VTIMES(3) BSD Library Functions Manual VTIMES(3)NAMEvtimes — get information about resource utilization
SYNOPSIS
#include <sys/vtimes.h>
vtimes(struct vtimes *par_vm, struct vtimes *ch_vm);
DESCRIPTION
This interface is obsoleted by getrusage(2). It is available from the
compatibility library, libcompat.
The vtimes() function returns accounting information for the current
process and for the terminated child processes of the current process.
Either par_vm or ch_vm or both may be 0, in which case only the informa‐
tion for the pointers which are non-zero is returned.
After the call, each buffer contains information as defined by the con‐
tents of the include file /usr/include/sys/vtimes.h:
struct vtimes {
int vm_utime; /* user time (*HZ) */
int vm_stime; /* system time (*HZ) */
/* divide next two by utime+stime to get averages */
unsigned vm_idsrss; /* integral of d+s rss */
unsigned vm_ixrss; /* integral of text rss */
int vm_maxrss; /* maximum rss */
int vm_majflt; /* major page faults */
int vm_minflt; /* minor page faults */
int vm_nswap; /* number of swaps */
int vm_inblk; /* block reads */
int vm_oublk; /* block writes */
};
The vm_utime and vm_stime fields give the user and system time respec‐
tively in 60ths of a second (or 50ths if that is the frequency of wall
current in your locality.) The vm_idrss and vm_ixrss measure memory
usage. They are computed by integrating the number of memory pages in
use each over CPU time. They are reported as though computed discretely,
adding the current memory usage (in 512 byte pages) each time the clock
ticks. If a process used 5 core pages over 1 cpu-second for its data and
stack, then vm_idsrss would have the value 5*60, where vm_utime+vm_stime
would be the 60. The Vm_idsrss argument integrates data and stack seg‐
ment usage, while vm_ixrss integrates text segment usage. The Vm_maxrss
function reports the maximum instantaneous sum of the text+data+stack
core-resident page count.
The vm_majflt field gives the number of page faults which resulted in
disk activity; the vm_minflt field gives the number of page faults
incurred in simulation of reference bits; vm_nswap is the number of swaps
which occurred. The number of file system input/output events are
reported in vm_inblk and vm_oublk These numbers 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.
SEE ALSOtime(2), wait3(2), getrusage(2)HISTORY
The vlimit() function appeared in 4.2BSD.
4th Berkeley Distribution June 4, 1993 4th Berkeley Distribution
