Great! you have a profiler, use that. Find the hotspots, use YourKit to find where the .cons is being called from, find things to optimize, and go from there. This is exactly the same process I would use any optimizations I attempted.
Timothy On Wed, Oct 23, 2013 at 6:09 AM, Paul Butcher <p...@paulbutcher.com> wrote: > On 23 Oct 2013, at 12:44, Timothy Baldridge <tbaldri...@gmail.com> wrote: > > That being said, the #1 rule of benchmarking with lein is don't benchmark > with lein. The JVM lein spins up has a different set of goals (namely > startup time). The best way to benchmark is to run the test several > thousand times, from a jar created with lein uberjar. > > > I'm well aware of the issues associated with micro-benchmarking on the > JVM. Bear in mind that what I'm doing isn't micro-benchmarking. I have a > Scala program that runs in 2.5 minutes, which when re-implemented in > Clojure doesn't finish after being run overnight. I.e. the Clojure is (at > least) 2 orders of magnitude slower than the Scala. > > I'd love to be able to run it just once - running it thousands of times > with its current performance would require *years*. > > I've now got it recompiled as an uberjar and I'm running it with 12G RAM > (-Xms12G -Xmx12G). So far, it's been running for 12 minutes (i.e. 6x longer > than the Scala version takes to complete) and YourKit shows me that it's > used less than 300MB RAM (i.e. the vast majority of the 12G is unused). > > YourKit also shows me that it's still the case that it's spending 99% of > its time in PersistentHashSet.cons. > > I completely understand that playing around with pre-compilation and JVM > settings will make a difference to the observed performance. But not two > orders of magnitude difference, surely? > > It strikes me that there's clearly something that I'm missing in the > Clojure implementation that's making a dramatic difference to performance. > I'd love some help determining what that something is. > > -- > paul.butcher->msgCount++ > > Snetterton, Castle Combe, Cadwell Park... > Who says I have a one track mind? > > http://www.paulbutcher.com/ > LinkedIn: http://www.linkedin.com/in/paulbutcher > MSN: p...@paulbutcher.com > AIM: paulrabutcher > Skype: paulrabutcher > > -- > -- > You received this message because you are subscribed to the Google > Groups "Clojure" group. > To post to this group, send email to clojure@googlegroups.com > Note that posts from new members are moderated - please be patient with > your first post. > To unsubscribe from this group, send email to > clojure+unsubscr...@googlegroups.com > For more options, visit this group at > http://groups.google.com/group/clojure?hl=en > --- > You received this message because you are subscribed to the Google Groups > "Clojure" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to clojure+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/groups/opt_out. > -- “One of the main causes of the fall of the Roman Empire was that–lacking zero–they had no way to indicate successful termination of their C programs.” (Robert Firth) -- -- You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en --- You received this message because you are subscribed to the Google Groups "Clojure" group. To unsubscribe from this group and stop receiving emails from it, send an email to clojure+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
