Re: Larger GC thresholds for non-interactive Emacs

[Ihor Radchenko]

Stefan Monnier <monnier@iro.umontreal.ca> writes:

>> When we increase the threshold, free increases up to some value, but
>> that value is limited by the underlying code:
>
> A clarification: when you see
>
>     [...]
>     GC-898 p=1.0 total=18.7M free=7.3M thresold=18.7M
>     GC-898 p=1.0 total=18.8M free=7.3M thresold=18.8M
>     [...]
> ...

Thanks! I was totally misreading the results.

> The difference between the two cases is that when you have half of the
> heap made up of dead objects, there's a higher probability that some of
> those objects are clustered such that they make up a few complete
> 16kB blocks, whereas when only the dead objects represent only 10% of
> the heap, almost all 16kB blocks will contain a mis of dead and live
> objects and hence can't be returned to the malloc library.

I am again confused.
Does what you say imply that frequent GC with small threshold is not
good because it will have less dead objects and have higher chance of
fragmentation?

Best,
Ihor