Comment 6 for bug 1085342

Most distributions (Fedora, Debian, openSUSE) revert this patch.

Quoting an email from Jeff below
http://sourceware.org/ml/libc-alpha/2012-01/msg00002.html

An FYI, this patch:

commit c5a0802a682dba23f92d47f0f99775aebfbe2539
Author: Andreas Schwab <email address hidden>
Date: Mon Nov 28 13:38:19 2011 +0100

    Handle EAGAIN from FUTEX_WAIT_REQUEUE_PI

Has been reported as causing numerous problems in Fedora & Debian. I
don't think anyone has done any serious analysis of the issue, but the
patch has been pulled from both distributions because of the
instability it's introduced.

https://bugzilla.redhat.com/show_bug.cgi?id=769421
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=651899

It might be worth your time to dig further into the change or pull it
from 2.15 pending a deeper investigation.