On Friday 22 March 2002 11:27, Jukka Santala wrote:
On Thu, 21 Mar 2002, Dalibor Topic wrote:
Now you're confusing me, as well. As noted above, modifying code on one
platform can affect the performance of other platforms (or other code
paths) negatively, and I doubt most developers bother to benchmark even on
their own system after every little change that could've slowed things
down.
Hence it would be good idea to provide performance history graphs on
different platforms so that people can see that Aha, so something
committed on April the 1st turned the Gibbering test 50% slower on both
platforms X and Y, must have been the new gibber-collector I submitted...
I agree. I test the stuff I (re)implement for performance, but usually don't
bother testing the performance of small spec conformance fixes.
I would, for example, like to introduce a kaffe.util.param package in a not
too distant future. There is a lot of parameter checking code in the io
libraries, and I'd like to factor that out into the param package. The
package would contain just final classes with static methods. So your typical
method call to BufferedReader.read(buf, off, len) would call
kaffe.util.param.Buffer.check(buf, off, len) before it goes on with your read
request.
Since BufferedReader.read(char [], int, int) already checks its parameters,
this would in effect de-inline that code out of the read method. The
resulting performance penalty would be eliminated by a JIT compiler that can
inline final methods. But it would remain on platforms stuck with an
interpreter.
The interesting question to ask is: Is the adverse effect on performance on
those platforms big enough to kill this idea? I could only know if people
submitted benchmark results for those platforms, once the patch is out.
In general, if people run kaffe on benchmarks put the results on the
web, I assume that Jim will link to them. If people volunteer to do so
regularly,
That is somewhat what I had in mind. I'm bit reluctant to volunteer, as I
don't know how long I can contribute, but I should be able to put up
performance-tracking for AMD Duron and StrongARM at least. Intel platforms
should be relatively easy to come by.
Sounds great. I could offer results on a Cyrix Psomething+.
Do you have any specific benchmarks in mind?
dalibor topic
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