[squeak-dev] squeak performance

Levente Uzonyi leves at elte.hu
Fri May 21 17:49:17 UTC 2010


On Fri, 21 May 2010, Alain_Rastoul wrote:

> Hello,
>
> I recently tryed then 4.1 and discovered a strange behavior that appearead
> to be true with the 3.10 also.
> The test is simply running benchFib in series of runs.
> If I run the test 10 times, on of the run is about 2-3 times faster than the
> others, and I can't explain that.
>
> 10 timesRepeat: [
> | r t |
>   t := Time millisecondsToRun: [r := 26 benchFib].
>   Transcript show: ((r * 1000) // t) ; cr.
> ]

I can't reproduce this. I think it's just noise from your OS. But try to 
evaluate this:

[
 	((1 to: 100)
 		collect: [ :run |
 			(Integer >> #benchFib) flushCache.
 			[ 26 benchFib ] timeToRunWithoutGC ]) sort ] valueAt: 80.

If you get the same results, then GC and caching doesn't change the 
behavior, so you can be pretty sure that it's just OS-noise. Try 
increasing the priority of Squeak's process and repeat the tests.


Levente

>
> will give me 10 numbers about 2486297 (one of the runs)
> but one run will give me 10 numbers about 6773017.
> I stopped all I could stop on my laptop and nothing else but squeak is
> running...
> I made a TimeProfileBrowser and the inner loop of the profile seems to show
> that primitives are more than 2 times faster.
> (and everything seems 2 times faster)
> Anybody noticed that (I searched the web but found nothing) ?
> primitive calls ?
> methodCache?
>
>
> Best regards,
>
> Alain
>
>
>
>
>



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