[PATCH 0/2] docs/ksm: fix advisor documentation and comment

[PATCH 0/2] docs/ksm: fix advisor documentation and comment

[Jinjiang Tu]

Fix typos and misleading description of advisor_min_pages_to_scan.

Jinjiang Tu (2):
  docs: ksm: fix typos in sysfs knob names
  mm/ksm: fix advisor_min_pages_to_scan description

 Documentation/admin-guide/mm/ksm.rst | 8 ++++----
 mm/ksm.c                             | 2 +-
 2 files changed, 5 insertions(+), 5 deletions(-)

--
2.54.0

[PATCH 1/2] docs: ksm: fix typos in sysfs knob names

[Jinjiang Tu]

The sysfs knob names in mm/ksm.c are "advisor_max_cpu" and
"advisor_max_pages_to_scan", but the ksm.rst documentation spelled
both as "adivsor_*", fix the two typos.

Fixes: 0710f38ad26a ("mm/ksm: document ksm advisor and its sysfs knobs")
Signed-off-by: Jinjiang Tu <tujinjiang@huawei.com>
---
 Documentation/admin-guide/mm/ksm.rst | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Documentation/admin-guide/mm/ksm.rst b/Documentation/admin-guide/mm/ksm.rst
index ad8e7a41f3b5..c9f533b10f6f 100644
--- a/Documentation/admin-guide/mm/ksm.rst
+++ b/Documentation/admin-guide/mm/ksm.rst
@@ -174,7 +174,7 @@ advisor_mode
         The section about ``advisor`` explains in detail how the scan time
         advisor works.
 
-adivsor_max_cpu
+advisor_max_cpu
         specifies the upper limit of the cpu percent usage of the ksmd
         background thread. The default is 70.
 
@@ -186,7 +186,7 @@ advisor_min_pages_to_scan
         specifies the lower limit of the ``pages_to_scan`` parameter of the
         scan time advisor. The default is 500.
 
-adivsor_max_pages_to_scan
+advisor_max_pages_to_scan
         specifies the upper limit of the ``pages_to_scan`` parameter of the
         scan time advisor. The default is 30000.
 
-- 
2.54.0

Re: [PATCH 1/2] docs: ksm: fix typos in sysfs knob names

[David Hildenbrand (Arm)]

On 7/31/26 10:35, Jinjiang Tu wrote:
> The sysfs knob names in mm/ksm.c are "advisor_max_cpu" and
> "advisor_max_pages_to_scan", but the ksm.rst documentation spelled
> both as "adivsor_*", fix the two typos.
> 
> Fixes: 0710f38ad26a ("mm/ksm: document ksm advisor and its sysfs knobs")

I'm not sure on fixes tags for documentation stuff.

Change itself LGTM

Acked-by: David Hildenbrand (Arm) <david@kernel.org>

-- 
Cheers,

David

Re: [PATCH 1/2] docs: ksm: fix typos in sysfs knob names

[Jinjiang Tu]

在 2026/7/31 17:11, David Hildenbrand (Arm) 写道:
> On 7/31/26 10:35, Jinjiang Tu wrote:
>> The sysfs knob names in mm/ksm.c are "advisor_max_cpu" and
>> "advisor_max_pages_to_scan", but the ksm.rst documentation spelled
>> both as "adivsor_*", fix the two typos.
>>
>> Fixes: 0710f38ad26a ("mm/ksm: document ksm advisor and its sysfs knobs")
> I'm not sure on fixes tags for documentation stuff.

git log --grep "Fixes" Documentation/

Many commits in Documentation have fix tag.
I think both are ok, since documentation changes are needed to backport.

> Change itself LGTM
>
> Acked-by: David Hildenbrand (Arm) <david@kernel.org>
>

Re: [PATCH 1/2] docs: ksm: fix typos in sysfs knob names

[David Hildenbrand (Arm)]

On 7/31/26 11:22, Jinjiang Tu wrote:
> 
> 在 2026/7/31 17:11, David Hildenbrand (Arm) 写道:
>> On 7/31/26 10:35, Jinjiang Tu wrote:
>>> The sysfs knob names in mm/ksm.c are "advisor_max_cpu" and
>>> "advisor_max_pages_to_scan", but the ksm.rst documentation spelled
>>> both as "adivsor_*", fix the two typos.
>>>
>>> Fixes: 0710f38ad26a ("mm/ksm: document ksm advisor and its sysfs knobs")
>> I'm not sure on fixes tags for documentation stuff.
> 
> git log --grep "Fixes" Documentation/
> 
> Many commits in Documentation have fix tag.
> I think both are ok, since documentation changes are needed to backport.

What? When? How? Where?

:)

-- 
Cheers,

David

Re: [PATCH 1/2] docs: ksm: fix typos in sysfs knob names

[Jinjiang Tu]

在 2026/7/31 17:25, David Hildenbrand (Arm) 写道:
> On 7/31/26 11:22, Jinjiang Tu wrote:
>> 在 2026/7/31 17:11, David Hildenbrand (Arm) 写道:
>>> On 7/31/26 10:35, Jinjiang Tu wrote:
>>>> The sysfs knob names in mm/ksm.c are "advisor_max_cpu" and
>>>> "advisor_max_pages_to_scan", but the ksm.rst documentation spelled
>>>> both as "adivsor_*", fix the two typos.
>>>>
>>>> Fixes: 0710f38ad26a ("mm/ksm: document ksm advisor and its sysfs knobs")
>>> I'm not sure on fixes tags for documentation stuff.
>> git log --grep "Fixes" Documentation/
>>
>> Many commits in Documentation have fix tag.
>> I think both are ok, since documentation changes are needed to backport.
> What? When? How? Where?
>
> :)

These commits only modify Documentation/ files and contains fix tags.

0c13ed77dd2b Docs/admin-guide/mm/damon/lru_sort: warn commit_inputs vs param updates race
0beba407d458 Docs/admin-guide/mm/damon/reclaim: warn commit_inputs vs param updates race
d7f00084f686 Docs/admin-guide/mm/damn/lru_sort: fix intervals autotune parameter name
652e1a51465f mm: fix docs for the kernel parameter ``thp_anon=``
14e70e4660d6 Docs/admin-guide/mm/damon/usage: fix wrong schemes effective quota update command
da2a06188888 Docs/admin-guide/mm/damon/usage: fix wrong example of DAMOS filter matching sysfs file
1beb8ae302a0 Docs/admin-guide/mm/zswap: remove zsmalloc's lack of writeback warning
0ff11f103f5d Docs/admin-guide/mm/damon: rename the title of the document
465d0eb0dc31 Docs/admin-guide/mm/damon/usage: fix the example code snip
205498012513 Docs/admin-guide/damon/reclaim: remove a paragraph that been obsolete due to online tuning support
dd21bfa425c0 proc: fix documentation and description of pagemap
a8db400f997c memory-hotplug.rst: fix wrong /sys/module/memory_hotplug/parameters/ path
d83fe3c99d27 memory-hotplug.rst: fix two instances of "movablecore" that should be "movable_node"
72a3e3e25a51 docs: hugetlbpage.rst: fix some warnings
8867f6109b84 docs: fix numaperf.rst and add it to the doc tree


But there are also commits don't contain fix tags. Such as:

abdca14655fe Docs/admin-guide/mm/damon: fix 'parametrs' typo
78a00cac1e96 docs: fix 're-use' -> 'reuse' in documentation
eb14b12c8c22 Docs/admin-guide/mm/damon/usage: fix and add missing DAMOS filter sysfs files on files hierarchy
472098f23323 docs: mm: fix the incorrect 'FileHugeMapped' field

>

Re: [PATCH 1/2] docs: ksm: fix typos in sysfs knob names

[David Hildenbrand (Arm)]

On 8/3/26 09:15, Jinjiang Tu wrote:
> 
> 在 2026/7/31 17:25, David Hildenbrand (Arm) 写道:
>> On 7/31/26 11:22, Jinjiang Tu wrote:
>>> 在 2026/7/31 17:11, David Hildenbrand (Arm) 写道:
>>> git log --grep "Fixes" Documentation/
>>>
>>> Many commits in Documentation have fix tag.
>>> I think both are ok, since documentation changes are needed to backport.
>> What? When? How? Where?
>>
>> :)
> 
> These commits only modify Documentation/ files and contains fix tags.
> 
> 0c13ed77dd2b Docs/admin-guide/mm/damon/lru_sort: warn commit_inputs vs param updates race
> 0beba407d458 Docs/admin-guide/mm/damon/reclaim: warn commit_inputs vs param updates race
> d7f00084f686 Docs/admin-guide/mm/damn/lru_sort: fix intervals autotune parameter name
> 652e1a51465f mm: fix docs for the kernel parameter ``thp_anon=``
> 14e70e4660d6 Docs/admin-guide/mm/damon/usage: fix wrong schemes effective quota update command
> da2a06188888 Docs/admin-guide/mm/damon/usage: fix wrong example of DAMOS filter matching sysfs file
> 1beb8ae302a0 Docs/admin-guide/mm/zswap: remove zsmalloc's lack of writeback warning
> 0ff11f103f5d Docs/admin-guide/mm/damon: rename the title of the document
> 465d0eb0dc31 Docs/admin-guide/mm/damon/usage: fix the example code snip
> 205498012513 Docs/admin-guide/damon/reclaim: remove a paragraph that been obsolete due to online tuning support
> dd21bfa425c0 proc: fix documentation and description of pagemap
> a8db400f997c memory-hotplug.rst: fix wrong /sys/module/memory_hotplug/parameters/ path
> d83fe3c99d27 memory-hotplug.rst: fix two instances of "movablecore" that should be "movable_node"
> 72a3e3e25a51 docs: hugetlbpage.rst: fix some warnings
> 8867f6109b84 docs: fix numaperf.rst and add it to the doc tree
> 
> 
> But there are also commits don't contain fix tags. Such as:
> 
> abdca14655fe Docs/admin-guide/mm/damon: fix 'parametrs' typo
> 78a00cac1e96 docs: fix 're-use' -> 'reuse' in documentation
> eb14b12c8c22 Docs/admin-guide/mm/damon/usage: fix and add missing DAMOS filter sysfs files on files hierarchy
> 472098f23323 docs: mm: fix the incorrect 'FileHugeMapped' field

That is not what I asked. You said "since documentation changes are needed to backport".

Who backports documentation fixes and to which tree?

We usually don't backport anything unless we Cc: stable. And distros don't generally
care that much about documentation backports either.

-- 
Cheers,

David

Re: [PATCH 1/2] docs: ksm: fix typos in sysfs knob names

[Jinjiang Tu]

在 2026/8/3 15:54, David Hildenbrand (Arm) 写道:
> On 8/3/26 09:15, Jinjiang Tu wrote:
>> 在 2026/7/31 17:25, David Hildenbrand (Arm) 写道:
>>> On 7/31/26 11:22, Jinjiang Tu wrote:
>>>> 在 2026/7/31 17:11, David Hildenbrand (Arm) 写道:
>>>> git log --grep "Fixes" Documentation/
>>>>
>>>> Many commits in Documentation have fix tag.
>>>> I think both are ok, since documentation changes are needed to backport.
>>> What? When? How? Where?
>>>
>>> :)
>> These commits only modify Documentation/ files and contains fix tags.
>>
>> 0c13ed77dd2b Docs/admin-guide/mm/damon/lru_sort: warn commit_inputs vs param updates race
>> 0beba407d458 Docs/admin-guide/mm/damon/reclaim: warn commit_inputs vs param updates race
>> d7f00084f686 Docs/admin-guide/mm/damn/lru_sort: fix intervals autotune parameter name
>> 652e1a51465f mm: fix docs for the kernel parameter ``thp_anon=``
>> 14e70e4660d6 Docs/admin-guide/mm/damon/usage: fix wrong schemes effective quota update command
>> da2a06188888 Docs/admin-guide/mm/damon/usage: fix wrong example of DAMOS filter matching sysfs file
>> 1beb8ae302a0 Docs/admin-guide/mm/zswap: remove zsmalloc's lack of writeback warning
>> 0ff11f103f5d Docs/admin-guide/mm/damon: rename the title of the document
>> 465d0eb0dc31 Docs/admin-guide/mm/damon/usage: fix the example code snip
>> 205498012513 Docs/admin-guide/damon/reclaim: remove a paragraph that been obsolete due to online tuning support
>> dd21bfa425c0 proc: fix documentation and description of pagemap
>> a8db400f997c memory-hotplug.rst: fix wrong /sys/module/memory_hotplug/parameters/ path
>> d83fe3c99d27 memory-hotplug.rst: fix two instances of "movablecore" that should be "movable_node"
>> 72a3e3e25a51 docs: hugetlbpage.rst: fix some warnings
>> 8867f6109b84 docs: fix numaperf.rst and add it to the doc tree
>>
>>
>> But there are also commits don't contain fix tags. Such as:
>>
>> abdca14655fe Docs/admin-guide/mm/damon: fix 'parametrs' typo
>> 78a00cac1e96 docs: fix 're-use' -> 'reuse' in documentation
>> eb14b12c8c22 Docs/admin-guide/mm/damon/usage: fix and add missing DAMOS filter sysfs files on files hierarchy
>> 472098f23323 docs: mm: fix the incorrect 'FileHugeMapped' field
> That is not what I asked. You said "since documentation changes are needed to backport".
>
> Who backports documentation fixes and to which tree?

Sorry, I misspelled the word, what I originally meant was"since documentation changes don't need to be backported".

>
> We usually don't backport anything unless we Cc: stable. And distros don't generally
> care that much about documentation backports either.
>

Re: [PATCH 1/2] docs: ksm: fix typos in sysfs knob names

[Lorenzo Stoakes (ARM)]

On Fri, Jul 31, 2026 at 04:35:25PM +0800, Jinjiang Tu wrote:
> The sysfs knob names in mm/ksm.c are "advisor_max_cpu" and
> "advisor_max_pages_to_scan", but the ksm.rst documentation spelled
> both as "adivsor_*", fix the two typos.
>
> Fixes: 0710f38ad26a ("mm/ksm: document ksm advisor and its sysfs knobs")

Same comment as David :)

> Signed-off-by: Jinjiang Tu <tujinjiang@huawei.com>

Anyway LGTM, so:

Reviewed-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>

> ---
>  Documentation/admin-guide/mm/ksm.rst | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/Documentation/admin-guide/mm/ksm.rst b/Documentation/admin-guide/mm/ksm.rst
> index ad8e7a41f3b5..c9f533b10f6f 100644
> --- a/Documentation/admin-guide/mm/ksm.rst
> +++ b/Documentation/admin-guide/mm/ksm.rst
> @@ -174,7 +174,7 @@ advisor_mode
>          The section about ``advisor`` explains in detail how the scan time
>          advisor works.
>
> -adivsor_max_cpu
> +advisor_max_cpu
>          specifies the upper limit of the cpu percent usage of the ksmd
>          background thread. The default is 70.
>
> @@ -186,7 +186,7 @@ advisor_min_pages_to_scan
>          specifies the lower limit of the ``pages_to_scan`` parameter of the
>          scan time advisor. The default is 500.
>
> -adivsor_max_pages_to_scan
> +advisor_max_pages_to_scan
>          specifies the upper limit of the ``pages_to_scan`` parameter of the
>          scan time advisor. The default is 30000.
>
> --
> 2.54.0
>

--
Cheers, Lorenzo

[PATCH 2/2] mm/ksm: fix advisor_min_pages_to_scan description

[Jinjiang Tu]

Both Documentation/admin-guide/mm/ksm.rst and the comment next to the
variable definition in mm/ksm.c describe advisor_min_pages_to_scan as a
lower limit of the pages_to_scan parameter, but that is not how the
scan-time advisor actually uses it. commit 4e5fa4f5eff6 ("mm/ksm: add ksm
advisor") only uses it to initialize ksm_thread_pages_to_scan when the
scan-time advisor is enabled. This will mislead the users.

The semantics of advisor_min_pages_to_scan was updated in the v2 patchset
[1], but the documention wasn't updated.

Update the documentation and comment to match the semantics of
advisor_min_pages_to_scan.

Link: https://lore.kernel.org/linux-mm/20231028000945.2428830-2-shr@devkernel.io/ [1]
Fixes: 0710f38ad26a ("mm/ksm: document ksm advisor and its sysfs knobs")
Fixes: 66790e9a735b ("mm/ksm: add sysfs knobs for advisor")
Signed-off-by: Jinjiang Tu <tujinjiang@huawei.com>
---
 Documentation/admin-guide/mm/ksm.rst | 4 ++--
 mm/ksm.c                             | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/Documentation/admin-guide/mm/ksm.rst b/Documentation/admin-guide/mm/ksm.rst
index c9f533b10f6f..c329ca747b8c 100644
--- a/Documentation/admin-guide/mm/ksm.rst
+++ b/Documentation/admin-guide/mm/ksm.rst
@@ -183,8 +183,8 @@ advisor_target_scan_time
         pages. The default value is 200 seconds.
 
 advisor_min_pages_to_scan
-        specifies the lower limit of the ``pages_to_scan`` parameter of the
-        scan time advisor. The default is 500.
+        specifies the initial value of the ``pages_to_scan`` parameter of
+        the scan time advisor. The default is 500.
 
 advisor_max_pages_to_scan
         specifies the upper limit of the ``pages_to_scan`` parameter of the
diff --git a/mm/ksm.c b/mm/ksm.c
index 7d5b76478f0b..1e3a9c657a64 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -342,7 +342,7 @@ static enum ksm_advisor_type ksm_advisor;
  * Only called through the sysfs control interface:
  */
 
-/* At least scan this many pages per batch. */
+/* Initial number of pages to scan per batch when the scan-time advisor is enabled. */
 static unsigned long ksm_advisor_min_pages_to_scan = 500;
 
 static void set_advisor_defaults(void)
-- 
2.54.0

Re: [PATCH 2/2] mm/ksm: fix advisor_min_pages_to_scan description

[David Hildenbrand (Arm)]

On 7/31/26 10:35, Jinjiang Tu wrote:
> Both Documentation/admin-guide/mm/ksm.rst and the comment next to the
> variable definition in mm/ksm.c describe advisor_min_pages_to_scan as a
> lower limit of the pages_to_scan parameter, but that is not how the
> scan-time advisor actually uses it. commit 4e5fa4f5eff6 ("mm/ksm: add ksm
> advisor") only uses it to initialize ksm_thread_pages_to_scan when the
> scan-time advisor is enabled. This will mislead the users.
> 
> The semantics of advisor_min_pages_to_scan was updated in the v2 patchset
> [1], but the documention wasn't updated.

s/documention/documentation/

> 
> Update the documentation and comment to match the semantics of
> advisor_min_pages_to_scan.
> 
> Link: https://lore.kernel.org/linux-mm/20231028000945.2428830-2-shr@devkernel.io/ [1]
> Fixes: 0710f38ad26a ("mm/ksm: document ksm advisor and its sysfs knobs")
> Fixes: 66790e9a735b ("mm/ksm: add sysfs knobs for advisor")

Drop these.

> Signed-off-by: Jinjiang Tu <tujinjiang@huawei.com>
> ---
>  Documentation/admin-guide/mm/ksm.rst | 4 ++--
>  mm/ksm.c                             | 2 +-
>  2 files changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/Documentation/admin-guide/mm/ksm.rst b/Documentation/admin-guide/mm/ksm.rst
> index c9f533b10f6f..c329ca747b8c 100644
> --- a/Documentation/admin-guide/mm/ksm.rst
> +++ b/Documentation/admin-guide/mm/ksm.rst
> @@ -183,8 +183,8 @@ advisor_target_scan_time
>          pages. The default value is 200 seconds.
>  
>  advisor_min_pages_to_scan
> -        specifies the lower limit of the ``pages_to_scan`` parameter of the
> -        scan time advisor. The default is 500.
> +        specifies the initial value of the ``pages_to_scan`` parameter of
> +        the scan time advisor. The default is 500.

Makes sense.

>  
>  advisor_max_pages_to_scan
>          specifies the upper limit of the ``pages_to_scan`` parameter of the
> diff --git a/mm/ksm.c b/mm/ksm.c
> index 7d5b76478f0b..1e3a9c657a64 100644
> --- a/mm/ksm.c
> +++ b/mm/ksm.c
> @@ -342,7 +342,7 @@ static enum ksm_advisor_type ksm_advisor;
>   * Only called through the sysfs control interface:
>   */
>  
> -/* At least scan this many pages per batch. */
> +/* Initial number of pages to scan per batch when the scan-time advisor is enabled. */
>  static unsigned long ksm_advisor_min_pages_to_scan = 500;
"when the scan-time advisor is enabled" is clear from the variable name.

So I'd shorten it to "Initial number of pages to scan per batch"

-- 
Cheers,

David

Re: [PATCH 2/2] mm/ksm: fix advisor_min_pages_to_scan description

[Jinjiang Tu]

在 2026/7/31 17:17, David Hildenbrand (Arm) 写道:
> On 7/31/26 10:35, Jinjiang Tu wrote:
>> Both Documentation/admin-guide/mm/ksm.rst and the comment next to the
>> variable definition in mm/ksm.c describe advisor_min_pages_to_scan as a
>> lower limit of the pages_to_scan parameter, but that is not how the
>> scan-time advisor actually uses it. commit 4e5fa4f5eff6 ("mm/ksm: add ksm
>> advisor") only uses it to initialize ksm_thread_pages_to_scan when the
>> scan-time advisor is enabled. This will mislead the users.
>>
>> The semantics of advisor_min_pages_to_scan was updated in the v2 patchset
>> [1], but the documention wasn't updated.
> s/documention/documentation/
>
>> Update the documentation and comment to match the semantics of
>> advisor_min_pages_to_scan.
>>
>> Link: https://lore.kernel.org/linux-mm/20231028000945.2428830-2-shr@devkernel.io/ [1]
>> Fixes: 0710f38ad26a ("mm/ksm: document ksm advisor and its sysfs knobs")
>> Fixes: 66790e9a735b ("mm/ksm: add sysfs knobs for advisor")
> Drop these.
>
>> Signed-off-by: Jinjiang Tu <tujinjiang@huawei.com>
>> ---
>>   Documentation/admin-guide/mm/ksm.rst | 4 ++--
>>   mm/ksm.c                             | 2 +-
>>   2 files changed, 3 insertions(+), 3 deletions(-)
>>
>> diff --git a/Documentation/admin-guide/mm/ksm.rst b/Documentation/admin-guide/mm/ksm.rst
>> index c9f533b10f6f..c329ca747b8c 100644
>> --- a/Documentation/admin-guide/mm/ksm.rst
>> +++ b/Documentation/admin-guide/mm/ksm.rst
>> @@ -183,8 +183,8 @@ advisor_target_scan_time
>>           pages. The default value is 200 seconds.
>>   
>>   advisor_min_pages_to_scan
>> -        specifies the lower limit of the ``pages_to_scan`` parameter of the
>> -        scan time advisor. The default is 500.
>> +        specifies the initial value of the ``pages_to_scan`` parameter of
>> +        the scan time advisor. The default is 500.
> Makes sense.
>
>>   
>>   advisor_max_pages_to_scan
>>           specifies the upper limit of the ``pages_to_scan`` parameter of the
>> diff --git a/mm/ksm.c b/mm/ksm.c
>> index 7d5b76478f0b..1e3a9c657a64 100644
>> --- a/mm/ksm.c
>> +++ b/mm/ksm.c
>> @@ -342,7 +342,7 @@ static enum ksm_advisor_type ksm_advisor;
>>    * Only called through the sysfs control interface:
>>    */
>>   
>> -/* At least scan this many pages per batch. */
>> +/* Initial number of pages to scan per batch when the scan-time advisor is enabled. */
>>   static unsigned long ksm_advisor_min_pages_to_scan = 500;
> "when the scan-time advisor is enabled" is clear from the variable name.
>
> So I'd shorten it to "Initial number of pages to scan per batch"

Thanks, will update these.