lgpl-relicensing.md

   1 <!--
   2 SPDX-FileCopyrightText: 2009 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   3
   4 SPDX-License-Identifier: CC-BY-4.0
   5 -->
   6
   7 # Userspace-RCU LGPL 2.1+ re-licensing
   8
   9 Mathieu Desnoyers
  10 May 13th, 2009
  11
  12 IBM Corporation allowed LGPLv2.1+ licensing of their contribution to the
  13 userspace RCU library in a patch submitted on May 8, 2009 from Paul E.
  14 McKenney and reviewed by Steven L. Bennett:
  15
  16     https://lists.lttng.org/pipermail/lttng-dev/2009-May/012835.html
  17
  18 I (Mathieu Desnoyers) re-implemented ACCESS_ONCE(), likely(), unlikely() and
  19 barrier() from scratch without reference to the original code.
  20
  21     commit id : 2dc5fa0f7cfbfb0a64a7a67b39626650e863f16a
  22
  23 Bert Wesarg <bert.wesarg@googlemail.com> approved LGPL re-licensing of his
  24 patch in an email dated May 13, 2009 :
  25
  26     http://lkml.org/lkml/2009/5/13/16
  27
  28 xchg() primitives has been rewritten from a MIT-licensed cmpxchg for Intel
  29 and powerpc. They are MIT-licensed and therefore usable in LGPL code.
  30 This cmpxchg code was obtained from the atomic_ops project:
  31
  32     http://www.hpl.hp.com/research/linux/atomic_ops/
  33
  34 I (Mathieu Desnoyers) wrote the remainder of the code.
  35
  36 The license for the library files in this project was therefore changed to
  37 LGPLv2.1 on May 13, 2009, as detailed in LICENSE.