On Mon, Apr 17, 2023 at 07:04:50PM +0000, SeongJae Park wrote:
> The SLAB_TYPESAFE_BY_RCU example code snippet uses a single RCU
> read-side critical section for retries.
> 'Documentation/RCU/rculist_nulls.rst' has similar example code snippet,
> and commit da82af04352b ("doc: Update and wordsmith rculist_nulls.rst")
> broke it up. Apply the change to SLAB_TYPESAFE_BY_RCU example code
> snippet, too.
>
> Signed-off-by: SeongJae Park <sj@xxxxxxxxxx>
Reviewed-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
> ---
> include/linux/slab.h | 8 +++++---
> 1 file changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/include/linux/slab.h b/include/linux/slab.h
> index b18e56c6f06c..6acf1b7c6551 100644
> --- a/include/linux/slab.h
> +++ b/include/linux/slab.h
> @@ -53,16 +53,18 @@
> * stays valid, the trick to using this is relying on an independent
> * object validation pass. Something like:
> *
> + * begin:
> * rcu_read_lock();
> - * again:
> * obj = lockless_lookup(key);
> * if (obj) {
> * if (!try_get_ref(obj)) // might fail for free objects
> - * goto again;
> + * rcu_read_unlock();
> + * goto begin;
> *
> * if (obj->key != key) { // not the object we expected
> * put_ref(obj);
> - * goto again;
> + * rcu_read_unlock();
> + * goto begin;
> * }
> * }
> * rcu_read_unlock();
> --
> 2.25.1
>
