Re: Merging scratch/no-purespace to remove unexec and purespace

[Stefan Kangas]

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

>>> We, the maintainers, believe that the scratch/no-purespace branch is
>>> now ready to merge, and would appreciate any final feedback, testing,
>>> and code reviews.  Specifically, the branch has been primarily tested
>>> on GNU/Linux and macOS, so testing on other systems would be greatly
>>> appreciated.
>>
>> Do you have an estimate what removing purespace will cost in terms of GC
>> time?  I mean something like "1ms per collection".  Or perhaps a
>> suggestion how I could measure it?
>
> In the pdump case it should have no effect at all, or maybe even
> a slight *speedup*.
>
> That's because the pdump already fails to take advantage of the
> purespace (i.e. the GC traces through the purespace like the rest of
> the heap).

I'll note that the best solution to that is to have a generational GC
instead.  Simple, right?

It's not entirely unrelated though: among other things, one reason why
merging this would be good is that it would reportedly simplify the work
on the igc branch.  And indeed any GC-related work now or in future.