Test R+locked+mb

C R+locked+mb

{}


P0(int* y,spinlock_t* lo,int* x) {
  spin_lock(lo);
  WRITE_ONCE(*x,1);
  spin_unlock(lo);
  spin_lock(lo);
  WRITE_ONCE(*y,1);
  spin_unlock(lo);
}

P1(int* y,int* x) {
  WRITE_ONCE(*y,2);
  smp_mb();
  int r0 = READ_ONCE(*x);
}

Observed
    y=2; 1:r0=0;