From: Nichols A. Romero
Date: Tue, 20 Nov 2012 12:05:42 -0600 (CST)
Is PZHEEVD deterministic? By that I mean, if I fix the input matrix and run
PZHEEVD repeatedly on a fixed number of MPI tasks on the same architecture will
I get the same result to machine precision every time. Let's assume everything
is single-threaded, e.g. no threaded BLAS.
After some discussion, with a vendor (IBM) and the MPICH2 developers I am told
that collectives are deterministic.
After taking a closer look at PZHEEVD, the only non-deterministic behavior I
see is in the routine PZHETRD which uses BI_TreeComb which itself does not look
deterministic from the use of MPI_ANY_SOURCE (define to the variable BANYNODE).
Is there a deterministic version of BI_TreeComb available?
Nichols A. Romero, Ph.D.
Argonne Leadership Computing Facility
Argonne National Laboratory
Building 240 Room 2-127
9700 South Cass Avenue
Argonne, IL 60490