GETRUSAGE(2)GETRUSAGE(2)NAMEgetrusage - 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 */
int ru_maxrss; /* not used */
int ru_ixrss; /* not used */
int ru_idrss; /* not used */
int ru_isrss; /* not used */
int ru_minflt; /* not used */
int ru_majflt; /* not used */
int ru_nswap; /* not used */
int ru_inblock; /* block input operations */
int ru_oublock; /* block output operations */
int ru_msgsnd; /* messages sent */
int ru_msgrcv; /* messages received */
int ru_nsignals; /* signals received */
int ru_nvcsw; /* voluntary context switches */
int 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).
Currently, this field isn't valid.
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 memory pages in use each
time the internal system clock ticks and then averaging
over 1 second intervals. Currently, this field isn't
valid.
ru_idrss an integral value of the amount of unshared memory
residing in the data segment of a process (expressed in
units of kilobytes * seconds-of-execution). Currently,
this field isn't valid.
ru_isrss an integral value of the amount of unshared memory
residing in the stack segment of a process (expressed in
units of kilobytes * seconds-of-execution). Currently,
this field isn't valid.
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.
Currently, this field isn't valid.
ru_majflt the number of page faults serviced that required I/O
activity. Currently, this field isn't valid.
ru_nswap the number of times a process was “swapped” out of main
memory. Currently, this field isn't valid.
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 ALSOgettimeofday(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)
