From b57d60648340d110dd0246bb284263f17534c060 Mon Sep 17 00:00:00 2001
From: Jayesh Krishna <jayesh@mcs.anl.gov>
Date: Mon, 22 Apr 2019 12:36:54 -0400
Subject: [PATCH] Setting summit env for OOM errors

OLCF recommends setting "OMPI_MCA_io" env variable to "romio314"
to prevent out of memory issues with the code. In our testing we
have found that setting this env gets rid of OOM errors with
certain E3SM simulations (ECP simulation runs).

However also note that setting this environment variable reduces
the performance of parallel HDF5 (when using NetCDF4P PIO iotype
to write data).

See Issue #2856
---
 cime/config/e3sm/machines/config_machines.xml | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/cime/config/e3sm/machines/config_machines.xml b/cime/config/e3sm/machines/config_machines.xml
index 3efd70413ebc..df8724c5ad1b 100644
--- a/cime/config/e3sm/machines/config_machines.xml
+++ b/cime/config/e3sm/machines/config_machines.xml
@@ -3078,6 +3078,8 @@
     </environment_variables>
     <environment_variables mpilib="!mpi-serial">
       <env name="HDF5_PATH">$ENV{OLCF_HDF5_ROOT}</env>
+      <!-- OMPI_MCA_io env is required due to OOM errors -->
+      <env name="OMPI_MCA_io">romio314</env>
       <env name="PNETCDF_PATH">$ENV{OLCF_PARALLEL_NETCDF_ROOT}</env>
     </environment_variables>
   </machine>