--- old/src/os/aix/vm/os_aix.cpp	Thu Jun 21 18:15:17 2018
+++ new/src/os/aix/vm/os_aix.cpp	Thu Jun 21 18:15:16 2018
@@ -4008,6 +4008,16 @@
 };
 
 int os::active_processor_count() {
+  // User has overridden the number of active processors
+  if (ActiveProcessorCount > 0) {
+    if (PrintActiveCpus) {
+      tty->print_cr("active_processor_count: "
+                    "active processor count set by user : %d",
+                     ActiveProcessorCount);
+    } 
+    return ActiveProcessorCount;
+  }
+
   int online_cpus = ::sysconf(_SC_NPROCESSORS_ONLN);
   assert(online_cpus > 0 && online_cpus <= processor_count(), "sanity check");
   return online_cpus;