[petsc-users] Configuration of Hybrid MPI-OpenMP

[Karl Rupp]

Hi Danyang,

PETSc is supposed to work with the MPI-OpenMP hybridization just as you 
request it.

 > I tried to configure PETSc with both MPI and OpenMP enabled, but failed.

Please provide details on why it failed. Please send configure.log and 
make.log to petsc-maint.


> BTW: I have also tried to use "PETSc for WINDOWS2.0"
> (http://www.msic.ch/Software). Both the OpenMP instructions and PETSc
> solver (MPI) can work well, but the solver speedup is not as significant
> as compiling in CYGWIN with PETSc 3.4.3. Usually the speedup of solver
> is 1.5 times slower.

Note that due to the saturation of the memory links you have to be 
careful with what you define as 'speedup' and how you compare execution 
times. Also, thread affinities become pretty important if you are on a 
NUMA machine.

> Is it possible to configure PETSc with Hybrid MPI-OPenMP? How?

--with-threadcomm --with-openmp should suffice.

Best regards,
Karli