>>> Thanks for the information; the OpenMPI recommendation is probably because >>> OpenMPI goes to great lengths trying to avoid process migration. The >>> numactl doesn't prevent migration as far as I can tell: it controls where >>> memory gets allocated if it's NUMA. >> My understanding is that processes get pinned to cores with the help of >> the --physcpubind switch to numactl, but please correct me if I am wrong. >> > > The documentation isn't clear on that: you bind a process to a set of cores, > but that wouldn't necessarily mean that threads that belong to that process > are bound to a specific core. They might be allowed to migrate within the set > that you give the process.
I've just checked a short (a few seconds) benchmark run -- I didn't observe any migrations with or without numactl. A. -- Ansgar Esztermann DV-Systemadministration Max-Planck-Institut für biophysikalische Chemie, Abteilung 105 -- gmx-users mailing list gmx-users@gromacs.org http://lists.gromacs.org/mailman/listinfo/gmx-users Please search the archive at http://www.gromacs.org/Support/Mailing_Lists/Search before posting! Please don't post (un)subscribe requests to the list. Use the www interface or send it to gmx-users-requ...@gromacs.org. Can't post? Read http://www.gromacs.org/Support/Mailing_Lists
