CPUTIME(2) CPUTIME(2)
NAME
cputime, times, cycles - cpu time in this process and
children
SYNOPSIS
#include <u.h>
#include <libc.h>
int times(long t[4])
double cputime(void)
void cycles(uvlong *cyclep)
DESCRIPTION
If t is non-null, times fills it in with the number of mil-
liseconds spent in user code, system calls, child processes
in user code, and child processes in system calls. Cputime
returns the sum of those same times, converted to seconds.
Times returns the elapsed real time, in milliseconds, that
the process has been running.
These functions read /dev/cputime, opening that file when
they are first called.
Cycles reads the processor's timestamp counter of cycles
since reset, if any, and stores it via cyclep. Currently
supported architectures are 386, amd64, and power; on all
others, cycles will store zero.
SOURCE
/sys/src/libc/9sys
/sys/src/libc/*/cycles.[cs]
SEE ALSO
exec(2), cons(3)
BUGS
Only 386 processors starting with the Pentium have timestamp
counters; calling cycles on earlier processors may execute
an illegal instruction.
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