#define MP_IOCTL_POLL (0x100 | 1)
#define MP_IOCTL_POLL_RD (0x0001)
#define MP_IOCTL_POLL_WR (0x0002)
#define MP_IOCTL_POLL_HUP (0x0004)
#define MP_IOCTL_POLL_ERR (0x0008)