--- old/src/hotspot/share/gc/shared/threadLocalAllocBuffer.hpp	2018-03-08 15:53:23.843614606 -0800
+++ new/src/hotspot/share/gc/shared/threadLocalAllocBuffer.hpp	2018-03-08 15:53:23.587615472 -0800
@@ -38,12 +38,11 @@
 //            time across multiple threads. The park()/unpark() pair is
 //            used to make it available for such multiplexing.
 //
-//            Heap sampling is performed via the end/actual_end fields.
-//            actual_end contains the real end of the tlab allocation,
-//            whereas end can be set to an arbitrary spot in the tlab to
+//            Heap sampling is performed via the current_end/allocation_end
+//            fields.
+//            allocation_end contains the real end of the tlab allocation,
+//            whereas current_end can be set to an arbitrary spot in the tlab to
 //            trip the return and sample the allocation.
-//            slow_path_end is used to track if a fast tlab refill occured
-//            between slowpath calls.
 class ThreadLocalAllocBuffer: public CHeapObj<mtThread> {
   friend class VMStructs;
   friend class JVMCIVMStructs;
@@ -53,7 +52,6 @@
   HeapWord* _pf_top;                             // allocation prefetch watermark
   HeapWord* _current_end;                        // allocation end (can be the sampling end point or _allocation_end)
   HeapWord* _allocation_end;                     // end for allocations (actual TLAB end, excluding alignment_reserve)
-  HeapWord* _last_slow_path_end;                 // last address for slow_path_end (as opposed to _allocation_end)
 
   size_t    _desired_size;                       // desired size   (including alignment_reserve)
   size_t    _refill_waste_limit;                 // hold onto tlab if free() is larger than this
@@ -78,7 +76,6 @@
   void set_start(HeapWord* start)                { _start = start; }
   void set_current_end(HeapWord* current_end)    { _current_end = current_end; }
   void set_allocation_end(HeapWord* ptr)         { _allocation_end = ptr; }
-  void set_last_slow_path_end(HeapWord* ptr)     { _last_slow_path_end = ptr; }
   void set_top(HeapWord* top)                    { _top = top; }
   void set_pf_top(HeapWord* pf_top)              { _pf_top = pf_top; }
   void set_desired_size(size_t desired_size)     { _desired_size = desired_size; }