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Diffstat (limited to 'Documentation/atomic_ops.txt')
| -rw-r--r-- | Documentation/atomic_ops.txt | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/Documentation/atomic_ops.txt b/Documentation/atomic_ops.txt index b19fc34ef..c9d1cacb4 100644 --- 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: |