Gnus & garbage collection

[Jesper Harder <harder@ifa.au.dk>]

Hi!

I tried to set `garbage-collection-messages' to t, and I noticed that
Emacs collects garbage like crazy when performing some Gnus actions.

Here are some timing results that show how it affects performance when
entering a large summary buffer and a server buffer.

This is with the default value of `gc-cons-threshold' (400,000 in Emacs):

  Function Name            Call Count  Elapsed Time 
  =======================  ==========  ============ 
  gnus-topic-select-group  1           94.222058    
  gnus-server-read-server  1           50.094491    

And this is with `gc-cons-threshold' increased to 4,000,000:

  Function Name            Call Count  Elapsed Time 
  =======================  ==========  ============ 
  gnus-topic-select-group  1           54.852086
  gnus-server-read-server  1           27.06671

So, with the default value nearly half of the time is spent in the
garbage collector.

I don't know if it's worth doing something about it -- maybe parts of
the code that are likely to generate large amounts of lisp data should
have `gc-cons-threshold' increased, or maybe people should just increase
it themself if they want a faster Gnus (and memory permits it).

-- 
Cheers,
Jesper Harder