Subject: Re: bug#2056: 23.0.60; Enabling flyspell degrades performance

From: Ian Eure <[email-masked]>
Date: Thu, 26 Mar 2009 14:22:22 -0700

On Jan 30, 2009, at 4:11 AM, Agustin Martin wrote:

> On Sun, Jan 25, 2009 at 11:08:14AM -0800, Ian Eure wrote:
>> If you enable flyspell-mode in a buffer, Emacs gets slow. Not
>> unbearably slow, but there's a distinct lag when you type. It seems  
>> to
>> get worse as the buffer gets larger.
>>
>> Other people have noticed:
>> http://www.nabble.com/CVS-version:-message-mode-%2B-flyspell-terribly-slow-td20666831.html
>
> That points to a thread in emacs-devel list,
>
> http://lists.gnu.org/archive/html/emacs-devel/2008-11/msg00859.html
> http://thread.gmane.org/gmane.emacs.devel/106090/focus=106118
>
>> The behavior doesn't happen on Emacs 22.
>
> Is the same problem described there? Does disabling the tool-bar  
> make this
> slowness disappear? Note that, after above threads, some  
> improvements were
> done on this at the end of November.
>

I'm not sure if it is or not. I don't notice any difference with the  
toolbar enabled or disabled. I keep it disabled by default.

It happens with the NS port. I haven't tried GTK+ / Xaw. It doesn't  
seem to happen if I run Emacs in a terminal. If I launch NS Emacs,  
then connect to it with emacsclient, I still get the problem. It  
happens whether the buffer is visible on the text frame, the GUI  
frame, or both.

It occurs when flyspell-mode is enabled in any buffer. The major mode  
doesn't matter.

It recently got mush worse, to the point where I must disable flyspell  
in erc-mode to maintain my sanity. I suspect it was the 2009-03-14  
commits to src/nsterm.m src/nsfont.m etc.

  - Ian