[armedbear-devel] Profiling ABCL exception handling

[Joel Borggrén-Franck]

On Sat, Nov 6, 2010 at 7:24 PM, Erik Huelsmann <ehuels at gmail.com> wrote:
> Yesterday, I started playing around with JRockit's MissionControl
> tool, now that we run on JRockit.
>

> Running an exception profile on Maxima running its test suite shows
> lots of non-local transfer of control exceptions: Return, Go and
> Throw: during a run of ca 10 minutes, I'm finding 5.5 million
> exceptions being thrown which - as MissionControl calculated for me -
> should mean an average of little over 12k/s. I guess that's kind of
> expected with our strategy for non-local transfers of control.

To put this into context we (developers at JRockit) expect ~1000
exceptions / core / sec from a "typical" Weblogic app. We define this
as a bit much but not terribly excessive.

My guess is that between the horrible support for fixnums (and the
really slow bignums) in Java and the order of magnitude higher
exception count this will dominate your performance.

cheers
/J