Re: request: make-frame-visible hook

[Eli Zaretskii]

> From: address@hidden (Kim F. Storm)
> Date: Sat, 21 Feb 2009 03:11:36 +0100
> Cc: address@hidden
> 
> Miles Bader <address@hidden> writes:
> 
> > Lynbech Christian <address@hidden> writes:
> >> Alternatively you can consider using post-command-hook, this is run all
> >> the time and this particular problem should not pose a performance
> >> problem.
> >
> > Using post-command-hook _will_ pose a performance problem if everybody
> > and their dog gets in the habit of using it... 
> 
> I know people are repeating this claim again and again as "gospel truth".
> 
> However, I strongly doubt this is really true in practice.
> The amount of lisp code executed in the post-command-hook is not nearly
> comparable to the amount of work done in redisplay for every (non-trivial)
> keypress...  
> 
> E.g. just hitting RET performs - I would guess - 1000 times the code anybody
> has every put into the post-command-hook...

Of course, this depends on what is put into post-command-hook.  For
example, doing spell-check there, which involves interaction with a
subprocess, _does_ give you a performance hit that is quite
noticeable.