Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...

[karo-tx-linux.git] / Documentation / atomic_ops.txt

diff --git a/Documentation/atomic_ops.txt b/Documentation/atomic_ops.txt
index b19fc34efdb17921af43bda0000b13dc82640451..c9d1cacb439590a02dbfb1282cbe0d3abe3a9b0d 100644 (file)
--- a/Documentation/atomic_ops.txt
+++ b/Documentation/atomic_ops.txt
@@ -542,6 +542,10 @@ The routines xchg() and cmpxchg() must provide the same exact
 memory-barrier semantics as the atomic and bit operations returning
 values.
 
+Note: If someone wants to use xchg(), cmpxchg() and their variants,
+linux/atomic.h should be included rather than asm/cmpxchg.h, unless
+the code is in arch/* and can take care of itself.
+
 Spinlocks and rwlocks have memory barrier expectations as well.
 The rule to follow is simple: