This commit adds a help message when system limitations prevent setting up OSHMEM's symmetric heap. This fixes trac:4399 and should be added to

cmr=v1.7.5:reviewer=jsquyres

This commit was SVN r31172.

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

oshmem/mca/memheap/base/help-shmem-mca.txt

@@ -21,3 +21,13 @@ output of the "ompi_info" command and ensure that components of this
 type are available on your system.  You may also wish to check the
 value of the "component_path" MCA parameter and ensure that it has at
 least one directory that contains valid MCA components.
+
+[sysv:create-segment-failture]
+'sshmem' 'sysv' was failed to allocate shared memory segment
+of requested size. Returned error corresponds to
+invalid agrument function call which most likely
+is size of shared segment to allocate.
+
+Try using other 'sshmem' components (e.g. 'mmap')
+with '-mca sshmem mmap' or decrease symmetric heap area size
+with '-x SHMEM_SYMMETRIC_HEAP_SIZE=<value>'.

oshmem/mca/sshmem/sysv/sshmem_sysv_module.c

@@ -44,6 +44,7 @@
 #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"
@@ -192,10 +193,15 @@ segment_create(map_segment_t *ds_buf,
     shmid = shmget(IPC_PRIVATE, size, flags);
     if (shmid == MAP_SEGMENT_SHM_INVALID) {
         OPAL_OUTPUT_VERBOSE(
-           (5, oshmem_sshmem_base_framework.framework_output,
-           "Failed to shmget() %llu bytes (errno=%d)",
-                      (unsigned long long)size, errno)
-            );
+            (5, oshmem_sshmem_base_framework.framework_output,
+             "Failed to shmget() %llu bytes (errno=%d)",
+             (unsigned long long)size, errno));
+
+        if (EINVAL == errno) {
+            orte_show_help("help-shmem-mca.txt",
+                           "sysv:create-segment-failture",
+                           true);
+        }
         return OSHMEM_ERROR;
     }