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Re: Guile + Boehm GC: First Remarks
From: |
Ludovic Courtès |
Subject: |
Re: Guile + Boehm GC: First Remarks |
Date: |
Mon, 16 Oct 2006 09:46:06 +0200 |
User-agent: |
Gnus/5.110006 (No Gnus v0.6) Emacs/21.4 (gnu/linux) |
Hi Han-Wen,
Han-Wen Nienhuys <address@hidden> writes:
> Ludovic Courtès schreef:
>>
>> But please, relax about performance, we still haven't run any meaningful
>> benchmark. ;-)
>
> btw, is there any news on this patch? I'm quite keen on dumping
> LilyPond's Rational class in favor of Scheme rationals, but adding gc
> mark functions for that is just too much work; BGC would be a nice
> soluiton to this.
Well, no real news. My "not-so-meaningful benchmarks" (running a
loop[*]) reproductively show that "GBGC" is noticeably slower than "real
Guile" (1.5 to 2 times slower).
This could be due to various reasons.
* It could be that too much memory is being retained and subsequently
scanned. That's what I initially thought but after looking for this
kind of error for some time, I'm not so convinced that this is the
case.
* Initially, a fair amount of pointer-less memory (e.g., file or string
contents) ended up being scanned. I fixed this at some point, and now
I don't think there's any such error left.
* The GC settings should be tweaked. For instance, increasing BGC's
initial heap size (e.g., via the `GC_INITIAL_HEAP_SIZE' environment
variable) yields a noticeable improvement (though not sufficient).
* Any other reason listed (or not listed ;-)) at
http://www.hpl.hp.com/personal/Hans_Boehm/gc/debugging.html .
At this point, I'm a bit clueless not (yet) completely hopeless. ;-)
That is, I think it'd be worth keeping investigating this, but I'm
definitely looking for people with a fresh view on the topic to help!
:-)
I recently merged in changes from HEAD in my BGC branch. If you want to
give it a try and if you want to help, you can fetch it this way:
$ tla register-archive http://www.laas.fr/~lcourtes/software/arch-2005/
$ tla get address@hidden/guile-core--boehm-gc--1.9
Thanks,
Ludovic.
[*] It turns out that even tail-recursive call trigger memory
allocation, via `SCM_EXTEND_ENV ()'.
- Re: Guile + Boehm GC: First Remarks, Han-Wen Nienhuys, 2006/10/14
- Re: Guile + Boehm GC: First Remarks,
Ludovic Courtès <=
- Re: Guile + Boehm GC: First Remarks, Han-Wen Nienhuys, 2006/10/18
- Re: Guile + Boehm GC: First Remarks, Han-Wen Nienhuys, 2006/10/18
- Re: Guile + Boehm GC: First Remarks, Han-Wen Nienhuys, 2006/10/18
- Re: Guile + Boehm GC: First Remarks, Han-Wen Nienhuys, 2006/10/18
- Re: Guile + Boehm GC: First Remarks, Han-Wen Nienhuys, 2006/10/18
- Re: Guile + Boehm GC: First Remarks, Han-Wen Nienhuys, 2006/10/18