On 2020-05-23 20:27, Junchao Zhang wrote:
On Sat, May 23, 2020 at 1:49 AM Drew Parsons <dpars...@debian.org>
wrote:
On 2020-05-23 14:18, Jed Brown wrote:
You don't need to change BLAS or MPI.
I see, the PETSc API allows for PetscBLASInt and PetscMPIInt
distinct
from PetscInt. That gives us more flexibility. (In any case, the
Debian
BLAS maintainer is already providing blas64 packages. We've started
discussions about MPI).
But what about MUMPS? Would MUMPS need to be built with 64 bit
support
to work with 64-bit PETSc?
(the MUMPS docs indicate that its 64 bit support needs 64-bit
versions
of BLAS, SCOTCH, METIS and MPI).
In MUMPS's manual, it is called full 64-bit. Out of the same memory
bandwidth concern, MUMPS also supports selective 64-bit, in a sense it
only uses int64_t for selected variables. One can still use it with
32-bit BLAS, MPI etc. We support selective 64-bit MUMPS starting from
petsc-3.13.0
Thanks Junchao. Sounds like we can get started on providing 64-bit
MUMPS and PETSc without needing to wait for MPI then.
That's good timing with 3.13.
Drew
