--- old/src/hotspot/cpu/sparc/templateInterpreterGenerator_sparc.cpp	2018-09-26 10:01:21.309640941 -0400
+++ new/src/hotspot/cpu/sparc/templateInterpreterGenerator_sparc.cpp	2018-09-26 10:01:19.749550161 -0400
@@ -1373,17 +1373,16 @@
     //     didn't see any synchronization is progress, and escapes.
     __ set(_thread_in_native_trans, G3_scratch);
     __ st(G3_scratch, thread_state);
-    if (os::is_MP()) {
-      if (UseMembar) {
-        // Force this write out before the read below
-        __ membar(Assembler::StoreLoad);
-      } else {
-        // Write serialization page so VM thread can do a pseudo remote membar.
-        // We use the current thread pointer to calculate a thread specific
-        // offset to write to within the page. This minimizes bus traffic
-        // due to cache line collision.
-        __ serialize_memory(G2_thread, G1_scratch, G3_scratch);
-      }
+
+    if (UseMembar) {
+      // Force this write out before the read below
+      __ membar(Assembler::StoreLoad);
+    } else {
+      // Write serialization page so VM thread can do a pseudo remote membar.
+      // We use the current thread pointer to calculate a thread specific
+      // offset to write to within the page. This minimizes bus traffic
+      // due to cache line collision.
+      __ serialize_memory(G2_thread, G1_scratch, G3_scratch);
     }
 
     Label L;