NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | CONFORMING TO | NOTES | SEE ALSO | COLOPHON
GETRUSAGE(2) Linux Programmer's Manual GETRUSAGE(2)
getrusage - get resource usage
#include <sys/time.h>
#include <sys/resource.h>
int getrusage(int who, struct rusage *usage);
getrusage() returns resource usage measures for who, which can be one of the
following:
RUSAGE_SELF
Return resource usage statistics for the calling process, which is the
sum of resources used by all threads in the process.
RUSAGE_CHILDREN
Return resource usage statistics for all children of the calling
process that have terminated and been waited for. These statistics
will include the resources used by grandchildren, and further removed
descendants, if all of the intervening descendants waited on their
terminated children.
RUSAGE_THREAD (since Linux 2.6.26)
Return resource usage statistics for the calling thread.
The resource usages are returned in the structure pointed to by usage, which
has the following form:
struct rusage {
struct timeval ru_utime; /* user time used */
struct timeval ru_stime; /* system time used */
long ru_maxrss; /* maximum resident set size */
long ru_ixrss; /* integral shared 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 */
};
On success, zero is returned. On error, -1 is returned, and errno is set
appropriately.
EFAULT usage points outside the accessible address space.
EINVAL who is invalid.
SVr4, 4.3BSD. POSIX.1-2001 specifies getrusage(), but only specifies the
fields ru_utime and ru_stime.
RUSAGE_THREAD is Linux-specific.
Resource usage metrics are preserved across an execve(2).
Including <sys/time.h> is not required these days, but increases portability.
(Indeed, struct timeval is defined in <sys/time.h>.)
In Linux kernel versions before 2.6.9, if the disposition of SIGCHLD is set to
SIG_IGN then the resource usages of child processes are automatically included
in the value returned by RUSAGE_CHILDREN, although POSIX.1-2001 explicitly
prohibits this. This non-conformance is rectified in Linux 2.6.9 and later.
The structure definition shown at the start of this page was taken from 4.3BSD
Reno. Not all fields are meaningful under Linux. In Linux 2.4 only the
fields ru_utime, ru_stime, ru_minflt, and ru_majflt are maintained. Since
Linux 2.6, ru_nvcsw and ru_nivcsw are also maintained.
See also the description of /proc/PID/stat in proc(5).
getrlimit(2), times(2), wait(2), wait4(2), clock(3), clock_gettime(3)
This page is part of release 3.11 of the Linux man-pages project. A
description of the project, and information about reporting bugs, can be found
at http://www.kernel.org/doc/man-pages/.
Linux 2008-10-06 GETRUSAGE(2)