Very slow redrawing when several windows in one frame

Very slow redrawing when several windows in one frame

[julien Barnier]

Hi,

I'm using the emacs-snaphot packages of emacs 24 under Debian.

One thing I've noticed is that as soon as I've got several windows opened in
one frame, window redrawing begin to be very slow (and the more open windows,
the slower it is). Any operation that requires a bit of redrawing (window
switching, minibuffer height change, etc.) is slow.

I asked on the #emacs IRC channel, and at least one other person had noticed
the same thing. I've tried with a "vanilla", so it seems it doesn't come from
my setup.

Is it a known bug ? Is there a workaround ?

Thanks in advance for any hint,

-- 
Julien

Re: Very slow redrawing when several windows in one frame

[Eli Zaretskii]

> From: julien Barnier <julien@nozav.org>
> Date: Wed, 9 Nov 2011 14:18:03 +0000 (UTC)
> 
> One thing I've noticed is that as soon as I've got several windows opened in
> one frame, window redrawing begin to be very slow (and the more open windows,
> the slower it is). Any operation that requires a bit of redrawing (window
> switching, minibuffer height change, etc.) is slow.

Please submit a bug report (with "M-x report-emacs-bug RET"), and
please show a recipe starting with "emacs -Q" for reproducing this
progressive slowdown.  If you need to visit specific files for
reproducing the problem, please try using files that are part of the
Emacs source tree, or else tell where to get those files.

Thanks in advance.

> Is it a known bug ?

Not as far as I Know.

> Is there a workaround ?

Bugs should be fixed, not worked around. ;-)

Re: Very slow redrawing when several windows in one frame

[Julien Barnier]

Eli Zaretskii <eliz <at> gnu.org> writes:

> Please submit a bug report (with "M-x report-emacs-bug RET"), and
> please show a recipe starting with "emacs -Q" for reproducing this
> progressive slowdown.  If you need to visit specific files for
> reproducing the problem, please try using files that are part of the
> Emacs source tree, or else tell where to get those files.

I tried to reproduce the bug, and I noticed for the first time that the
problem doesn't happen on my home computer (which is a netbook with fglrx
drivers), only on my computer at work (which is a more powerful workstation
with nvidia drivers). So it may not be directly related to emacs...

I'll try at work with different video settings.

> Bugs should be fixed, not worked around. 

Yep, and I'm very happy that there are clever and nice people who are able and
willing to fix them :-) So, many thanks for that !

Sincerely,

-- 
Julien