Re: [OMPI users] How it the rank determined (Open MPI and Podman)

2019-07-12 Thread Adrian Reber via users
So upstream Podman was really fast and merged a PR which makes my wrapper unnecessary: Add support for --env-host : https://github.com/containers/libpod/pull/3557 As commented in the PR I can now start mpirun with Podman without a wrapper: $ mpirun --hostfile ~/hosts --mca orte_tmpdir_base

Re: [OMPI users] How it the rank determined (Open MPI and Podman)

2019-07-12 Thread Gilles Gouaillardet via users
Adrian, Can you try mpirun --mca btl_vader_copy_mechanism none ... Please double check the MCA parameter name, I am AFK IIRC, the default copy mechanism used by vader directly accesses the remote process address space, and this requires some permission (ptrace?) that might be dropped by

Re: [OMPI users] How it the rank determined (Open MPI and Podman)

2019-07-12 Thread Adrian Reber via users
Gilles, thanks again. Adding '--mca btl_vader_single_copy_mechanism none' helps indeed. The default seems to be 'cma' and that seems to use process_vm_readv() and process_vm_writev(). That seems to require CAP_SYS_PTRACE, but telling Podman to give the process CAP_SYS_PTRACE with