path: root/Documentation/RCU
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authorWill Deacon <>2019-11-07 14:36:37 +0000
committerWill Deacon <>2020-07-21 10:50:36 +0100
commit8ca924aeb4f28e5bf552707e8ecbe105c4f17c7b (patch)
tree0dd13b4936f3f962fab7544260be7d68133eb5ad /Documentation/RCU
parent93fab07c22930c9ac4f01212fd92913c9a812f9f (diff)
Documentation/barriers: Remove references to [smp_]read_barrier_depends()
The [smp_]read_barrier_depends() barrier macros no longer exist as part of the Linux memory model, so remove all references to them from the Documentation/ directory. Although this is fairly mechanical on the whole, we drop the "CACHE COHERENCY" section entirely from 'memory-barriers.txt' as it doesn't make any sense now that the dependency barriers have been removed. Acked-by: Peter Zijlstra (Intel) <> Acked-by: Paul E. McKenney <> Signed-off-by: Will Deacon <>
Diffstat (limited to 'Documentation/RCU')
1 files changed, 1 insertions, 1 deletions
diff --git a/Documentation/RCU/Design/Requirements/Requirements.rst b/Documentation/RCU/Design/Requirements/Requirements.rst
index 75b8ca007a11..50d5c43c48b0 100644
--- a/Documentation/RCU/Design/Requirements/Requirements.rst
+++ b/Documentation/RCU/Design/Requirements/Requirements.rst
@@ -463,7 +463,7 @@ again without disrupting RCU readers.
This guarantee was only partially premeditated. DYNIX/ptx used an
explicit memory barrier for publication, but had nothing resembling
``rcu_dereference()`` for subscription, nor did it have anything
-resembling the ``smp_read_barrier_depends()`` that was later subsumed
+resembling the dependency-ordering barrier that was later subsumed
into ``rcu_dereference()`` and later still into ``READ_ONCE()``. The
need for these operations made itself known quite suddenly at a
late-1990s meeting with the DEC Alpha architects, back in the days when