Re: Time to drop the pre-dump phase in the build?

[Stefan Monnier <monnier@iro.umontreal.ca>]

> Another possibility is to just allocate enough space in the emacs image
> itself in BSS, then replace that mapping with a view of the dump file.

Indeed, that should work, assuming you can mmap into existing space.

> image base). Or we can make the dump file a section in the image, but at
> that point, we're starting to talk about portability problems again.

But not nearly as bad: the main dump problem we have is with generating
the `emacs' executable, whereas here we'd only need to generate the
"swap file" which is later loaded into the same executable.
Should still be a lot more portable.

> By the way: is it me, or are we dirtying far too much of the current emacs
> image? On my Emacs, we're dirtying (and COWing) 8MB; if I make
> Fgarbage_collect a no-op, that drops to 4MB.

For sure, GC will dirty up pretty much all pages that hold Lisp objects
(except for those in the purespace), because of the need to set/reset
the `mark' bit.


        Stefan