btl/ofi: Export memory monitor

The OFI MTL exports a memory monitor to Libfabric (so that OMPI's
patcher wins), but in cases where OB1 is directly selected, that
code won't run.  So make sure to also configure Libfabric so that
it won't try to use a suboptimial memory monitor in the case that
only the OFI BTL is used.

Signed-off-by: Brian Barrett <bbarrett@amazon.com>

Author: bwbarrett

opal/mca/btl/ofi/btl_ofi_module.c

@@ -148,6 +148,20 @@ void mca_btl_ofi_rcache_init(mca_btl_ofi_module_t *module)
     if (!module->initialized) {
         mca_rcache_base_resources_t rcache_resources;
         char *tmp;
+        int ret;
+
+        /* this must be called during single threaded part of the code and
+         * before Libfabric configures its memory monitors.  Easiest to do
+         * that before domain open.  Silently ignore not-supported errors,
+         * as they are not critical to program correctness, but only
+         * indicate that LIbfabric will have to pick a different, possibly
+         * less optimal, monitor. */
+        ret = opal_common_ofi_export_memory_monitor();
+        if (0 != ret && -FI_ENOSYS != ret) {
+            opal_output_verbose(1, opal_common_ofi.output,
+                                "Failed to inject Libfabric memory monitor: %s",
+                                fi_strerror(-ret));
+        }
 
         (void) opal_asprintf(&tmp, "ofi.%s", module->linux_device_name);