Provide an MCA param to control hwloc shmem sharing

There are times when it can be beneficial to separate
the hwloc topology memory images between PRRTE and
applications it might be running. Provide an MCA param
to indicate that the topology should not be shared via
shmem. Default it to true (i.e., the topology shall be
shared in memory).

Signed-off-by: Ralph Castain <[email protected]>

Author: rhc54

src/prted/pmix/pmix_server.c

@@ -386,6 +386,8 @@ static void modex_resp(pmix_status_t status, char *data, size_t sz, void *cbdata
 static bool remote_connections_specified = false;
 static char *remote_cncts = NULL;
 static char *generate_dist = "fabric,gpu,network";
+static bool share_hwloc_memory = true;
+
 void pmix_server_register_params(void)
 {
     int i;
@@ -498,6 +500,10 @@ void pmix_server_register_params(void)
                                       PMIX_MCA_BASE_VAR_TYPE_BOOL,
                                       &prte_pmix_server_globals.system_controller);
 
+    (void) pmix_mca_base_var_register("prte", "pmix", NULL, "hwloc_shared_memory",
+                                      "Whether or not to share HWLOC topology via shared memory",
+                                      PMIX_MCA_BASE_VAR_TYPE_BOOL,
+                                      &share_hwloc_memory);
 }
 
 static void timeout_cbfunc(int sd, short args, void *cbdata)
@@ -709,7 +715,8 @@ int pmix_server_init(void)
         return rc;
     }
     // tell the server to share this topology for us
-    PMIX_INFO_LIST_ADD(prc, ilist, PMIX_SERVER_SHARE_TOPOLOGY, NULL, PMIX_BOOL);
+    PMIX_INFO_LIST_ADD(prc, ilist, PMIX_SERVER_SHARE_TOPOLOGY,
+                       (void*)&share_hwloc_memory, PMIX_BOOL);
     if (PMIX_SUCCESS != prc) {
         PMIX_INFO_LIST_RELEASE(ilist);
         rc = prte_pmix_convert_status(prc);