OSHMEM: better error handling for sshmem/mmap

Refs trac:4399

fixed by Roman, reviewed by Miked

cmr=v1.7.5:reviewer=ompi-rm1.7

This commit was SVN r31179.

The following Trac tickets were found above:
  Ticket 4399 --> https://svn.open-mpi.org/trac/ompi/ticket/4399

oshmem/mca/sshmem/mmap/Makefile.am

@@ -7,6 +7,8 @@
 # $HEADER$
 #
 
+dist_ompidata_DATA = help-oshmem-sshmem-mmap.txt
+
 sources = \
         sshmem_mmap.h \
         sshmem_mmap_component.c \

oshmem/mca/sshmem/mmap/help-oshmem-sshmem-mmap.txt

@@ -0,0 +1,20 @@
+# -*- text -*- 
+#
+# Copyright (c) 2014      Mellanox Technologies, Inc.
+#                         All rights reserved.
+# $COPYRIGHT$
+# 
+# Additional copyrights may follow
+# 
+# $HEADER$
+#
+# This is the US/English help file for Open SHMEM MCA error messages.
+#
+
+[mmap:out-of-memory]
+'sshmem' 'mmap' was failed to allocate shared memory segment
+of requested size. Returned error corresponds to
+out of memory case.
+
+Try decreasing symmetric heap area size with
+'-x SHMEM_SYMMETRIC_HEAP_SIZE=<value>'.

oshmem/mca/sshmem/mmap/sshmem_mmap_module.c

@@ -40,6 +40,7 @@
 #include "opal/util/output.h"
 #include "opal/util/path.h"
 #include "opal/util/show_help.h"
+#include "orte/util/show_help.h"
 
 #include "oshmem/mca/sshmem/sshmem.h"
 #include "oshmem/mca/sshmem/base/base.h"
@@ -197,6 +198,11 @@ segment_create(map_segment_t *ds_buf,
            "Failed to mmap() %llu bytes (errno=%d)",
                       (unsigned long long)size, errno)
             );
+        if (ENOMEM == errno) {
+            orte_show_help("help-oshmem-sshmem-mmap.txt",
+                           "mmap:out-of-memory",
+                           true);
+        }
         return OSHMEM_ERR_OUT_OF_RESOURCE;
     }