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.