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| -rw-r--r-- | Documentation/memory-barriers.txt | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/Documentation/memory-barriers.txt b/Documentation/memory-barriers.txt index 8b11e54238bf..147ae8ec836f 100644 --- a/Documentation/memory-barriers.txt +++ b/Documentation/memory-barriers.txt @@ -498,6 +498,11 @@ And a couple of implicit varieties: This means that ACQUIRE acts as a minimal "acquire" operation and RELEASE acts as a minimal "release" operation. +A subset of the atomic operations described in atomic_ops.txt have ACQUIRE +and RELEASE variants in addition to fully-ordered and relaxed (no barrier +semantics) definitions. For compound atomics performing both a load and a +store, ACQUIRE semantics apply only to the load and RELEASE semantics apply +only to the store portion of the operation. Memory barriers are only required where there's a possibility of interaction between two CPUs or between a CPU and a device. If it can be guaranteed that |