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| -rw-r--r-- | Documentation/core-api/atomic_ops.rst | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/Documentation/core-api/atomic_ops.rst b/Documentation/core-api/atomic_ops.rst index 4ea4af71e68a..2e7165f86f55 100644 --- a/Documentation/core-api/atomic_ops.rst +++ b/Documentation/core-api/atomic_ops.rst @@ -466,10 +466,12 @@ Like the above, except that these routines return a boolean which indicates whether the changed bit was set _BEFORE_ the atomic bit operation. -WARNING! It is incredibly important that the value be a boolean, -ie. "0" or "1". Do not try to be fancy and save a few instructions by -declaring the above to return "long" and just returning something like -"old_val & mask" because that will not work. + +.. warning:: + It is incredibly important that the value be a boolean, ie. "0" or "1". + Do not try to be fancy and save a few instructions by declaring the + above to return "long" and just returning something like "old_val & + mask" because that will not work. For one thing, this return value gets truncated to int in many code paths using these interfaces, so on 64-bit if the bit is set in the |