Performance of Java on FBSD vs. others...
freebsd at spatula.net
Mon Dec 18 09:42:22 PST 2006
On Mon, 18 Dec 2006, Achilleas Mantzios wrote:
> Raising such an important issue as the current thread,
> i think deserves something more than complete silence.
The silence is probably because a lot of us have jobs and lives to lead
and can't spend our every waking moment focused on Java performance on
FreeBSD. Few people, if any, are getting paid to work on this. It isn't
rational to set high expectations for responses. I suspect performance
comes second to functional problems and bugs as well.
I think I'd be more comfortable seeing the results of some *comprehensive*
benchmarks, rather than just one case that seems to perform better on one
platform than another. If you put some thought into it, I wager you could
always find some test case that works well on one architecture and poorly
I'd also like to see it run on a *STABLE* branch of FreeBSD, rather than
on CURRENT, since CURRENT is likely to be filled with all manner of
debugging noise and so-on. It should also be run with libthr as the
threading library, as the consensus seems to be that this provides better
performance than libpthread (libkse).
Wherever possible, it is important to compare apples to apples as well.
So if the libraries and binaries are stripped on Linux, they need to be
stripped on FreeBSD. If it's not a debug build on Linux, it needs not to
be a debug build on FreeBSD. JVM garbage collection and memory allocation
strategies need to be the same, *and they might not be by default*
depending on how Java was compiled.
There are so many problems with the "benchmark" presented that I don't
believe it can be used as the basis for troubleshooting performance
problems. We need to see a benchmark that does comprehensive testing of
performance for a variety of Java functions on the same hardware with the
same internal configuration. Maybe SPECjbb2005 or CaffeineMark 3.0?
Whatever benchmark is used should be run with profiling switched on, so if
there *is* a difference in timings, one can look at the profile data and
see where the additional time is being spent. It's also important to run
the benchmarks with plenty of memory allocated to take resource
constraints out of the picture. I'd go so far as to set the minimum and
maximum heap sizes to the same value to get all of the memory allocated
Without a clear problem definition and a methodical strategy for
investigating any actual or perceived performance differences, you're
taking a vague assertion and stabbing around in the dark trying to change
When you're a kid, they tell you it's all grow up, get a job, get married,
get a house, have a kid, and that's it. No, the truth is the world is so
much stranger than that. It's so much darker, and so much madder.
And so much better.
-- Elton, Doctor Who, "Love and Monsters"
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