> I hear PETSc has some magic flag that lets it run multithreaded but I > don't know how to turn that on.
Below is Matt's answer to my question. I guess I misunderstoof back then how this is going to work, it isn't quite what I had in mind... The link to the function he mentions is this: http://www-unix.mcs.anl.gov/petsc/petsc-as/snapshots/petsc-current/docs/manualpages/PC/PCOPENMP.html W. -------------------------------- Date: Fri, 25 Jan 2008 12:06:54 -0600 From: Matthew Knepley To: Wolfgang Bangerth Subject: Re: Multithreading in PETSc It took me a while to parse this. We do not support threads per se, but we have a preconditioner called OPENMP. It is a true Barryism since there is only MPI in it :) It is for serial jobs. Basically, it starts up a large communicator but only uses the first process for normal PETSc work. When you get to the solver, it brings in all the other MPI processes, which in a good implementation are threads. There are examples in the development documentation on the web if you go to PC/OPENMP. Warning: you need a simply ridiculous number of command line options to drive it, but it shows great speedup. The guy at Harvard loves it. Matt On Jan 25, 2008 11:16 AM, Wolfgang Bangerth <[EMAIL PROTECTED]> wrote: > > Hi Matt, > back in Boulder you said that there is a flag that makes PETSc internally > use threads to speed up things. This topic has come up again in a > discussion, and it reminded me that I wanted to ask you about the secret > way to enable this feature. Is there a short answer? > > Best > Wolfgang > > ------------------------------------------------------------------------- > Wolfgang Bangerth email: [EMAIL PROTECTED] > www: http://www.math.tamu.edu/~bangerth/ > > ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ Libmesh-users mailing list Libmesh-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libmesh-users
