--- old/src/hotspot/share/runtime/globals.hpp	2018-11-19 17:22:46.762646100 -0800
+++ new/src/hotspot/share/runtime/globals.hpp	2018-11-19 17:22:45.886082000 -0800
@@ -2604,15 +2604,7 @@
           "Use platform unstable time where supported for timestamps only") \
                                                                             \
   experimental(ccstr, AllocateOldGenAt, NULL,                               \
-               "Directory to use for allocating old generation")            \
-                                                                            \
-  experimental(uintx, G1YoungExpansionBufferPerc, 10,                       \
-               "When heterogenous heap is enabled by AllocateOldGenAt "     \
-               "option, after every GC, yg gen is re-sized which involves " \
-               "system calls to commit/uncommit memory. To reduce these "   \
-               "calls, we keep a buffer of extra regions to absorb small "  \
-               "changes in yg gen length. This flag takes the buffer "      \
-               "size as an percentage of young gen length")
+               "Directory to use for allocating old generation")
 
 #define VM_FLAGS(develop,                                                   \
                  develop_pd,                                                \