- Add comment for volatile.

This commit was SVN r12436.

test/memory/opal_memory_basic.c

@@ -27,6 +27,10 @@
 #include "opal/runtime/opal.h"
 #include "opal/memoryhooks/memory.h"
 
+/* 
+ * The counter variable is volatile to avoid (wrong) compiler optimisations, 
+ * which can lead to wrong code.
+ */
 volatile int counter = 0;
 const int bigsize = 100 * 1024 * 1024;