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

David Hildenbrand
2023-08-15T07:28:22Z

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@devkernel.io>
> ---
> 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@redhat.com>

--
Cheers,

David / dhildenb