From: Justin Collins <collinsj@...>
Date: 2006-07-29T02:12:28+09:00
Subject: Re: Better profiling for ruby?

Daniel Martin wrote:
> So the recent performance threads have all repeated the wisdom
> "profile first" in various forms, and various ways.
>
> I have a problem with this.  I can't read the output of the ruby
> profiler and get meaningful insights on my script.
>
> Invariably, the profiler will tell me that almost all of my time is
> being sucked up in Range#each or Integer#upto.  In other words, the
> profiler is telling me that my time is being sucked up into some loop
> somewhere.  Thanks a bunch; any idea which of the twenty loops in my
> program that is?
>
> Over in the perl world, my favorite profiler has been
> Devel::SmallProf.  I've found there's nothing to compare with it for
> producing those surprising "so *thats* where all my time has been
> going" moments.  It does this by giving me an easy feedback on which
> lines of my program suck up the most time (both in terms of that line
> directly and, if the line contains a sub call, the lines it calls).
> I've found this line-number-based approach to profiling incredibly
> helpful, much more helpful than traditional method-based summaries.
>
> In fact, I found this approach so useful that I even implemented it
> for java (http://perlmonks.org/?node_id=381641).  This has been a real
> blessing in my current job, allowing me to focus performance tuning at
> a level that seems natural.
>
> Now, is there any way to get this kind of information for ruby?  I'd
> like to be able to look at the output of a profiler and get some
> information useful to making the script faster out of it.  Barring
> that, is there somewhere on the web a worked example of taking a
> initial (nontrivial) ruby script, working with the profiler, and
> ending up with a faster script

ruby-prof is pretty neat. I haven't used it a lot, but I feel it's a bit 
more informative (and much faster) than the standard Ruby profiler.

http://rubyforge.org/projects/ruby-prof/

-Justin