MEMBARRIER_CMD_QUERY
case MEMBARRIER_CMD_QUERY:
status = sys_membarrier(MEMBARRIER_CMD_QUERY, 0);
status = sys_membarrier(MEMBARRIER_CMD_QUERY, 0);
ret = sys_membarrier(MEMBARRIER_CMD_QUERY, flags);
int cmd = MEMBARRIER_CMD_QUERY, flags = 1;