Thanks Vladimir, that's interesting (particularly about Rubinius). Question: Is this the same issue as reported here? http://rubyforge.org/tracker/index.php?func=detail&aid=15425&group_id=426&atid=1698 and discussed here: http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-core/15325 (see also http://svn.ruby-lang.org/cgi-bin/viewvc.cgi?view=rev&revision=10689 ) I found that undoing those changes to parse.y fixes the leak. But that change was made to fix a problem which I would now re-introduce I presume. Unfortunately I don't know what that original problem was apart from it was fixed by preventing local_tbl from being garbage collected as per the cvs comment. Can anyone shed any light? - Stephen On Sun, Mar 23, 2008 at 9:33 PM, Vladimir Sizikov <vsizikov / gmail.com> wrote: > Hi Stephen, > > Out of curiosity, I tried the test case, and here are my results: > > MRI 1.8.6 pl 111, memory grows with 80Mb/sec rate (!!!) > Latest MRI 1.8 branch: memory grows with 80Mb/sec rate too > MRI 1.9 - memory doesn't grow > JRuby 1.1RC2 - memory doesn't grow > Rubinius - memory grows at 500Kb/sec > > Thanks, > --Vladimir > >