Re: new emacs24 settings (was: Re: Performance problems (CPU 100%) with NULs in files)

[Le Wang]

filed:

bug#9588: Acknowledgement (24.0.50; bidi-display-reordering slowing
scrolling more than expected)

On Sat, Sep 24, 2011 at 3:02 AM, Eli Zaretskii <eliz@gnu.org> wrote:
>
> > Date: Sat, 24 Sep 2011 02:32:24 +0800
> > From: Le Wang <l26wang@gmail.com>
> > Cc: help-gnu-emacs@gnu.org
> >
> >
> > [1:text/plain Hide]
> >
> > On Sat, Sep 24, 2011 at 1:58 AM, Eli Zaretskii <eliz@gnu.org> wrote:
> >
> > >
> > > > next-line
> > > What was the value of line-move-visual?  Under the default non-nil
> > > setting, next-line is pretty expensive.
> > >
> >
> > it was t, setting it to nil didn't help bibi-display much.
> >
> >
> > >  > >  What kind of text?  What was the major mode in that buffer?
> > > >
> > > > emacs-lisp large file
> > >
> > > How large?
> > >
> > >
> > allout.el >200k not very large.  large enough to scroll continuously  for 10
> > seconds of so.
> >
> > Does it matter whether you are close to the file's beginning or to its
> > > end?
> > >
> > > Does anything change if, after visiting the file, you first type
> > >
> > >  M-: (font-lock-default-fontify-buffer) RET
> > >
> > and only then try scrolling?
> > >
> >
> > no.
> >
> >
> > > > I also use full font-lock salad colors with "Consolas" font on Windows.
> > > > Also I use several minor-modes that add pre or post-command-hooks.
> > >
> > > If you remove those pre/post-command hooks, does the scrolling speed
> > > improve significantly?  Can you find a hook that has the most profound
> > > effect?
> >
> >
> > no it does not.  the effect of all hooks is about 2-3% CPU.
> >
> >  > > Does it behave better if you set redisplay-dont-pause to a non-nil
> > > > > value?  This will be the default in Emacs 24.
> > > > >
> > > >
> > > > It's not making a noticeable difference.
> > >
> > > With or without bidi-display-reordering?  I asked about its effect
> > > when bidi-display-reordering is left at its default t value.
> > >
> >
> > I tried it with bidi and without, difference wasn't huge.
>
> What you tell is very strange, because any reason I could think of are
> contradicted by one or more of your answers.
>
> Please file a bug report with the following info:
>
>  . your full .emacs file (assuming the problem is not visible in
>   "emacs -Q"; if it is, no need for .emacs)
>
>  . the name of some Lisp file that is part of Emacs which exhibits a
>   similar slowdown, and that slowdown disappears when you turn off
>   bidi-display-reordering.  alternatively, if you can post the
>   specific Lisp file you used in this testing, that'd be best.
>
> With this info, I can look into the problem and see what causes it.
>
> Thanks in advance.
>
>



--
Le