Isn't this a case for --map-by core --bind-to hwthread? Because you want to map each
process by core but bind the the first hwthread.From the looks of it your process is
both binding and mapping by hwthread now. -NathanOn Sep 11, 2023, at 10:20 AM, Luis
Cebamanos via users <users@lists.open-mpi.org> wrote:@Gilles @Jeff Sorry, I
think I replied too quickly. This is what I
see if using --bind-to hwthread <Z9k0wIPYngd30f0X.png> This is not what I
was after. I only want to use thread 0 of a core
ie (cores 0-7), so "cores 192-199" should not have any activity. If
I do --bind-to core, the activity jumps from "core 0" to "core 192",
and I want to avoid that. Any other suggestion? Regards L On 08/09/2023
17:53, Jeff Squyres
(jsquyres) wrote:In addition to what Gilles mentioned, I'm curious: is
there a
reason you have hardware threads enabled? You could disable
them in the BIOS, and then each of your MPI processes can use
the full core, not just a single hardware thread.From: users
<users-boun...@lists.open-mpi.org> on behalf of Luis
Cebamanos via users <users@lists.open-mpi.org> Sent: Friday, September 8, 2023
7:10 AM To: Ralph Castain via users <users@lists.open-mpi.org> Cc: Luis Cebamanos
<luic...@gmail.com> Subject: [OMPI users] Binding to thread 0 Hello,Up to now, I have been
using numerous ways of binding
with wrappers (numactl, taskset) whenever I wanted to play
with core placing. Another way I have been using is via
-rankfile, however I notice that some ranks jump from thread
0 to thread 1 on SMT chips. I can control this with numactl
for instance, but it would be great to see similar behaviour
when using -rankfile. Is there a way to pack all ranks to
one of the threads of each core (preferibly to thread 0) so
I can nicely see all ranks with htop on either left or right
of the screen?The command I am using is pretty simple:mpirun -np
$MPIRANKS --rankfile ./myrankfile and ./myrankfile looks likerank 33=argon
slot=33 rank 34=argon slot=34 rank 35=argon slot=35 rank 36=argon slot=36Thanks!
