Re: [BENCHMARK] 2.5.39-mm1

[Con Kolivas]

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On Tuesday 01 Oct 2002 8:20 pm, Andrew Morton wrote:
> Jens Axboe wrote:
> > On Mon, Sep 30 2002, Andrew Morton wrote:
> > > > io_load:
> > > > Kernel                  Time            CPU             Ratio
> > > > 2.4.19                  216.05          33%             3.19
> > > > 2.5.38                  887.76          8%              13.11
> > > > 2.5.38-mm3              105.17          70%             1.55
> > > > 2.5.39                  229.4           34%             3.4
> > > > 2.5.39-mm1              239.5           33%             3.4
> > >
> > > I think I'll set fifo_batch to 16 again...
> >
> > As not to compare oranges and apples, I'd very much like to see a
> > 2.5.39-mm1 vs 2.5.39-mm1 with fifo_batch=16. Con, would you do that?
> > Thanks!
>
> The presence of /proc/sys/vm/fifo_batch should make that pretty easy.

Thanks. That made it a lot easier and faster, and made me curious enough to 
create a family or very interesting results. All these are with 2.5.39-mm1 
with fifo_batch set to 1->16, average of three runs. The first result is the 
unmodified 2.5.39-mm1 (fifo_batch=32).

io_load:
Kernel                  Time            CPU%            Ratio
2.5.39-mm1              239.5           32              3.54
2539mm1fb16             131.2           57              1.94
2539mm1fb8              109.1           68              1.61
2539mm1fb4              146.4           51              2.16
2539mm1fb2              112.7           65              1.67
2539mm1fb1              125.4           60              1.85

What's most interesting is the variation was small until the number was <8; 
then the variation between runs increased. Dare I say it there appears to be 
a sweet spot in the results.

Con
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