src/hotspot/cpu/x86/interp_masm_x86.cpp

*** 1189,1199 ****
      movptr(Address(lock_reg, mark_offset), swap_reg);
  
      assert(lock_offset == 0,
             "displaced header must be first word in BasicObjectLock");
  
!     if (os::is_MP()) lock();
      cmpxchgptr(lock_reg, Address(obj_reg, oopDesc::mark_offset_in_bytes()));
      if (PrintBiasedLockingStatistics) {
        cond_inc32(Assembler::zero,
                   ExternalAddress((address) BiasedLocking::fast_path_entry_count_addr()));
      }
--- 1189,1199 ----
      movptr(Address(lock_reg, mark_offset), swap_reg);
  
      assert(lock_offset == 0,
             "displaced header must be first word in BasicObjectLock");
  
!     lock();
      cmpxchgptr(lock_reg, Address(obj_reg, oopDesc::mark_offset_in_bytes()));
      if (PrintBiasedLockingStatistics) {
        cond_inc32(Assembler::zero,
                   ExternalAddress((address) BiasedLocking::fast_path_entry_count_addr()));
      }
*** 1286,1296 ****
  
      // zero for recursive case
      jcc(Assembler::zero, done);
  
      // Atomic swap back the old header
!     if (os::is_MP()) lock();
      cmpxchgptr(header_reg, Address(obj_reg, oopDesc::mark_offset_in_bytes()));
  
      // zero for simple unlock of a stack-lock case
      jcc(Assembler::zero, done);
  
--- 1286,1296 ----
  
      // zero for recursive case
      jcc(Assembler::zero, done);
  
      // Atomic swap back the old header
!     lock();
      cmpxchgptr(header_reg, Address(obj_reg, oopDesc::mark_offset_in_bytes()));
  
      // zero for simple unlock of a stack-lock case
      jcc(Assembler::zero, done);