Speed difference in Gnus
Stephen J. Turnbull
stephen at xemacs.org
Fri Oct 21 12:58:44 EDT 2005
>>>>> "Uwe" == Uwe Brauer <oub at mat.ucm.es> writes:
Uwe> I just want to point that may be you have not considered all
Uwe> possible reasons for the speed loss of Xemacs against GNU.
Sure. I can name a number of them. Contributions on any of them
would be welcome.
(1) Packages vs. monolithic distribution. We do a _lot_ more stats.
I suspect this has regressed somewhat, too.
(2) Portable dumper. I doubt this is _big_, but certainly it has to
be slower than unexec.
(1) The extent issues we've been discussing.
(2) I suspect redisplay is slowed dramatically by code kluged in to
ensure correct display of the native widgets. I know for sure that in
Xft most everything gets displayed twice on every redisplay.
(3) Regexp issues. It's not hard to write regexps that behave badly
in loops, and XEmacs's regexp implementation has had problems with
(4) Algorithms. I suspect that for most packages GNU has a decided
advantage in terms of the amount of developer time that goes into
optimizing for them, and there's a strong bias toward designing things
that are efficient for GNU, and then hacking in XEmacs support later.
Even for stuff at the C level, this is often a problem. Naive ports
of stuff like the syntax table property have caused huge performance
School of Systems and Information Engineering http://turnbull.sk.tsukuba.ac.jp
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