CLOCK(8)

NAME
clock - report timing attributes

SYNOPSIS
clock

DESCRIPTION
clock reports the timing interval, ENOUGH, timing overhead TIMING_OVERHEAD, and loop overhead LOOP_OVERHEAD. The required timing interval is determined experimentally to ensure that the timing results are accurate to within 1% in the spite of the system clock resolution and measurement overheads. It is necessary to measure ENOUGH experimentally because system clock resolution varies widely across systems, from as large as 10 milliseconds to as small as 1 microsecond, a range of four orders of magnitude. The timing overheads and loop overheads are used by the timing harness timing(3) to remove the various overheads from the measured times.

OUTPUT
The various results are reported in micro-seconds, e.g.,

    ENOUGH=5000
    TIMING_OVERHEAD=7.000000
    LOOP_OVERHEAD=0.000004
    # version 2.0

ACKNOWLEDGEMENT
Funding for the development of this tool was provided by Sun Microsystems Computer Corporation.

SEE ALSO
lmbench(8), lmbench(3), timing(3).