Re: [Chicken-hackers] Experiments with heap shrinkage, -:hs

[Kooda]

On Fri, 19 May 2017 15:29:56 +0200 (CEST) Sven Hartrumpf
<address@hidden> wrote:
> Hi all.
> 
> I would like to experiment with heap shrinking (-:hs) for long
> running, memory/GC intensive processes.
> 
> I checked runtime.c and I read the following shrink condition:
> 
> count < percentage(percentage(heap_size, C_heap_shrinkage),
> DEFAULT_HEAP_SHRINKAGE_USED)
> 
> This would imply that heap usage must be < 12.5 % to lead to a heap
> shrink because C_heap_shrinkage (via DEFAULT_HEAP_SHRINKAGE) is 50 %
> and DEFAULT_HEAP_SHRINKAGE_USED is 25 %.
> This (< 12.5 %) is very unlikely for many applications :-)
> How about:
> 
> count < percentage(heap_size, DEFAULT_HEAP_SHRINKAGE_USED)  ?
> 
> Ciao
> Sven
> 

My 2 cents, I don’t know much about CHICKEN’s GC yet:

This sounds good to me, the current behaviour seems a little bit
strange.

Maybe we could also introduce a new runtime flag that would indicate at
which point we trigger heap shrinkage (that would replace
DEFAULT_HEAP_SHRINKAGE_USED)?