NAME
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cputime, times, cycles – cpu time in this process and children |
SYNOPSIS
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#include <u.h> #include <libc.h> long times(long t[4]) double cputime(void)
void cycles(uvlong *cyclep) |
DESCRIPTION
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If t is non–null, times fills it in with the number of milliseconds
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
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/sys/src/libc/9sys /sys/src/libc/*/cycles.[cs] |
SEE ALSO
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exec(2), cons(3) |
BUGS
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Only 386 processors starting with the Pentium have timestamp counters;
calling cycles on earlier processors may execute an illegal instruction. |