int kernctl_snapshot_get_consumed(int fd, unsigned long *pos);
int kernctl_snapshot_get_produced(int fd, unsigned long *pos);
int kernctl_get_subbuf(int fd, unsigned long *pos);
int kernctl_snapshot_get_consumed(int fd, unsigned long *pos);
int kernctl_snapshot_get_produced(int fd, unsigned long *pos);
int kernctl_get_subbuf(int fd, unsigned long *pos);