The quilt patch titled
Subject: mm/ksm: document smart scan mode
has been removed from the -mm tree. Its filename was
mm-ksm-document-smart-scan-mode.patch
This patch was dropped because it was merged into the mm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
------------------------------------------------------
From: Stefan Roesch <shr@xxxxxxxxxxxx>
Subject: mm/ksm: document smart scan mode
Date: Mon, 25 Sep 2023 21:09:38 -0700
This adds documentation for the smart scan mode of KSM.
[akpm@xxxxxxxxxxxxxxxxxxxx: fix typo]
[akpm@xxxxxxxxxxxxxxxxxxxx: document that smart_scan defaults to on]
Link: https://lkml.kernel.org/r/20230926040939.516161-4-shr@xxxxxxxxxxxx
Signed-off-by: Stefan Roesch <shr@xxxxxxxxxxxx>
Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
Documentation/admin-guide/mm/ksm.rst | 9 +++++++++
1 file changed, 9 insertions(+)
--- a/Documentation/admin-guide/mm/ksm.rst~mm-ksm-document-smart-scan-mode
+++ a/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
+ Historically KSM checked every candidate page for each scan. It did
+ 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 enabled. The ``pages_skipped`` metric shows how
+ effective the setting is.
+
The effectiveness of KSM and MADV_MERGEABLE is shown in ``/sys/kernel/mm/ksm/``:
general_profit
_
Patches currently in -mm which might be from shr@xxxxxxxxxxxx are
