On Thu, Feb 17, 2011 at 10:44:14PM +0700, C. Bergstr?m wrote: > fwiw some people still *really* care about emacs performance even on > modern hw. We (PathScale) have a few vocal users and plan to spin some > cycles to speed it up a bit.
[Well as long as we're almost totally off topic...] As a constant (X and Gnu) Emacs user for the last 11 years, I can say that only rarely has its serial speed ever been a problem, and then usually solved by Don't Do That. E.g., turn off font-lock-mode in any shell buffers that might receive many thousands of lines of output; don't try to read massive mail folders in VM, use mutt under screen instead. Emacs's glaring weakness is its pervasive single-threadedness. Its whole UI will just lock up completely in many cases, with the cpu pegged at 100%, when it can't keep up with output from some child process. E.g., R spitting out some sort of absurdly large backtrace, which ess-mode tries to parse or markup in some fashion. In those cases, the only solution is generally to switch to a different shell and kill the child process; then Emacs will recover. Emacs needs more concurrency. Although ironically, continuing to run on just 1 cpu core would be adequate; it's its lack of UI responsiveness under stress that's just stupid. Firefox seems to have been gradually getting better at that, although version 3.6.13 is still far from perfect. AFAICT Emacs hasn't made any similar progress, but I admit I haven't looked. It's good enough in other ways that I merely put up with its few grating flaws. Although now that I think of it, since the slow output-parsing stuff in Emacs is probably implemented by running one or more regular expression matches on every single line, it might be helpful to retrofit an efficient linear time regexp engine like Russell Cox's RE2: http://swtch.com/~rsc/regexp/regexp3.html "Regular Expression Matching in the Wild", by Russ Cox, March 2010 http://code.google.com/p/re2/ http://swtch.com/~rsc/regexp/ http://sljit.sourceforge.net/regex_perf.html Performance comparison of regular expression engines -- Andrew Piskorski <a...@piskorski.com> http://www.piskorski.com/ _______________________________________________ Beowulf mailing list, Beowulf@beowulf.org sponsored by Penguin Computing To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
