diff options
Diffstat (limited to 'gnu/packages/patches/openmpi-psm2-priority.patch')
| -rw-r--r-- | gnu/packages/patches/openmpi-psm2-priority.patch | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/gnu/packages/patches/openmpi-psm2-priority.patch b/gnu/packages/patches/openmpi-psm2-priority.patch new file mode 100644 index 0000000000..d9dd558010 --- /dev/null +++ b/gnu/packages/patches/openmpi-psm2-priority.patch @@ -0,0 +1,21 @@ +PSM2 is the only valid implementation for OmniPath (OPA). UCX also +supports OmniPath, but it does so via Verbs, thus getting much lower +performance (typically 3 GiB/s instead of 10 GiB/s). + +To work around that, give the mtl_psm2 component a higher priority +than the pml_ucx component. + +See <https://www.mail-archive.com/users@lists.open-mpi.org/msg33581.html>. + +--- openmpi-4.0.2/ompi/mca/mtl/psm2/mtl_psm2_component.c 2019-11-15 17:06:15.142076840 +0100 ++++ openmpi-4.0.2/ompi/mca/mtl/psm2/mtl_psm2_component.c 2019-11-15 17:06:22.242009379 +0100 +@@ -126,7 +126,7 @@ ompi_mtl_psm2_component_register(void) + setenv("PSM2_DEVICES", "self,shm", 0); + } + +- param_priority = 40; ++ param_priority = 55; + (void) mca_base_component_var_register (&mca_mtl_psm2_component.super.mtl_version, + "priority", "Priority of the PSM2 MTL component", + MCA_BASE_VAR_TYPE_INT, NULL, 0, 0, + |