, 4 Apr 2017 19:44:06 +0200 FXwrote: > > We choose mpich as a default only because it is very stable. > > Why are why tying ourselves to one MPI implementation? > > FX -- Andre Vehreschild * Email: vehre ad gmx dot de
Re: New prerequisites to support multi image COARRAY in gfortran
> We choose mpich as a default only because it is very stable. Why are why tying ourselves to one MPI implementation? FX
New prerequisites to support multi image COARRAY in gfortran
Gerald, (or who does this) Since shared memory parallel programming with Fortran is now a Standard feature of the language, we would like to support full parallelism through the use of mpich and OpenCorrays. We choose mpich as a default only because it is very stable. We choose OpenCoarrays because it works well with gfortran and the developers have also supported significant portions of the gfortran frontend (not to mention that it is the only such library available). Choosing these as defaults for gfortran does not exclude any user from using any other libraries in the future since the final connection occurs at link time when a user compiles with -fcoarray=lib. In order to support testing of installation of the new packages we are requesting that the package tarballs be placed on the gcc.gnu.org along with the other gcc prerequisite packages here: ftp://gcc.gnu.org/pub/gcc/infrastructure/ There will be two stable released packages with appropriate shasum information to be added. I can provide the links to those packages for download or send them to you directly. Requesting approval for this first step. (Later steps (more than one) will provide patches for review of the contrib/download_prerequisites script. Another step will be modifying OpenCoarrays build structure to align with the Gnu/gcc build process. I believe mpich is already suitable, but will be testing.) Is this OK? Regards, Jerry