GETRUSAGE(3)GETRUSAGE(3)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 */
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.
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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 ALSOwait(2), see timers(5), gettimeofday(3) for details on the time
resolution.
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There is no way to obtain information about a child process that has not
yet terminated.
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