GETRUSAGE(2)							System Calls Manual						      GETRUSAGE(2)

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 */

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

DESCRIPTION

       Getrusage  returns  information	describing  the resources utilized by the current process, or all its terminated child processes.  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 text memory size */
		      long    ru_idrss; 	      /* integral unshared data size */
		      long    ru_isrss; 	      /* integral unshared stack size */
		      long    ru_minflt;	      /* page reclaims */
		      long    ru_majflt;	      /* page faults */
		      long    ru_ovly;		      /* overlay changes */
		      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 context switches */
	      };

       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_ixrss       an "integral" value indicating the amount of memory used by the text segment that was also  shared  among  other	processes.
		      This  value is expressed in units of kilobytes * seconds-of-execution and is calculated by summing the number of shared mem-
		      ory pages in use each time the internal system clock ticks and then averaging over 1 second intervals.

       ru_idrss       an integral value of the amount of unshared memory residing in the data segment of a process (expressed in  units  of  kilo-
		      bytes * seconds-of-execution).

       ru_isrss       an  integral  value of the amount of unshared memory residing in the stack segment of a process (expressed in units of kilo-
		      bytes * seconds-of-execution).

       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.

       the number of times a process requested a text overlay switch -
		      only available under 2_10BSD.

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

       ru_msgsnd      the number of IPC messages sent.

       ru_msgrcv      the number of IPC messages received.

       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.

NOTES

       The  numbers  ru_inblock  and  ru_outblock  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.

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

       gettimeofday(2), wait(2)

BUGS

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

4th Berkeley Distribution					   May 13, 1986 						      GETRUSAGE(2)