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| author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2015-08-01 10:45:26 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2015-10-06 11:22:28 -0700 |
| commit | 27566139b6e2f6cfe273e8bb0e538d7616c2ea00 (patch) | |
| tree | 695fea5b3782a263fb681e4f6ace2aed29d33f1d /Documentation/memory-barriers.txt | |
| parent | 19a5ecde086a6a5287978b12ae948fa691b197b7 (diff) | |
| download | lwn-27566139b6e2f6cfe273e8bb0e538d7616c2ea00.tar.gz lwn-27566139b6e2f6cfe273e8bb0e538d7616c2ea00.zip | |
documentation: No acquire/release for RCU readers
Documentation/memory-barriers.txt calls out RCU as one of the sets
of primitives associated with ACQUIRE and RELEASE. There really
is an association in that rcu_assign_pointer() includes a RELEASE
operation, but a quick read can convince people that rcu_read_lock() and
rcu_read_unlock() have ACQUIRE and RELEASE semantics, which they do not.
This commit therefore removes RCU from this list in order to avoid
this confusion.
Reported-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Diffstat (limited to 'Documentation/memory-barriers.txt')
| -rw-r--r-- | Documentation/memory-barriers.txt | 1 |
1 files changed, 0 insertions, 1 deletions
diff --git a/Documentation/memory-barriers.txt b/Documentation/memory-barriers.txt index 2ba8461b0631..d336e4d42029 100644 --- a/Documentation/memory-barriers.txt +++ b/Documentation/memory-barriers.txt @@ -1789,7 +1789,6 @@ The Linux kernel has a number of locking constructs: (*) mutexes (*) semaphores (*) R/W semaphores - (*) RCU In all cases there are variants on "ACQUIRE" operations and "RELEASE" operations for each construct. These operations all imply certain barriers: |