bug#19393: 25.0.50; Emacs cannot determine coding system of ISO-8859 encoded files

[Eli Zaretskii <eliz@gnu.org>]

> From: Wolfgang Jenkner <wjenkner@inode.at>
> Cc: 19393@debbugs.gnu.org
> Date: Thu, 18 Dec 2014 17:36:19 +0100
> 
> On Thu, Dec 18 2014, Eli Zaretskii wrote:
> 
> >> -  cygwin|mingw32|freebsd|irix6-5) use_mmap_for_buffers=yes ;;
> >> +  cygwin|mingw32|irix6-5) use_mmap_for_buffers=yes ;;
> [...]
> >> However, this still took around 10 minutes (I tested with emacs -Q in
> >> both cases, of course).
> >
> > That's expected: when you disable mmap, Emacs uses ralloc.c, which
> > still has this problem.
> 
> Shouldn't other systems for which the native malloc is not used have
> a similar problem then?

There are almost none of them.  But yes, those which do should have a
similar problem.

> > Btw, is this with the compressed file or after decompressing it?  My
> > guess is the former.
> 
> No, with the uncompressed file.

Then it's probably some inefficiency in insert-file-contents, when it
is called to revert a buffer.  If you have time, please take a look
what happens there, I suspect we reallocate the buffer in very small
chunks, instead of doing it with larger increments.  (With compressed
files, it's hard to do, because the size of the uncompressed file is
not known in advance.)

Thanks.