Hi Barry, On 28. feb. 2013 17:38, Barry Smith wrote: > > 2) You should not need petscthreadcomm.h in Fortran. Simply using OpenMP > progmas in your portion of the code. >
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? 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. Regards, ?smund