diff options
author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2015-09-17 18:18:32 +0300 |
---|---|---|
committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2015-10-06 21:22:57 +0300 |
commit | ad2ad5d31f90fc6fb269e9be244224cecfc8b400 (patch) | |
tree | 514da7f8d0ff06b41f1e0c553c10188ce9cc5814 /Documentation/memory-barriers.txt | |
parent | b672adf8cfb822781ab904343e5de0297ee117ed (diff) | |
download | linux-ad2ad5d31f90fc6fb269e9be244224cecfc8b400.tar.xz |
documentation: Add lockless_dereference()
The recently added lockless_dereference() macro is not present in the
Documentation/ directory, so this commit fixes that.
Reported-by: Dmitry Vyukov <dvyukov@google.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 | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/Documentation/memory-barriers.txt b/Documentation/memory-barriers.txt index d336e4d42029..8e7cf9ad3db1 100644 --- a/Documentation/memory-barriers.txt +++ b/Documentation/memory-barriers.txt @@ -1710,6 +1710,17 @@ There are some more advanced barrier functions: operations" subsection for information on where to use these. + (*) lockless_dereference(); + This can be thought of as a pointer-fetch wrapper around the + smp_read_barrier_depends() data-dependency barrier. + + This is also similar to rcu_dereference(), but in cases where + object lifetime is handled by some mechanism other than RCU, for + example, when the objects removed only when the system goes down. + In addition, lockless_dereference() is used in some data structures + that can be used both with and without RCU. + + (*) dma_wmb(); (*) dma_rmb(); |