NFS_HZ
#define NFS_MINRTO (NFS_HZ >> 2)
#define NFS_MAXRTO (20 * NFS_HZ)
#define NFS_INITRTT (NFS_HZ << 3)
#define NFS_TIMEO (1 * NFS_HZ) /* Default timeout = 1 second */
#define NFS_MINTIMEO (1 * NFS_HZ) /* Min timeout to use */
#define NFS_MAXTIMEO (60 * NFS_HZ) /* Max timeout to backoff to */
nmp->nm_timeo = (argp->timeo * NFS_HZ + 5) / 10;