Re: [PATCH v1] mm/ksm: add pages scanned metric

[David Hildenbrand]

On 11.08.23 21:36, Stefan Roesch wrote:
> ksm currently maintains several statistics, which let you determine how
> successful KSM is at sharing pages. However it does not contain a metric
> to determine how much work it does.
>
> This commit adds the pages scanned metric. This allows the administrator
> to determine how many pages have been scanned over a period of time.
>
> Signed-off-by: Stefan Roesch <shr@xxxxxxxxxxxx>
> ---
>   Documentation/admin-guide/mm/ksm.rst |  2 ++
>   mm/ksm.c                             | 16 +++++++++++++++-
>   2 files changed, 17 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/admin-guide/mm/ksm.rst b/Documentation/admin-guide/mm/ksm.rst
> index 5c5be7bd84b8..776f244bdae4 100644
> --- a/Documentation/admin-guide/mm/ksm.rst
> +++ b/Documentation/admin-guide/mm/ksm.rst
> @@ -159,6 +159,8 @@ The effectiveness of KSM and MADV_MERGEABLE is shown in ``/sys/kernel/mm/ksm/``:
>   
>   general_profit
>           how effective is KSM. The calculation is explained below.
> +pages_scanned
> +        how many pages are being scanned for ksm
>   pages_shared
>           how many shared pages are being used
>   pages_sharing
> diff --git a/mm/ksm.c b/mm/ksm.c
> index 6b7b8928fb96..8d6aee05421d 100644
> --- a/mm/ksm.c
> +++ b/mm/ksm.c
> @@ -242,6 +242,9 @@ static struct kmem_cache *rmap_item_cache;
>   static struct kmem_cache *stable_node_cache;
>   static struct kmem_cache *mm_slot_cache;
>   
> +/* The number of pages scanned */
> +static unsigned long ksm_pages_scanned;
> +

LGTM

Acked-by: David Hildenbrand <david@xxxxxxxxxx>

--
Cheers,

David / dhildenb