 used */
    float ru_stime (sec.) /* system time used */
    int  ru_maxrss;       /* maximum resident set size */
    int  ru_ixrss;        /* currently 0 */
    int  ru_idrss;        /* integral resident set size */
    int  ru_isrss;        /* currently 0 */
    int  ru_minflt;       /* page faults without physical I/O */
    int  ru_majflt;       /* page faults with physical I/O */
    int  ru_nswap;        /* number of swaps */
    int  ru_inblock;      /* block input operations */
    int  ru_oublock