[merged mm-stable] documentation-add-ksm_stat-description-in-cgroup-v1-memoryrst.patch removed from -mm tree

[merged mm-stable] documentation-add-ksm_stat-description-in-cgroup-v1-memoryrst.patch removed from -mm tree

[Andrew Morton]

The quilt patch titled
     Subject: Documentation: add ksm_stat description in cgroup-v1/memory.rst
has been removed from the -mm tree.  Its filename was
     documentation-add-ksm_stat-description-in-cgroup-v1-memoryrst.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: xu xin <xu.xin16@zte.com.cn>
Subject: Documentation: add ksm_stat description in cgroup-v1/memory.rst
Date: Thu, 1 May 2025 04:17:13 +0000

This updates ksm_stat description in cgroup-v1/memory.rst.

Link: https://lkml.kernel.org/r/20250501041713.3324621-1-xu.xin16@zte.com.cn
Signed-off-by: xu xin <xu.xin16@zte.com.cn>
Cc: David Hildenbrand <david@redhat.com>
Cc: Haonan Chen <chen.haonan2@zte.com.cn>
Cc: Wang Yaxin <wang.yaxin@zte.com.cn>
Cc: Yang Yang <yang.yang29@zte.com.cn>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 Documentation/admin-guide/cgroup-v1/memory.rst |   36 +++++++++++++++
 1 file changed, 36 insertions(+)

--- a/Documentation/admin-guide/cgroup-v1/memory.rst~documentation-add-ksm_stat-description-in-cgroup-v1-memoryrst
+++ a/Documentation/admin-guide/cgroup-v1/memory.rst
@@ -97,6 +97,8 @@ Brief summary of control files.
                                      used.
  memory.numa_stat		     show the number of memory usage per numa
 				     node
+ memory.ksm_stat                     show the statistic information about various ksm
+                                     counters
  memory.kmem.limit_in_bytes          Deprecated knob to set and read the kernel
                                      memory hard limit. Kernel hard limit is not
                                      supported since 5.16. Writing any value to
@@ -674,6 +676,40 @@ The output format of memory.numa_stat is
 
 The "total" count is sum of file + anon + unevictable.
 
+.. _memcg_ksm_stat:
+
+5.7 ksm_stat
+------------
+
+When CONFIG_KSM is enabled, the ksm_stat file can be used to observe the ksm
+merging status of the processes within an memory cgroup.
+
+The output format of memory.ksm_stat is::
+
+  ksm_rmap_items <number>
+  ksm_zero_pages <number>
+  ksm_merging_pages <number>
+  ksm_profit <number>
+
+The "ksm_rmap_items" count specifies the number of ksm_rmap_item structures in
+use. The structureksm_rmap_item stores the reverse mapping information for
+virtual addresses.  KSM will generate a ksm_rmap_item for each ksm-scanned page
+of the process.
+
+The "ksm_zero_pages" count specifies represent how many empty pages are merged
+with kernel zero pages by KSM, which is useful when /sys/kernel/mm/ksm/use_zero_pages
+is enabled.
+
+The "ksm_merging_pages" count specifies how many pages of this process are involved
+in KSM merging (not including ksm_zero_pages).
+
+The "ksm_process_profit" count specifies the profit that KSM brings (Saved bytes).
+KSM can save memory by merging identical pages, but also can consume additional
+memory, because it needs to generate a number of rmap_items to save each scanned
+page's brief rmap information. Some of these pages may be merged, but some may not
+be abled to be merged after being checked several times, which are unprofitable
+memory consumed.
+
 6. Hierarchy support
 ====================
 
_

Patches currently in -mm which might be from xu.xin16@zte.com.cn are