Add minimal support (#processors only) for OSX and other systems that don't have paffinity modules.

This commit was SVN r18959.

opal/mca/paffinity/base/paffinity_base_wrappers.c

@@ -21,6 +21,10 @@
 
 #include "opal_config.h"
 
+#if HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+
 #include "opal/constants.h"
 #include "opal/mca/paffinity/paffinity.h"
 #include "opal/mca/paffinity/base/base.h"
@@ -66,8 +70,27 @@ int opal_paffinity_base_map_to_socket_core(int processor_id, int *socket, int *c
 
 int opal_paffinity_base_get_processor_info(int *num_processors, int *max_processor_id)
 {
+    int rc;
+    
     if (!opal_paffinity_base_selected) {
-        return OPAL_ERR_NOT_FOUND;
+        /* since no module was available, we do the best we can
+         * with a POSIX-standard query
+         */
+        if (0 > (rc = sysconf(_SC_NPROCESSORS_ONLN))) {
+            /* system was unable to provide a number, so return
+             * an error and set the values to something negative
+             */
+            *num_processors = *max_processor_id = -1;
+            return OPAL_ERR_NOT_FOUND;
+        }
+        /* rc will contain a guess at the number of processors
+         * that are currently online - return that value
+         */
+        *num_processors = *max_processor_id = rc;
+        /* since we found something and it is the best we can do,
+         * return success
+         */
+        return OPAL_SUCCESS;
     }
     return opal_paffinity_base_module->paff_get_processor_info(num_processors, max_processor_id);
 }