Re: [BENCHMARK] 2.4.{18,19{-ck9},20rc1{-aa1}} with contest

[Andrea Arcangeli]

On Sun, Nov 10, 2002 at 11:09:42AM +0100, Jens Axboe wrote:
> On Sun, Nov 10 2002, Con Kolivas wrote:
> > >The default is 2048. How long does the io_load test take, or rather how
> > >many tests are appropriate to do? To get a good picture of how it looks
> > >you should probably try: 0, 8, 16, 64, 128, 512. Once you get some of
> > >these results, it will be easier to determine which area(s) would be
> > >most interesting to further explore.
> > 
> > The io_load test takes as long as the time in seconds shown on the table. At 
> > least 3 tests are appropriate to get a reasonable average [runs is in square 
> > parentheses]. Therefore it takes about half an hour per run. Luckily I had 
> > the benefit of a night to set up a whole lot of runs:
> > 
> > io_load:
> > Kernel [runs]           Time    CPU%    Loads   LCPU%   Ratio
> > 2420rc1r0 [3]           489.3   15      36      10      6.85
> > 2420rc1r8 [3]           485.5   15      35      10      6.80
> > 2420rc1r16 [3]          570.4   12      43      10      7.99
> > 2420rc1r32 [3]          570.1   12      42      10      7.98
> > 2420rc1r64 [3]          575.0   12      43      10      8.05
> > 2420rc1r128 [3]         611.4   11      46      10      8.56
> > 2420rc1r256 [3]         646.2   11      49      10      9.05
> > 2420rc1r512 [3]         603.7   12      45      10      8.46
> > 2420rc1r1024 [3]        693.9   10      53      10      9.72
> > 2.4.20-rc1 [2]          1142.2  6       90      10      16.00
> > 
> > Test hardware is 1133Mhz P3 laptop with 5400rpm ATA100 drive. I don't doubt 
> > the response curve would be different for other hardware.
> 
> That looks pretty good, the behaviour in 2.4.20-rc1 is no sanely tunable
> unlike before. Could you retest the whole contest suite with 512 as the
> default value? It looks like a good default for 2.4.20.

agreed, btw, a 2048 before the fixes would mean much less than now.

Andrea