improve message to user when dat_ia_open fails

This commit was SVN r15362.

ompi/mca/btl/udapl/btl_udapl.c

@@ -151,8 +151,10 @@ mca_btl_udapl_init(DAT_NAME_PTR ia_name, mca_btl_udapl_module_t* btl)
 
         dat_strerror(rc, (const char**)&major,
             (const char**)&minor);
-        BTL_ERROR(("ERROR: %s %s %s\n", "dat_ia_open",
-            major, minor));
+
+        opal_show_help("help-mpi-btl-udapl.txt",
+            "dat_ia_open fail", true, ia_name, major, minor);
+
         return OMPI_ERROR;
     }
 

ompi/mca/btl/udapl/help-mpi-btl-udapl.txt

@@ -87,3 +87,11 @@ program fails.
 WARNING: The uDAPL BTL is not able to register memory. Possibly out of
 allowed privileged memory (i.e. memory that can be pinned). Increasing
 the allowed privileged memory may alleviate this issue.
+
+[dat_ia_open fail]
+
+WARNING: Failed to open "%s" [%s:%s]. 
+This may be a real error or it may be an invalid entry in the uDAPL
+Registry which is contained in the dat.conf file. Contact your local
+System Administrator to confirm the availability of the interfaces in
+the dat.conf file.