GETRUSAGE(3)                                                      GETRUSAGE(3)


NAME
     getrusage - get information about resource utilization

SYNOPSIS
     #include <sys/time.h>
     #include <sys/resource.h>

     #define RUSAGE_SELF      0         /* calling process */
     #define RUSAGE_CHILDREN  -1        /* terminated child processes */

     int getrusage(int who, struct rusage *rusage);

DESCRIPTION
     Getrusage returns information describing the resources utilized by the
     current process, or all its terminated child processes.  This routine is
     provided for compatibility with 4.3BSD.

     The who parameter is one of RUSAGE_SELF or RUSAGE_CHILDREN.  The buffer
     to which rusage points will be filled in with the following structure:

          struct rusage {
                 struct timeval ru_utime;/* user time used */
                 struct timeval ru_stime;/* system time used */
                 long   ru_maxrss;
                 long   ru_ixrss;     /* integral shared memory size */
                 long   ru_idrss;     /* integral unshared data " */
                 long   ru_isrss;     /* integral unshared stack " */
                 long   ru_minflt;    /* page reclaims */
                 long   ru_majflt;    /* page faults */
                 long   ru_nswap;     /* swaps */
                 long   ru_inblock;   /* block input operations */
                 long   ru_oublock;   /* block output operations */
                 long   ru_msgsnd;    /* messages sent */
                 long   ru_msgrcv;    /* messages received */
                 long   ru_nsignals;  /* signals received */
                 long   ru_nvcsw;     /* voluntary context switches */
                 long   ru_nivcsw;    /* involuntary " */
          };

     The fields are interpreted as follows:

     ru_utime       the total amount of time spent executing in user mode.

     ru_stime       the total amount of time spent in the system executing on
                    behalf of the process(es).

     ru_maxrss      the maximum resident set size utilized (in kilobytes).

     ru_minflt      the number of page faults serviced without any I/O
                    activity; here I/O activity is avoided by "reclaiming" a
                    page frame from the list of pages awaiting reallocation.


     ru_majflt      the number of page faults serviced that required I/O
                    activity.

     ru_nswap       the number of times a process was "swapped" out of main
                    memory.

     ru_inblock     the number of times the file system had to perform input.

     ru_oublock     the number of times the file system had to perform output.

     ru_msgsnd      the number of messages sent over sockets.

     ru_msgrcv      the number of messages received from sockets.

     ru_nsignals    the number of signals delivered.

     ru_nvcsw       the number of times a context switch resulted due to a
                    process voluntarily giving up the processor before its
                    time slice was completed (usually to await availability of
                    a resource).

     ru_nivcsw      the number of times a context switch resulted due to a
                    higher priority process becoming runnable or because the
                    current process exceeded its time slice.

     The remaining fields are not maintained by the IRIX kernel and are set to
     zero by this routine.

NOTES
     The numbers ru_inblock and ru_oublock account only for real I/O; data
     supplied by the caching mechanism is charged only to the first process to
     read or write the data.

     The ru_msgsnd and ru_msgrcv fields keep count of IPC messages sent and
     received via the socket (2) interface only.

     The ru_maxrss field count includes shared pages.

ERRORS
     The possible errors for getrusage are:

     [EINVAL]       The who parameter is not a valid value.

     [EFAULT]       The address specified by the rusage parameter is not in a
                    valid part of the process address space.

SEE ALSO
     wait(2), see timers(5), gettimeofday(3) for details on the time
     resolution.


BUGS
     There is no way to obtain information about a child process that has not
     yet terminated.


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