--- a/src/hotspot/share/gc/z/zDriver.cpp	Tue Aug 06 09:27:38 2019 -0400
+++ b/src/hotspot/share/gc/z/zDriver.cpp	Tue Aug 06 15:49:53 2019 +0200
@@ -87,8 +87,8 @@
     GCIdMark gc_id_mark(_gc_id);
     IsGCActiveMark gc_active_mark;
 
-    // Verify roots
-    ZVerify::roots_strong();
+    // Verify before operation
+    ZVerify::before_zoperation();
 
     // Execute operation
     _success = do_operation();

--- a/src/hotspot/share/gc/z/zVerify.cpp	Tue Aug 06 09:27:38 2019 -0400
+++ b/src/hotspot/share/gc/z/zVerify.cpp	Tue Aug 06 15:49:53 2019 +0200
@@ -143,6 +143,12 @@
   objects(verify_weaks);
 }
 
+void ZVerify::before_zoperation() {
+  // Verify strong roots
+  ZStatTimerDisable disable;
+  roots_strong();
+}
+
 void ZVerify::after_mark() {
   // Only verify strong roots and references.
   roots_and_objects(false /* verify_weaks */);

--- a/src/hotspot/share/gc/z/zVerify.hpp	Tue Aug 06 09:27:38 2019 -0400
+++ b/src/hotspot/share/gc/z/zVerify.hpp	Tue Aug 06 15:49:53 2019 +0200
@@ -32,6 +32,7 @@
   static void roots_impl();
   static void roots(bool verify_weaks);
 
+  static void roots_strong();
   static void roots_weak();
   static void roots_concurrent();
   static void roots_concurrent_weak();
@@ -42,7 +43,7 @@
 
 public:
   // Verify strong (non-concurrent) roots. Should always be good.
-  static void roots_strong();
+  static void before_zoperation();
 
   // Verify all strong roots and references after marking.
   static void after_mark();