Mathieu Desnoyers
May 13th, 2009

IBM Corporation allowed LGPLv2.1+ licensing of their contribution to the
userspace RCU library.

ACCESS_ONCE(), likely(), unlikely() and barrier() are considered trivial enough
that copyright does not apply to them. I (Mathieu Desnoyers) re-typed them from
scratch in a mail client just to prove it.

Bert Wesarg <bert.wesarg@googlemail.com> approved LGPL relicensing of his patch.

xchg() primitives has been rewritten from a MIT-licensed cmpxchg for Intel and
powerpc. They are MIT-licensed and therefore usable in LGPL code.

I am therefore permitted to relicense the userspace RCU library as LGPLv2.1.