-#ifndef __NR_ioprio_set
-#define __NR_ioprio_set 442
-#define __NR_ioprio_get 443
-#endif
-
-#ifndef __NR_fadvise64
-#define __NR_fadvise64 413
-#endif
-
-#define nop do { } while (0)
-#define read_barrier() __asm__ __volatile__("mb": : :"memory")
+#define nop do { } while (0)
+#define read_barrier() __asm__ __volatile__("mb": : :"memory")
+#define write_barrier() __asm__ __volatile__("wmb": : :"memory")