smp_mb
#undef smp_mb
#define smp_mb() aarch32_smp_mb()
#define smp_mb() barrier()
#define smp_mb() do { kcsan_mb(); __smp_mb(); } while (0)
#define smp_mb() asm volatile("dmb ish" ::: "memory")
#define smp_mb() RISCV_FENCE(rw, rw)
#define smp_mb() asm volatile("lock; addl $0,-132(%%rsp)" ::: "memory", "cc")
# define smp_mb() mb()
#define smp_mb() \
#define smp_mb() asm volatile("lock; addl $0,-132(%%rsp)" ::: "memory", "cc")
#define smp_mb() asm volatile("dmb ish" ::: "memory")
#define smp_mb() __sync_synchronize()