--- old/src/os_cpu/linux_x86/vm/atomic_linux_x86.hpp	2017-04-24 14:43:15.305874837 +0200
+++ new/src/os_cpu/linux_x86/vm/atomic_linux_x86.hpp	2017-04-24 14:43:15.229875072 +0200
@@ -42,23 +42,18 @@
 inline void Atomic::store_ptr(void*    store_value, volatile void*     dest) { *(void* volatile *)dest = store_value; }
 
 
-// Adding a lock prefix to an instruction on MP machine
-#define LOCK_IF_MP(mp) "cmp $0, " #mp "; je 1f; lock; 1: "
-
 inline jint     Atomic::add    (jint     add_value, volatile jint*     dest) {
   jint addend = add_value;
-  int mp = os::is_MP();
-  __asm__ volatile (  LOCK_IF_MP(%3) "xaddl %0,(%2)"
+  __asm__ volatile (  "lock xaddl %0,(%2)"
                     : "=r" (addend)
-                    : "0" (addend), "r" (dest), "r" (mp)
+                    : "0" (addend), "r" (dest)
                     : "cc", "memory");
   return addend + add_value;
 }
 
 inline void Atomic::inc    (volatile jint*     dest) {
-  int mp = os::is_MP();
-  __asm__ volatile (LOCK_IF_MP(%1) "addl $1,(%0)" :
-                    : "r" (dest), "r" (mp) : "cc", "memory");
+  __asm__ volatile (  "lock addl $1,(%0)" :
+                    : "r" (dest) : "cc", "memory");
 }
 
 inline void Atomic::inc_ptr(volatile void*     dest) {
@@ -66,9 +61,8 @@
 }
 
 inline void Atomic::dec    (volatile jint*     dest) {
-  int mp = os::is_MP();
-  __asm__ volatile (LOCK_IF_MP(%1) "subl $1,(%0)" :
-                    : "r" (dest), "r" (mp) : "cc", "memory");
+  __asm__ volatile (  "lock subl $1,(%0)" :
+                    : "r" (dest) : "cc", "memory");
 }
 
 inline void Atomic::dec_ptr(volatile void*     dest) {
@@ -89,19 +83,17 @@
 
 #define VM_HAS_SPECIALIZED_CMPXCHG_BYTE
 inline jbyte    Atomic::cmpxchg    (jbyte    exchange_value, volatile jbyte*    dest, jbyte    compare_value, cmpxchg_memory_order order) {
-  int mp = os::is_MP();
-  __asm__ volatile (LOCK_IF_MP(%4) "cmpxchgb %1,(%3)"
+  __asm__ volatile ("lock cmpxchgb %1,(%3)"
                     : "=a" (exchange_value)
-                    : "q" (exchange_value), "a" (compare_value), "r" (dest), "r" (mp)
+                    : "q" (exchange_value), "a" (compare_value), "r" (dest)
                     : "cc", "memory");
   return exchange_value;
 }
 
 inline jint     Atomic::cmpxchg    (jint     exchange_value, volatile jint*     dest, jint     compare_value, cmpxchg_memory_order order) {
-  int mp = os::is_MP();
-  __asm__ volatile (LOCK_IF_MP(%4) "cmpxchgl %1,(%3)"
+  __asm__ volatile ("lock cmpxchgl %1,(%3)"
                     : "=a" (exchange_value)
-                    : "r" (exchange_value), "a" (compare_value), "r" (dest), "r" (mp)
+                    : "r" (exchange_value), "a" (compare_value), "r" (dest)
                     : "cc", "memory");
   return exchange_value;
 }
@@ -112,10 +104,9 @@
 
 inline intptr_t Atomic::add_ptr(intptr_t add_value, volatile intptr_t* dest) {
   intptr_t addend = add_value;
-  bool mp = os::is_MP();
-  __asm__ __volatile__ (LOCK_IF_MP(%3) "xaddq %0,(%2)"
+  __asm__ __volatile__ ("lock xaddq %0,(%2)"
                         : "=r" (addend)
-                        : "0" (addend), "r" (dest), "r" (mp)
+                        : "0" (addend), "r" (dest)
                         : "cc", "memory");
   return addend + add_value;
 }
@@ -125,18 +116,16 @@
 }
 
 inline void Atomic::inc_ptr(volatile intptr_t* dest) {
-  bool mp = os::is_MP();
-  __asm__ __volatile__ (LOCK_IF_MP(%1) "addq $1,(%0)"
+  __asm__ __volatile__ ("lock addq $1,(%0)"
                         :
-                        : "r" (dest), "r" (mp)
+                        : "r" (dest)
                         : "cc", "memory");
 }
 
 inline void Atomic::dec_ptr(volatile intptr_t* dest) {
-  bool mp = os::is_MP();
-  __asm__ __volatile__ (LOCK_IF_MP(%1) "subq $1,(%0)"
+  __asm__ __volatile__ ("lock subq $1,(%0)"
                         :
-                        : "r" (dest), "r" (mp)
+                        : "r" (dest)
                         : "cc", "memory");
 }
 
@@ -149,10 +138,9 @@
 }
 
 inline jlong    Atomic::cmpxchg    (jlong    exchange_value, volatile jlong*    dest, jlong    compare_value, cmpxchg_memory_order order) {
-  bool mp = os::is_MP();
-  __asm__ __volatile__ (LOCK_IF_MP(%4) "cmpxchgq %1,(%3)"
+  __asm__ __volatile__ ("lock cmpxchgq %1,(%3)"
                         : "=a" (exchange_value)
-                        : "r" (exchange_value), "a" (compare_value), "r" (dest), "r" (mp)
+                        : "r" (exchange_value), "a" (compare_value), "r" (dest)
                         : "cc", "memory");
   return exchange_value;
 }
@@ -192,12 +180,12 @@
 
 extern "C" {
   // defined in linux_x86.s
-  jlong _Atomic_cmpxchg_long(jlong, volatile jlong*, jlong, bool);
+  jlong _Atomic_cmpxchg_long(jlong, volatile jlong*, jlong);
   void _Atomic_move_long(volatile jlong* src, volatile jlong* dst);
 }
 
 inline jlong    Atomic::cmpxchg    (jlong    exchange_value, volatile jlong*    dest, jlong    compare_value, cmpxchg_memory_order order) {
-  return _Atomic_cmpxchg_long(exchange_value, dest, compare_value, os::is_MP());
+  return _Atomic_cmpxchg_long(exchange_value, dest, compare_value);
 }
 
 inline intptr_t Atomic::cmpxchg_ptr(intptr_t exchange_value, volatile intptr_t* dest, intptr_t compare_value, cmpxchg_memory_order order) {