Re: MPS signals and Emacs

[Gerd Möllmann]

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Gerd Möllmann <gerd.moellmann@gmail.com>
>> Cc: eggert@cs.ucla.edu,  eller.helmut@gmail.com,  emacs-devel@gnu.org
>> Date: Mon, 22 Apr 2024 12:22:25 +0200
>> 
>> Eli Zaretskii <eliz@gnu.org> writes:
>> 
>> > Doesn't copying GC work by copying live objects to a new memory
>> > region, and then freeing the old region?  If so, if some objects
>> > cannot be moved, how can the old region be freed?
>> 
>> Yes. A simple precise GC (no support for ambiguous references) might
>> work with 2 regions, which are usually called to-space and froms-space.
>> When a GC happens, everything live is copied from from-space to
>> to-space. At the end, to-space has all live objects, and both spaces can
>> switch roles in the next GC.
>
> Btw, does this mean that a copying GC will make the memory used for
> live objects roughly doubled in size?

Yes, exactly. It's a well-known problem.