+Bert Wesarg <bert.wesarg@googlemail.com> approved LGPL relicensing of his
+patch in an email dated May 13, 2009 :
+
+ http://lkml.org/lkml/2009/5/13/16
+
+xchg() primitives has been rewritten from a MIT-licensed cmpxchg for Intel
+and powerpc. They are MIT-licensed and therefore usable in LGPL code.
+This cmpxchg code was obtained from the atomic_ops project:
+
+ http://www.hpl.hp.com/research/linux/atomic_ops/
+
+I (Mathieu Desnoyers) wrote the remainder of the code.
+
+The license for the library files in this project was therefore changed to
+LGPLv2.1 on May 13, 2009, as detailed in LICENSE.