[v1,3/4] mm/ksm: document smart scan mode
Commit Message
This adds documentation for the smart scan mode of KSM.
Signed-off-by: Stefan Roesch <shr@devkernel.io>
---
Documentation/admin-guide/mm/ksm.rst | 9 +++++++++
1 file changed, 9 insertions(+)
Comments
On 12.09.23 19:52, Stefan Roesch wrote:
> This adds documentation for the smart scan mode of KSM.
>
> Signed-off-by: Stefan Roesch <shr@devkernel.io>
> ---
> Documentation/admin-guide/mm/ksm.rst | 9 +++++++++
> 1 file changed, 9 insertions(+)
>
> diff --git a/Documentation/admin-guide/mm/ksm.rst b/Documentation/admin-guide/mm/ksm.rst
> index 776f244bdae4..1762219baf51 100644
> --- a/Documentation/admin-guide/mm/ksm.rst
> +++ b/Documentation/admin-guide/mm/ksm.rst
> @@ -155,6 +155,15 @@ stable_node_chains_prune_millisecs
> scan. It's a noop if not a single KSM page hit the
> ``max_page_sharing`` yet.
>
> +smart_scan
> + By default KSM checks every candidate page for each scan. It does
> + not take into account historic information. When smart scan is
> + enabled, pages that have previously not been de-duplicated get
> + skipped. How often these pages are skipped depends on how often
> + de-duplication has already been tried and failed. By default this
> + optimization is disabled. The ``pages_skipped`` metric shows how
> + effetive the setting is.
> +
> The effectiveness of KSM and MADV_MERGEABLE is shown in ``/sys/kernel/mm/ksm/``:
>
> general_profit
Reviewed-by: David Hildenbrand <david@redhat.com>
@@ -155,6 +155,15 @@ stable_node_chains_prune_millisecs
scan. It's a noop if not a single KSM page hit the
``max_page_sharing`` yet.
+smart_scan
+ By default KSM checks every candidate page for each scan. It does
+ not take into account historic information. When smart scan is
+ enabled, pages that have previously not been de-duplicated get
+ skipped. How often these pages are skipped depends on how often
+ de-duplication has already been tried and failed. By default this
+ optimization is disabled. The ``pages_skipped`` metric shows how
+ effetive the setting is.
+
The effectiveness of KSM and MADV_MERGEABLE is shown in ``/sys/kernel/mm/ksm/``:
general_profit