Re: [PATCH v2] Documentation/mm: Add information about kmap_local_folio()

From: Randy Dunlap
Date: Sat Jul 01 2023 - 11:21:55 EST




On 7/1/23 07:19, Fabio M. De Francesco wrote:

>
> v1->v2: I thought to Cc everybody but Andrew :-( Sorry, fixed.
> Andrew, can you please take this patch through your tree?
>
> Documentation/mm/highmem.rst | 27 +++++++++++++++------------
> 1 file changed, 15 insertions(+), 12 deletions(-)
>
> diff --git a/Documentation/mm/highmem.rst b/Documentation/mm/highmem.rst
> index c964e0848702..bb9584f167a6 100644
> --- a/Documentation/mm/highmem.rst
> +++ b/Documentation/mm/highmem.rst
> @@ -51,11 +51,14 @@ Temporary Virtual Mappings
> The kernel contains several ways of creating temporary mappings. The following
> list shows them in order of preference of use.
>
> -* kmap_local_page(). This function is used to require short term mappings.
> - It can be invoked from any context (including interrupts) but the mappings
> - can only be used in the context which acquired them.
> -
> - This function should always be used, whereas kmap_atomic() and kmap() have
> +* kmap_local_page(), kmap_local_folio() - These functions are used to require

acquire ?

> + short term mappings. They can be invoked from any context (including
> + interrupts) but the mappings can only be used in the context which acquired
> + them. The only differences between them consist in the first taking a pointer
> + to a struct page and the second taking a pointer to struct folio and the byte
> + offset within the folio which identifies the page.

--
~Randy