Re: [PATCH] Docs/admin-guide/mm/damon/reclaim: document how to disable watermarks

[Jinjie Ruan <ruanjinjie@huawei.com>]

在 2026/10/28 13:35, SJ Park 写道:
> On Tue, 27 Oct 2026 22:24:24 -0700 SJ Park <sj@kernel.org> wrote:
> 
>> Hello Jinjie,
>>
>> On Wed, 28 Oct 2026 10:36:28 +0800 Jinjie Ruan <ruanjinjie@huawei.com> wrote:
>>
>>> DAMON_RECLAIM runs its scheme only while the free memory rate is
>>> between `wmarks_low` and `wmarks_mid`.
>>>
>>> But some users want to reclaim cold pages even while the system has
>>> plenty of free memory, and it is not obvious that the existing
>>> watermarks parameters can already do that. So Document the setup.
>>
>> Thank you for this patch!
>>
>>>
>>> Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
>>> ---
>>>  Documentation/admin-guide/mm/damon/reclaim.rst | 7 +++++++
>>>  1 file changed, 7 insertions(+)
>>>
>>> diff --git a/Documentation/admin-guide/mm/damon/reclaim.rst b/Documentation/admin-guide/mm/damon/reclaim.rst
>>> index ec7e3e32b4ac..23fede7d1cdb 100644
>>> --- a/Documentation/admin-guide/mm/damon/reclaim.rst
>>> +++ b/Documentation/admin-guide/mm/damon/reclaim.rst
>>> @@ -193,6 +193,13 @@ DAMON_RECLAIM becomes inactive, so it does nothing but periodically checks the
>>>  watermarks.  In the case, the system falls back to the LRU-list based page
>>>  granularity reclamation logic.
>>>  
>>> +To keep DAMON_RECLAIM always active regardless of the free memory rate, set
>>> +``wmarks_high``, ``wmarks_mid`` and ``wmarks_low`` to ``1000``, ``1000`` and
>>> +``0``, respectively.  Then the reclamation is limited only by ``min_age`` and
>>> +the quotas.  This is useful for reclaiming cold pages even while the system
>>> +has plenty of free memory, e.g., right after an idle virtual machine is
>>> +paused.
>>> +
>>
>> I feel like above might be too detailed.  Particularly, the second sentence
>> looks too detailed.  In a sense, it is not technically correct because of
>> 'skip_anon' parameter.  We might later need to add more such controls, and I
>> concern if this kind of detailed documentation will limit such extensions.
>>
>> What about keeping only the first sentence and dropping later two sentences?
> 
> If you don't mind, I could add this patch to damon/next after dropping the last
> two sentences on my own.

Hi SJ,

It is fine with me, thanks. Please go ahead.

> 
> 
> Thanks,
> SJ
> 
> [...]

-- 
Best regards,
Jinjie