[SqF]Report of VI4 Project for Feb '02
Scott A Crosby
crosby at qwes.math.cmu.edu
Sat Feb 2 21:36:00 UTC 2002
On Sat, 2 Feb 2002, Henrik Gedenryd wrote:
> Scott A Crosby wrote:
> >> collections, including method dictionaries. (I haven't rechecked my
> >> facts, this is all from memory, so please correct me if I've got any
> >> of the details wrong.)
> > No, I preserve the old (flawed) behavior for method dictionaries, rather
> > than rebuilding a new image. True, this means that MethodDictionaries
> > should not be scaled beyond, say, 2000 or so methods. I don't consider
> > this a real problem.
> > Scott
> For simplicity reasons they ought to be changed too, to keep everything the
> same. Do you have any benchmarks for such a change?
No, doing that change requires both a VM change and a smalltalk-level
change, Rebuilding a new incompatible image in the process. The gain is
marginal. No MethodDictionary is 1/3 the size that would start to expose
> Also, changing the image format or rehashing all sets or any such should not
> be considered a problem with a new image format being instated anyway, so we
> ought to disregard such issues and just go for the best solution.
My earlier change is small-talk only, and leads to no image
BTW<, using 65537 as the multiplier is a *BAD* idea.
1*65537 \\ 4096
2*65537 \\ 4096
3*65537 \\ 4096
4*65537 \\ 4096
5*65537 \\ 4096
And why is it bad? :)
> PS. My thought was also that the two bits change should have a solid
> motivation. Even more so given the clear (yet not severe) disadvantages. "It
> might perhaps sometime become useful" is not enough IMHO.
I want to hear the rationale for it first. Does it save space? How much?
Is the performance degradation minor?
I'm beginning to think the future should be a completely new
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