On 3/8/20 1:00 PM, Jonathan Neuschäfer wrote:
> Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@xxxxxxx>
> ---
> Documentation/core-api/atomic_ops.rst | 6 ++++++
> Documentation/core-api/refcount-vs-atomic.rst | 2 ++
> 2 files changed, 8 insertions(+)
>
> diff --git a/Documentation/core-api/atomic_ops.rst b/Documentation/core-api/atomic_ops.rst
> index 73033fc954ad..37a0ffe1a9f1 100644
> --- a/Documentation/core-api/atomic_ops.rst
> +++ b/Documentation/core-api/atomic_ops.rst
> @@ -392,6 +392,12 @@ be guaranteed that no other entity can be accessing the object::
> memory barriers in kfree_skb() that exposed the atomic_t memory barrier
> requirements quite clearly.
>
> +.. note::
> +
> + More recently, reference counts are implement using the
implemented
> + :ref:`refcount_t <refcount_t_vs_atomic_t>` type, which works like
> + atomic_t but protects against wraparound.
> +
> Given the above scheme, it must be the case that the obj->active
> update done by the obj list deletion be visible to other processors
> before the atomic counter decrement is performed.
--
~Randy
