Re: Opportunistic GC

[Eli Zaretskii]

> From: Pip Cet <pipcet@gmail.com>
> Date: Mon, 8 Mar 2021 16:35:30 +0000
> Cc: rudalics@gmx.at, Stefan Monnier <monnier@iro.umontreal.ca>, 
> emacs-devel@gnu.org
> 
> > And how do you make sure the mark bits will be on a different/separate
> > page?
> 
> We allocate cons blocks aligned to physical pages.

What is a "physical page" for this purpose?  You want a page whose
size will make sure you don't trigger copy-on-write when you change
some bit -- are you sure that this size is always the same as the
"page size" we use for so-called "page-aligned" allocations?

And if the answer is YES, how future-proof is it?

> What am I missing?

I don't know whether we are missing something.  We are on new ground
here: we never cared in Emacs about physical layout of memory, at
least not so much.