On Fri, Mar 1, 2013 at 3:26 AM, ?smund Ervik <asmund.ervik at ntnu.no> wrote:
> Thanks for clarifying this. I am already using OpenMP pragmas in non-PETSc > routines in my code, and using petsc-dev. Are you saying that I should also > somehow use OpenMP pragmas around the calls to KSPSolve etc.? > > Suppose that my program is usually run like this: > "./run -pc_type gamg -ksp_type bcgs" > with other values left to their defaults, and I want to make it run in > parallel: > "./run -pc type gamg -ksp_type bcgs -threadcomm_type openmp > -threadcomm_nthreads 8" > > When I do this, the PC and KSP still run in serial as far as I can tell, > and the program does not execute faster. What am I missing here? > Matrix and vector operations are probably running in parallel, but probably not the operations that are taking time. Always send -log_summary if you have a performance question. > In case it is of interest, the matrix from my Poisson equation has in the > range of 0.4 - 1 million nonzero elements, on average 5 per row. > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-dev/attachments/20130301/795d346f/attachment.html>
