FWIW, option 2 (hprof) seems like a no-show on u2b08: headius@headius-vbox-ubuntu:~/projects/redblack$ JAVA_HOME=~/jdk1.7.0_02/ ../jruby/bin/jruby -X+C -J-Xrunhprof:cpu=times bm1.rb 20 HPROF ERROR: Unknown constant [../../../src/share/demo/jvmti/java_crw_demo/java_crw_demo.c:693] [hprof_init.c:210] HPROF TERMINATED PROCESS
So I'm stuck with sampling. - Charlie On Fri, Oct 14, 2011 at 3:52 AM, Charles Oliver Nutter <head...@headius.com> wrote: > I'm looking to get back into JRuby + Indy work now that the heaviest > conferences are behind me. Part of this involves running larger > benchmarks where the hot spots may not be apparent at a glance. In > order to investigate performance on such benchmarks, I will want to do > some profiling. But what should I use? > > For really egregious problems, the sampling profiler (-Xprof) "sort > of" works. It's grossly inaccurate when there's no stand-out hotspot, > but if something is incredibly bad it usually shows it. So that's > option 1. > > There's -Xrunhprof:cpu=times, which is more accurate, but the impact > to running code is enormous, there's no way to filter out > uninteresting code (like JDK core), and I have no idea if it works > properly with indy (given that there's ongoing work to make JVMTI + > indy play nice). That's option 2. > > Are either of these options any good? What else do you recommend? > > - Charlie > _______________________________________________ mlvm-dev mailing list mlvm-dev@openjdk.java.net http://mail.openjdk.java.net/mailman/listinfo/mlvm-dev
