Make an issue
> On Jul 30, 2019, at 7:00 PM, Jed Brown <[email protected]> wrote: > > "Smith, Barry F. via petsc-users" <[email protected]> writes: > >> The reason this worked for 4 processes is that the largest count in that >> case was roughly 6,653,750,976/4 which does fit into an int. PETSc only >> needs to know the number of nonzeros on each process, it doesn't need to >> know the amount across all the processors. In other words you may want to >> use a different PETSC_ARCH (different configuration) for small number of >> processors and large number depending on how large your problem is. Or you >> can always use 64 bit integers at a little performance and memory cost. > > We could consider always using 64-bit ints for quantities like row > starts, keeping column indices (the "heavy" part) in 32-bit. This may > become a more frequent issue with fatter nodes and many GPUs potentially > being driven by a single MPI rank.
