--- old/src/hotspot/share/gc/shared/ptrQueue.cpp	2019-11-21 11:55:07.532907849 +0100
+++ new/src/hotspot/share/gc/shared/ptrQueue.cpp	2019-11-21 11:55:07.276903521 +0100
@@ -197,7 +197,7 @@
 bool BufferNode::Allocator::try_transfer_pending() {
   // Attempt to claim the lock.
   if (Atomic::load(&_transfer_lock) || // Skip CAS if likely to fail.
-      Atomic::cmpxchg(true, &_transfer_lock, false)) {
+      Atomic::cmpxchg(&_transfer_lock, false, true)) {
     return false;
   }
   // Have the lock; perform the transfer.