Re: [PATCH] XArray: minor documentation improvements

From: Darrick J. Wong
Date: Wed Oct 09 2024 - 16:48:32 EST


On Wed, Oct 09, 2024 at 03:36:03PM -0400, Tamir Duberstein wrote:
> - Replace "they" with "you" where "you" is used in the preceding
> sentence fragment.
> - Use "erasing" rather than "storing `NULL`" when describing multi-index
> entries. Split this into a separate sentence.
> - Add "call" parentheses on "xa_store" for consistency and
> linkification.
>
> Signed-off-by: Tamir Duberstein <tamird@xxxxxxxxx>
> ---
> Documentation/core-api/xarray.rst | 10 +++++-----
> 1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/Documentation/core-api/xarray.rst b/Documentation/core-api/xarray.rst
> index 77e0ece2b1d6..d79d4e4ceff6 100644
> --- a/Documentation/core-api/xarray.rst
> +++ b/Documentation/core-api/xarray.rst
> @@ -42,8 +42,8 @@ call xa_tag_pointer() to create an entry with a tag, xa_untag_pointer()
> to turn a tagged entry back into an untagged pointer and xa_pointer_tag()
> to retrieve the tag of an entry. Tagged pointers use the same bits that
> are used to distinguish value entries from normal pointers, so you must
> -decide whether they want to store value entries or tagged pointers in
> -any particular XArray.
> +decide whether use want to store value entries or tagged pointers in any

"...so you must decide if *you* want to store value entries or..."

> +particular XArray.
>
> The XArray does not support storing IS_ERR() pointers as some
> conflict with value entries or internal entries.
> @@ -52,8 +52,8 @@ An unusual feature of the XArray is the ability to create entries which
> occupy a range of indices. Once stored to, looking up any index in
> the range will return the same entry as looking up any other index in
> the range. Storing to any index will store to all of them. Multi-index
> -entries can be explicitly split into smaller entries, or storing ``NULL``
> -into any entry will cause the XArray to forget about the range.
> +entries can be explicitly split into smaller entries. Erasing any entry
> +will cause the XArray to forget about the range.

n00b question: is xa_store(..., NULL) the same as xa_erase?

If it is, then should the documentation mention that xa_store(NULL) is
the same as xa_erase, and that both of these operations will cause the
xarray to forget about that range?

--D

> Normal API
> ==========
> @@ -64,7 +64,7 @@ allocated ones. A freshly-initialised XArray contains a ``NULL``
> pointer at every index.
>
> You can then set entries using xa_store() and get entries
> -using xa_load(). xa_store will overwrite any entry with the
> +using xa_load(). xa_store() will overwrite any entry with the
> new entry and return the previous entry stored at that index. You can
> use xa_erase() instead of calling xa_store() with a
> ``NULL`` entry. There is no difference between an entry that has never
> --
> 2.47.0
>
>