diff -r db65921e9a9b -r bd6b78feb6a3 src/hotspot/share/gc/shared/strongRootsScope.cpp
--- a/src/hotspot/share/gc/shared/strongRootsScope.cpp	Thu Jun 07 06:27:09 2018 -0400
+++ b/src/hotspot/share/gc/shared/strongRootsScope.cpp	Thu Jun 07 14:11:56 2018 +0200
@@ -38,8 +38,6 @@
 
 StrongRootsScope::StrongRootsScope(uint n_threads) : _n_threads(n_threads) {
   Threads::change_thread_claim_parity();
-  // Zero the claimed high water mark in the StringTable
-  StringTable::clear_parallel_claimed_index();
 }
 
 StrongRootsScope::~StrongRootsScope() {