--- old/src/hotspot/share/runtime/objectMonitor.cpp	2018-09-17 23:27:45.955749321 -0700
+++ new/src/hotspot/share/runtime/objectMonitor.cpp	2018-09-17 23:27:45.747749328 -0700
@@ -127,7 +127,6 @@
 static int Knob_ExitPolicy          = 0;
 static int Knob_PreSpin             = 10;      // 20-100 likely better
 static int Knob_ResetEvent          = 0;
-static int BackOffMask              = 0;
 
 static int Knob_FastHSSEC           = 0;
 static int Knob_MoveNotifyee        = 2;       // notify() - disposition of notifyee
@@ -1873,8 +1872,6 @@
   // CONSIDER: use Prefetch::write() to avoid RTS->RTO upgrades
   // when preparing to LD...CAS _owner, etc and the CAS is likely
   // to succeed.
-  int hits    = 0;
-  int msk     = 0;
   int caspty  = Knob_CASPenalty;
   int oxpty   = Knob_OXPenalty;
   int sss     = Knob_SpinSetSucc;
@@ -1906,29 +1903,6 @@
 
     if (Knob_UsePause & 2) SpinPause();
 
-    // Exponential back-off ...  Stay off the bus to reduce coherency traffic.
-    // This is useful on classic SMP systems, but is of less utility on
-    // N1-style CMT platforms.
-    //
-    // Trade-off: lock acquisition latency vs coherency bandwidth.
-    // Lock hold times are typically short.  A histogram
-    // of successful spin attempts shows that we usually acquire
-    // the lock early in the spin.  That suggests we want to
-    // sample _owner frequently in the early phase of the spin,
-    // but then back-off and sample less frequently as the spin
-    // progresses.  The back-off makes a good citizen on SMP big
-    // SMP systems.  Oversampling _owner can consume excessive
-    // coherency bandwidth.  Relatedly, if we _oversample _owner we
-    // can inadvertently interfere with the the ST m->owner=null.
-    // executed by the lock owner.
-    if (ctr & msk) continue;
-    ++hits;
-    if ((hits & 0xF) == 0) {
-      // The 0xF, above, corresponds to the exponent.
-      // Consider: (msk+1)|msk
-      msk = ((msk << 2)|3) & BackOffMask;
-    }
-
     // Probe _owner with TATAS
     // If this thread observes the monitor transition or flicker
     // from locked to unlocked to locked, then the odds that this
@@ -2213,9 +2187,7 @@
   // The initialization is idempotent, so we don't need locks.
   // In the future consider doing this via os::init_2().
 
-  if (os::is_MP()) {
-    BackOffMask = 0;
-  } else {
+  if (!os::is_MP()) {
     Knob_SpinLimit = 0;
     Knob_SpinBase  = 0;
     Knob_PreSpin   = 0;