Re: Redisplay: NS port, high CPU load

[David Reitter]

On Jun 14, 2016, at 3:16 AM, Eli Zaretskii <address@hidden> wrote:

> David said that it didn't happen in "emacs -Q", but did happen in his
> normal setup, and AFAIU intended to come up with a recipe.

OK, I looked into this.  I don’t have time right now for a recipe, but what’s 
happening is that I’m loading (my version of) tabbar.el, which does this:

(add-hook 'first-change-hook 'tabbar-window-update-tabsets-when-idle)

Only when first-change-hook is set are those extraneous toolbar refreshes made. 
 The tabbar-window-update function at some point calls  (force-window-update 
(window-buffer)), which may be what triggers the toolbar refresh.

So, I think that we should think about disabling hooks such as 
buffer-list-update-hook, first-change-hook, kill-buffer-hook, for temporary 
buffers.  In my view it just does not make sense to run the hooks for temporary 
buffers in any sensible scenario.

I also think that this change might affect some modes, if only by triggering 
bugs.  Therefore I would argue that the change to ucs-normalize is the minimal 
change to fix my bug, and a good housekeeping change in general.