Further testing shows that this is purely an artifact of our thread use/system load... when run outside Fred, Sun takes about 20ms to do a modPow(), and Kaffe takes about 2ms. Under light load, Sun can take 200ms or so; under relatively heavy load, Sun takes 900-1400ms. This would appear to be mainly caused by our excessive usage of threads and its interaction with the kernel scheduler...
[CC'd to [EMAIL PROTECTED] because of borderline relevance, due to the figures on kaffe vs sun modPow()] On Sat, Mar 15, 2003 at 03:07:27AM +0000, Matthew Toseland wrote: > It looks like the dominating factor in the crypto in authorizeTime is > BigInteger.modPow() (a JVM-provided method, which really ought to be > fast...). I'm seeing an average time for modPow() of 1412ms (it seems to > be increasing...). With Sun 1.4. > > Now, with Kaffe, which uses libgmp, averages are closer to 59ms-75ms. > > I will run it on Kaffe overnight to see what happens. > > Possibilities: > > A) Fix remaining Kaffe problems (kaffe has monolithic GC, causing > longish delays from time to time which lock the whole VM, but there is a > kaffe derivative that uses Boehm incremental GC which could be merged; > kaffe seems to get longer lock times suggesting maybe its locking is very > heavy...), bundle Kaffe with Freenet (even on the Win32 version - this > should be possible, I believe there is a port). Grumble if running a Sun > JVM, but still run. > > B) Call out to an external, platform specific helper app if available > (grumble loudly if it isn't there). With times of a second or more, this > is probably still faster than using Sun's slow code. > > C) Any other suggestions? > > We really should do something about this is 0.5.2 - shaving 900ms off > average authorizeTime's/connectingTime's is not something to be ignored. > > BTW, the theory: Kaffe uses libgmp, which is very very fast. Sun uses > some apparently badly written in-house BigInteger code. > -- > Matthew Toseland > [EMAIL PROTECTED]/[EMAIL PROTECTED] > Full time freenet hacker. > http://freenetproject.org/ > Freenet Distribution Node (temporary) at > http://80-192-4-36.cable.ubr09.na.blueyonder.co.uk:8889/J3Q~LkZ7ezk/ > ICTHUS. -- Matthew Toseland [EMAIL PROTECTED]/[EMAIL PROTECTED] Full time freenet hacker. http://freenetproject.org/ Freenet Distribution Node (temporary) at http://80-192-4-36.cable.ubr09.na.blueyonder.co.uk:8889/nDBm5SExzKo/ ICTHUS.
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