Re: find-file takes forever on slow network file systems and very deep directories

[Eli Zaretskii <eliz@gnu.org>]

> Date: Thu, 25 Sep 2008 09:26:59 -0700
> From: "Andrzej Leszczynski" <andy.leszczynski@gmail.com>
> 
> > It looks like the VC package could be the culprit: there are many
> > filesystem calls that look for files such as:
> > 
> >   W:\dir1\dir2\dir3\dir4\dir5\dir6\dir7\.bzr\checkout\
> >   W:\dir1\dir2\dir3\dir4\dir5\dir6\dir7\dir8\dir9\dirA\dirB\dirC\RCS\ 
> >   W:\dir1\dir2\dir3\dir4\dir5\dir6\dir7\dir8\dir9\dirA\dirB\dirC\CVS\Entries
> >   W:\dir1\dir2\dir3\dir4\dir5\dir6\dir7\dir8\dir9\dirA\dirB\dirC\.svn\entries
> >   W:\dir1\dir2\dir3\dir4\dir5\dir6\dir7\dir8\dir9\dirA\dirB\dirC\SCCS\
> >   W:\dir1\dir2\dir3\dir4\dir5\dir6\dir7\dir8\dir9\dirA\dirB\dirC\file.c\_MTN\
> >   W:\dir1\dir2\dir3\dir4\dir5\dir6\dir7\dir8\dir9\dirA\dirB\{arch}\
> >   W:\dir1\dir2\dir3\dir4\dir5\dir6\dir7\dir8\dir9\dirA\dirB\dirC\file.c\MCVS\
> >
> > This greatly enlarges the number of files and directories Emacs needs
> > to `stat'.
> >
> > Can you try evaluating the following expression (in Emacs 22.x):
> >
> >  (remove-hook 'find-file-hook 'vc-find-file-hook)
> >
> > and then see if the speed of `find-file' increases significantly as a
> > result?
> >
> 
> I had the same thought - see in the USENET thread - but I did not have
> the clue how to disable it. Now it  loads the file much faster,
> although it still _stats_ all the dirs up to the root (drive C:)

Does anyone have any thoughts on how to avoid such a significant
performance hit (15 sec for a simple `find-file') on Samba volumes, as
opposed to just 2 seconds in Emacs 21.x, which didn't automatically
have `vc-find-file-hook' on the `find-file-hook' list?

If there's no good cure, we should at least provide a user option to
avoid putting `vc-find-file-hook' on `find-file-hook', or maybe allow
finer-grain control of it, like per filesystem.

Thoughts?