Performance [LWN.net]

Performance

Posted Aug 7, 2003 11:14 UTC (Thu) by ag (subscriber, #13761)
In reply to: Performance by walles
Parent article: Natively compiled Eclipse

This will give you some idea. The Eclipse java compiler can be extracted from Eclipse in order to produce a stand-alone command line tool (ecj).

This is a typical native ecj build (of rhino, in this example). I used the
-repeat option to try to factor out any "fast start" advantage of the native
executable.

$ time find ./ -name \*.java | xargs ecj -bootclasspath /home/green/tools/FSF/HEAD/i/share/java/libgcj-3.4 .jar -repeat 5 -log out.log
Repetition 1/5
Repetition 2/5
Repetition 3/5
Repetition 4/5
Repetition 5/5

real 0m7.136s
user 0m6.660s
sys 0m0.400s

Here's the same compiler being run with IBM's jre...

$ time find ./ -name \*.java | xargs java org.eclipse.jdt.internal.compiler.batch.Main -bootclasspath /home/green/tools/FSF/HEAD/i/share/java/libgcj-3.4 .jar -repeat 5 -log out.log
Repetition 1/5
Repetition 2/5
Repetition 3/5
Repetition 4/5
Repetition 5/5

real 0m20.863s
user 0m19.880s
sys 0m0.710s

An easy way to build ecj for yourself is to get it from here: http://sources.redhat.com/rhug

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Performance

Posted Aug 9, 2003 14:23 UTC (Sat) by walles (subscriber, #954) [Link]

You start up the JVM five times. As I said, gcj's startup time should be much better than that of any JVM, and you just demonstrated that.

This doesn't say anything about the runtime performance.

Oops

Posted Aug 9, 2003 14:57 UTC (Sat) by walles (subscriber, #954) [Link]

Sorry, should've read what you wrote in its entirety instead of just brushing you off. Could you try running the same thing with -repeat 1000 instead?

Considering Eclipse is probably run for hours at a time, a seven second benchmark (in the gcj case) may not do IBM's VM justice.

Other than the short time it ran, I'd say that's a reasonable benchmark.