GETRUSAGE(2) BSD Programmer's Manual GETRUSAGE(2)
NAME
getrusage - get information about resource utilization
SYNOPSIS
#include <sys/time.h>
#include <sys/resource.h>
#define RUSAGESELF 0
#define RUSAGECHILDREN -1
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. The who parame-
ter is either 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; /* integral max resident set size */
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_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:
ruutime the total amount of time spent executing in user mode.
rustime the total amount of time spent in the system executing on
behalf of the process(es).
rumaxrss the maximum resident set size utilized (in kilobytes).
ruixrss 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 * ticks-of-
execution.
ruidrss an integral value of the amount of unshared memory residing
in the data segment of a process (expressed in units of
kilobytes * ticks-of-execution).
ruisrss an integral value of the amount of unshared memory residing
in the stack segment of a process (expressed in units of
kilobytes * ticks-of-execution).
ruminflt 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.
rumajflt the number of page faults serviced that required I/O activi-
ty.
runswap the number of times a process was swapped out of main memo-
ry.
ruinblock the number of times the file system had to perform input.
ruoublock the number of times the file system had to perform output.
rumsgsnd the number of IPC messages sent.
rumsgrcv the number of IPC messages received.
runsignals the number of signals delivered.
runvcsw the number of times a context switch resulted due to a pro-
cess voluntarily giving up the processor before its time
slice was completed (usually to await availability of a re-
source).
runivcsw the number of times a context switch resulted due to a high-
er priority process becoming runnable or because the current
process exceeded its time slice.
NOTES
The numbers ruinblock and ruoublock 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
Getrusage() returns -1 on error. The possible errors 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.
HISTORY
The getrusage function call appeared in 4.2BSD.
4th Berkeley Distribution March 26, 1993 2