--- a/src/hotspot/share/jfr/recorder/checkpoint/jfrCheckpointManager.cpp	Sun Aug 25 13:27:54 2019 +0200
+++ b/src/hotspot/share/jfr/recorder/checkpoint/jfrCheckpointManager.cpp	Sun Aug 25 15:13:16 2019 +0200
@@ -407,6 +407,10 @@
   JfrTypeManager::write_type_set_for_unloaded_classes();
 }
 
+bool JfrCheckpointManager::is_type_set_checkpoint_required() const {
+  return JfrTraceIdEpoch::is_klass_tagged_in_epoch();
+}
+
 size_t JfrCheckpointManager::flush_type_set() {
   const size_t elements = JfrTypeManager::flush_type_set();
   flush();

--- a/src/hotspot/share/jfr/recorder/checkpoint/jfrCheckpointManager.hpp	Sun Aug 25 13:27:54 2019 +0200
+++ b/src/hotspot/share/jfr/recorder/checkpoint/jfrCheckpointManager.hpp	Sun Aug 25 15:13:16 2019 +0200
@@ -95,6 +95,7 @@
 
  public:
   void register_service_thread(const Thread* t);
+  bool is_type_set_checkpoint_required() const;
   size_t flush_type_set();
   static void write_type_set_for_unloaded_classes();
   static void create_thread_checkpoint(Thread* t);

--- a/src/hotspot/share/jfr/recorder/checkpoint/types/traceid/jfrTraceId.inline.hpp	Sun Aug 25 13:27:54 2019 +0200
+++ b/src/hotspot/share/jfr/recorder/checkpoint/types/traceid/jfrTraceId.inline.hpp	Sun Aug 25 15:13:16 2019 +0200
@@ -28,8 +28,9 @@
 #include "classfile/classLoaderData.hpp"
 #include "classfile/moduleEntry.hpp"
 #include "classfile/packageEntry.hpp"
+#include "jfr/recorder/checkpoint/types/traceid/jfrTraceId.hpp"
+#include "jfr/recorder/checkpoint/types/traceid/jfrTraceIdEpoch.hpp"
 #include "jfr/recorder/checkpoint/types/traceid/jfrTraceIdMacros.hpp"
-#include "jfr/recorder/checkpoint/types/traceid/jfrTraceId.hpp"
 #include "oops/arrayKlass.hpp"
 #include "oops/klass.hpp"
 #include "oops/instanceKlass.hpp"
@@ -57,7 +58,11 @@
 
 inline traceid JfrTraceId::use(const Klass* klass) {
   assert(klass != NULL, "invariant");
-  return set_used_and_get(klass);
+  const traceid id = set_used_and_get(klass);
+  if (IS_NOT_SERIALIZED(klass)) {
+    JfrTraceIdEpoch::set_klass_tagged_in_epoch();
+  }
+  return id;
 }
 
 inline traceid JfrTraceId::use(const Method* method) {
@@ -71,6 +76,9 @@
   SET_METHOD_FLAG_USED_THIS_EPOCH(method);
   SET_METHOD_AND_CLASS_USED_THIS_EPOCH(klass);
   assert(METHOD_AND_CLASS_USED_THIS_EPOCH(klass), "invariant");
+  if (IS_NOT_SERIALIZED(klass)) {
+    JfrTraceIdEpoch::set_klass_tagged_in_epoch();
+  }
   return (METHOD_ID(klass, method));
 }
 

--- a/src/hotspot/share/jfr/recorder/checkpoint/types/traceid/jfrTraceIdEpoch.cpp	Sun Aug 25 13:27:54 2019 +0200
+++ b/src/hotspot/share/jfr/recorder/checkpoint/types/traceid/jfrTraceIdEpoch.cpp	Sun Aug 25 15:13:16 2019 +0200
@@ -31,6 +31,8 @@
 // The regular epoch shift happens only during a safepoint.
 // The fence is there only for the emergency dump case which happens outside of safepoint.
 bool JfrTraceIdEpoch::_epoch_state = false;
+bool volatile JfrTraceIdEpoch::_klass_tagged_in_epoch = false;
+
 void JfrTraceIdEpoch::shift_epoch() {
   _epoch_state = !_epoch_state;
   if (!SafepointSynchronize::is_at_safepoint()) {

--- a/src/hotspot/share/jfr/recorder/checkpoint/types/traceid/jfrTraceIdEpoch.hpp	Sun Aug 25 13:27:54 2019 +0200
+++ b/src/hotspot/share/jfr/recorder/checkpoint/types/traceid/jfrTraceIdEpoch.hpp	Sun Aug 25 15:13:16 2019 +0200
@@ -26,7 +26,7 @@
 #define SHARE_JFR_RECORDER_CHECKPOINT_TYPES_TRACEID_JFRTRACEIDEPOCH_HPP
 
 #include "memory/allocation.hpp"
-#include "jfr/utilities/jfrTypes.hpp"
+#include "runtime/orderAccess.hpp"
 
 #define USED_BIT 1
 #define METHOD_USED_BIT (USED_BIT << 2)
@@ -44,6 +44,8 @@
   friend class JfrCheckpointManager;
  private:
   static bool _epoch_state;
+  static bool volatile _klass_tagged_in_epoch;
+
   static void shift_epoch();
 
  public:
@@ -86,6 +88,20 @@
   static traceid method_and_class_in_use_prev_epoch_bits() {
     return _epoch_state ? METHOD_AND_CLASS_IN_USE_EPOCH_1_BITS :  METHOD_AND_CLASS_IN_USE_EPOCH_2_BITS;
   }
+
+  static bool is_klass_tagged_in_epoch() {
+    if (OrderAccess::load_acquire(&_klass_tagged_in_epoch)) {
+      OrderAccess::release_store(&_klass_tagged_in_epoch, false);
+      return true;
+    }
+    return false;
+  }
+
+  static void set_klass_tagged_in_epoch() {
+    if (!OrderAccess::load_acquire(&_klass_tagged_in_epoch)) {
+      OrderAccess::release_store(&_klass_tagged_in_epoch, true);
+    }
+  }
 };
 
 #endif // SHARE_JFR_RECORDER_CHECKPOINT_TYPES_TRACEID_JFRTRACEIDEPOCH_HPP

--- a/src/hotspot/share/jfr/recorder/service/jfrRecorderService.cpp	Sun Aug 25 13:27:54 2019 +0200
+++ b/src/hotspot/share/jfr/recorder/service/jfrRecorderService.cpp	Sun Aug 25 15:13:16 2019 +0200
@@ -614,7 +614,9 @@
   if (_string_pool.is_modified()) {
     total_elements += flush_stringpool(_string_pool, _chunkwriter);
   }
-  total_elements += flush_typeset(_checkpoint_manager, _chunkwriter);
+  if (_checkpoint_manager.is_type_set_checkpoint_required()) {
+    total_elements += flush_typeset(_checkpoint_manager, _chunkwriter);
+  }
   return total_elements;
 }