Re: MPS codegen

[Eli Zaretskii]

> From: Gerd Möllmann <gerd.moellmann@gmail.com>
> Cc: eller.helmut@gmail.com,  emacs-devel@gnu.org
> Date: Fri, 14 Jun 2024 09:30:31 +0200
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> >> From: Gerd Möllmann <gerd.moellmann@gmail.com>
> >> Cc: Eli Zaretskii <eliz@gnu.org>,  emacs-devel@gnu.org
> >> Date: Thu, 13 Jun 2024 21:37:41 +0200
> >> 
> >> Maybe one could reserve + commit a suitable block upfront, maybe as one
> >> big IGC_OBJ_PAD, and use read(2) or so to read the .pdmp into that
> >> block.
> >
> > Wouldn't that slow down startup?  pdumper uses memory-mapped files to
> > make that as fast as possible, and for a good reason: at the time
> > pdumper was introduced people objected to have startup slow down even
> > by a few hundreds of milliseconds.
> 
> I don't know. Did pdumper do many reads that were replaced with one
> mmap? This one could do one large read instead of one mmap.

pdumper never did any reads, it was implemented from the get-go to use
mmap and equivalent APIs.