[PATCH rcu 06/15] doc: Update rcu.rst

From: Paul E. McKenney
Date: Wed Jan 04 2023 - 19:10:32 EST


This commit provides a couple of updates based on the inexorable passage
of time.

Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
---
Documentation/RCU/rcu.rst | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Documentation/RCU/rcu.rst b/Documentation/RCU/rcu.rst
index 3cfe01ba9a494..381cb86f657d8 100644
--- a/Documentation/RCU/rcu.rst
+++ b/Documentation/RCU/rcu.rst
@@ -77,12 +77,13 @@ Frequently Asked Questions
search for the string "Patent" in Documentation/RCU/RTFP.txt to find them.
Of these, one was allowed to lapse by the assignee, and the
others have been contributed to the Linux kernel under GPL.
+ Many (but not all) have long since expired.
There are now also LGPL implementations of user-level RCU
available (https://liburcu.org/).

- I hear that RCU needs work in order to support realtime kernels?

- Realtime-friendly RCU can be enabled via the CONFIG_PREEMPT_RCU
+ Realtime-friendly RCU are enabled via the CONFIG_PREEMPTION
kernel configuration parameter.

- Where can I find more information on RCU?
--
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