Comment 7 for bug 520715

OK, let's try to summarize...

Facts, on --enable-pthread vs --disable-pthread:
- There's a noticeable performance gain with --disable-pthread, at least with some benchmarks.
- Consequences of switching to --disable-pthread are unclear. Linking a non-pthread ruby with a pthread tk doesn't work (so that breaks Ruby/Tk), and other libs might (are likely?) to break as well.
- Ruby has been built with --enable-pthread for ages on Debian and Ubuntu (at least since Dapper).
- You claim that Red Hat doesn't use --enable-pthread, but you are wrong according to http://cvs.fedoraproject.org/viewvc/F-12/ruby/ruby.spec?r1=1.74&r2=1.75&
- Building with --disable-pthread is just a work-around for this issue. And since we don't know what the real issue is yet, it might just hide the issue a bit deeper.

Given the above, it is not a viable solution to build with --disable-pthread.

On the issue itself:
you apparently have a test case, since you were able to pinpoint a specific SVN commit? Could you make it public?