Re: [RFC PATCH v4 5/7] Docs/mm/damon/design: document damos quota goal complement flag

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] kselftest/damon: missing sysfs test coverage for quota goal complement
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commit d3c6455ce7af443b98334d4d8484051c2827e265
Author: SJ Park <sj@kernel.org>

Docs/mm/damon/design: document damos quota goal complement flag

Update DAMON design document for the newly added damos quota goal metric
value complement flag.

> diff --git a/Documentation/mm/damon/design.rst b/Documentation/mm/damon/design.rst
> index e82390e77a70a..5cd651b1b7aa8 100644
> --- a/Documentation/mm/damon/design.rst
> +++ b/Documentation/mm/damon/design.rst
> @@ -702,10 +702,10 @@ There are two such tuning algorithms that users can select as they need.
>    that the zero quota is a valid quota, and therefore ``qt_exceeds`` :ref:`stat
>    <damon_design_damos_stat>` will keep increasing in this case.
>  
> -The goal can be specified with five parameters, namely ``target_metric``,
> -``target_value``, ``current_value``, ``nid`` and ``path``.  The auto-tuning
> -mechanism tries to make ``current_value`` of ``target_metric`` be same to
> -``target_value``.
> +The goal can be specified with six parameters, namely ``target_metric``,
> +``complement``, ``target_value``, ``current_value``, ``nid`` and ``path``.  The
> +auto-tuning mechanism tries to make ``current_value`` of ``complement``-ed
> +``target_metric`` be same to ``target_value``.

[Severity: Low]
Does the kselftest framework need to be updated to cover this new parameter?

Looking at the selftests, test_goal() in
tools/testing/selftests/damon/sysfs.sh explicitly tests for target_metric and
other parameters, but lacks a check for the newly added complement parameter:

    ensure_file "$goal_dir/target_metric" "exist" "600"

Additionally, DamosQuotaGoal.stage() in
tools/testing/selftests/damon/_damon_sysfs.py provides no fields or logic to
set complement:

    err = write_file(os.path.join(self.sysfs_dir(), 'target_metric'),
                     self.metric)

Could we add these test parameters to ensure the new sysfs feature is covered
by the existing framework?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260927120533.50484-1-sj@kernel.org?part=5