--- old/src/hotspot/share/runtime/perfMemory.cpp	2017-10-18 15:28:31.247537211 +0900
+++ new/src/hotspot/share/runtime/perfMemory.cpp	2017-10-18 15:28:31.070533674 +0900
@@ -53,6 +53,7 @@
 size_t                   PerfMemory::_capacity = 0;
 jint                     PerfMemory::_initialized = false;
 PerfDataPrologue*        PerfMemory::_prologue = NULL;
+bool                     PerfMemory::_destroyed = false;
 
 void perfMemory_init() {
 
@@ -64,7 +65,7 @@
 void perfMemory_exit() {
 
   if (!UsePerfData) return;
-  if (!PerfMemory::is_initialized()) return;
+  if (!PerfMemory::is_useable()) return;
 
   // Only destroy PerfData objects if we're at a safepoint and the
   // StatSampler is not active. Otherwise, we risk removing PerfData
@@ -160,7 +161,7 @@
 
 void PerfMemory::destroy() {
 
-  if (_prologue == NULL) return;
+  if (!is_useable()) return;
 
   if (_start != NULL && _prologue->overflow != 0) {
 
@@ -196,11 +197,7 @@
     delete_memory_region();
   }
 
-  _start = NULL;
-  _end = NULL;
-  _top = NULL;
-  _prologue = NULL;
-  _capacity = 0;
+  _destroyed = true;
 }
 
 // allocate an aligned block of memory from the PerfData memory
@@ -213,7 +210,7 @@
 
   MutexLocker ml(PerfDataMemAlloc_lock);
 
-  assert(_prologue != NULL, "called before initialization");
+  assert(is_useable(), "called before initialization");
 
   // check that there is enough memory for this request
   if ((_top + size) >= _end) {