Re: [PATCH v3 1/5] mm/page_reporting: add PAGE_REPORTING_ORDER_UNSPECIFIED
From: David Hildenbrand (Arm)
Date: Tue Mar 03 2026 - 05:05:42 EST
On 3/3/26 10:33, Yuvraj Sakshith wrote:
> Drivers can pass order of pages to be reported while
> registering itself. Today, this is a magic number, 0.
>
> Label this with PAGE_REPORTING_ORDER_UNSPECIFIED and
> check for it when the driver is being registered.
>
> This macro will be used in relevant drivers next.
>
> Signed-off-by: Yuvraj Sakshith <yuvraj.sakshith@xxxxxxxxxxxxxxxx>
> ---
> include/linux/page_reporting.h | 1 +
> mm/page_reporting.c | 5 +++--
> 2 files changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/include/linux/page_reporting.h b/include/linux/page_reporting.h
> index fe648dfa3..d1886c657 100644
> --- a/include/linux/page_reporting.h
> +++ b/include/linux/page_reporting.h
> @@ -7,6 +7,7 @@
>
> /* This value should always be a power of 2, see page_reporting_cycle() */
> #define PAGE_REPORTING_CAPACITY 32
> +#define PAGE_REPORTING_ORDER_UNSPECIFIED 0
>
> struct page_reporting_dev_info {
> /* function that alters pages to make them "reported" */
> diff --git a/mm/page_reporting.c b/mm/page_reporting.c
> index e4c428e61..40a756b60 100644
> --- a/mm/page_reporting.c
> +++ b/mm/page_reporting.c
> @@ -369,8 +369,9 @@ int page_reporting_register(struct page_reporting_dev_info *prdev)
> * pageblock_order.
> */
>
> - if (page_reporting_order == -1) {
> - if (prdev->order > 0 && prdev->order <= MAX_PAGE_ORDER)
> + if (page_reporting_order == PAGE_REPORTING_ORDER_UNSPECIFIED) {
This change must also go to #5.
> + if (prdev->order != PAGE_REPORTING_ORDER_UNSPECIFIED &&
> + prdev->order <= MAX_PAGE_ORDER)
> page_reporting_order = prdev->order;
> else
> page_reporting_order = pageblock_order;
--
Cheers,
David