Re: Benchmark - 2nd run

[Matthew Dillon <dillon@xxxxxxxxxxxxxxxxxxxx>]

:Finally to test if there is a problem with the compiler I used the lorenz
:benchmark (it simply does raw math computations, and does not use much
:memory):
:
:Lorenz on 5.1
:4.9binary: 15.77 real        15.73 user         0.01 sys
:5.1binary: 16.52 real        16.51 user         0.00 sys
:5.2binary: 16.36 real        16.32 user         0.02 sys
:
:Lorenz on 5.2
:4.9binary: 19.35 real        18.12 user         1.14 sys
:5.1binary: 27.65 real        26.05 user         1.48 sys
:5.2binary: 29.61 real        27.60 user         1.87 sys
:
:The 5.1 results indicate that there is no problem with the compiler
:generated code, but I don't know how to interpret the 5.2 results: I
:would expect also a bad behavior with the 4.9 binary (all are static)
:
:Then I booted a uniprocessor kernel and reran the latest test:
:
:Lorenz on 5.2 UP
:4.9binary: 15.80 real        15.71 user         0.02 sys
:5.1binary: 22.57 real        22.45 user         0.03 sys
:5.2binary: 24.16 real        24.05 user         0.03 sys
:
:Jean-Marc

    I think your Lorenz results are the most interesting of the
    lot.  It definitely shows that there's something lala going
    on in 5.2-SMP-land.  The system overhead should be near 0
    and it's way up there at almost 2 seconds!

    Check 'hz' on 5.2.  'sysctl kern.clockrate'.  It kinda looks
    like its going wild on 5.2.  If it is not set to 100 you can
    force it with a /boot/loader.conf setting 'kern.hz=100'.

    If it isn't that it's got to be something else simple-stupid.
    The unusual system times for a user-cpu-bound program would 
    explain the horrible results on the other benchmarks.

					-Matt
					Matthew Dillon 
					<dillon@xxxxxxxxxxxxx>