Subject: Re: inhibiting GC From: Erik Naggum <erik@naggum.no> Date: 1999/06/04 Newsgroups: comp.lang.lisp Message-ID: <3137457161009599@naggum.no> * Tim Bradshaw <tfb@tfeb.org> | I once turned this thing on and left it turned on for several days in the | Emacs I was using to do all my work, including several largish elisp | packages like VM and gnus and probably psgml &c. The results were that | it spent about 1-2% of its time in GC, and about 60-80% in updating the | screen. Like Erik says, Emacs' GC is rudimentary, but it was so far from | the critical path in terms of performance as to be totally irrelevant. | So much for mythology. there are several interesting aspects to this: (1) people see that something is happening when the screen updates, (2) people see a pause when the "Garbage collecting..." message lights up, and (3) they thought Emacs got a lot faster when that message was removed (at my request). if it moves slowly, humans can deal well with it. if it moves in jerks and spasms, humans get nervous. the overall impression of "smoothness" is very important to user perception of speed; any break in smoothness is then taken as a serious flaw. we see the same thing in many areas: people had no problems dealing with 110 baud ttys 20 years ago, and if the information trickles in, people can still deal with very slow lines (witness the World Wide Wait, and how people happily wait for images of text to crawl across the line at the rate of 1 character a second), but if you give somebody a 56kbps line and it goes from 56 kbps to 110 bps and back at random intervals, you can drive people literally insane, and that's precisely what the WWW does to congested links. still, it's the greatest thing since sliced bread. all we have to do now is make the WWW better than sex for the dumb people who click on the advertising, so they won't procreate! ahem, I digress. #:Erik -- @1999-07-22T00:37:33Z -- pi billion seconds since the turn of the century