Re: gnus calling garbage collection?

[lee <lee@yun.yagibdah.de>]

Lars Magne Ingebrigtsen <larsi@gnus.org> writes:

> lee <lee@yun.yagibdah.de> writes:
>
>> is gnus calling the garbage collection function of emacs for every
>> message it writes when checking for new news? 
>
> Emacs collects garbage automatically whenever it feels like it.  Gnus
> doesn't call the gc functions explicitly.

Then the question is why emacs calls the garbage collection functions
for each message gnus is fetching out of the inbox despite
gc-cons-threshold is set to 4GB.

In trying to find a way to make fetching messages faster, I've been
reading some documentation: [1], [2] and [3]. About gc-cons-threshold,
they are saying in [3]:

,----
| The value of this variable is the number of bytes of storage that must
| be allocated for Lisp objects after one garbage collection in order to
| trigger another garbage collection.
`----

It seems somewhat unlikely that fetching one message from the inbox and
storing it somewhere in the nnml storage involves allocating (more than)
4GB of memory.

Is that a bug in emacs (GNU Emacs 23.3.1), or is 4GB too much? Hm, I'll
it with 1GB and see what happens ...

Yeah, it's doing a crazy amount of garbage collection. With
gc-cons-threshold set to 1GB, it seems to be doing considerably more
garbage collection than it does when I set it to 8GB.

Is there any good documentation about this? It seems that
gc-cons-percentage may also be important ...


[1]: http://www.emacswiki.org/emacs/GnusSpeed
[2]: http://www.gnu.org/software/emacs/manual/html_node/gnus/_005b9_002e2_005d.html
[3]: http://www.gnu.org/software/emacs/elisp/html_node/Garbage-Collection.html