Re: [RFC PATCH v2.1 5/7] mm/damon/sysfs-schemes: support probe_hits_wsum damos core filter

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] The commit introduces `DAMOS_FILTER_TYPE_PROBE_HITS_WSUM` to the core layer and updates `damos_commit_filter_arg()` to properly copy its state (`range_min` and `range_max`), but fails to update the corresponding KUnit tests that rigorously check this exact behavior.
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commit 90fc8bb11dba04367743217a5b35954829f87d9c
Author: SJ Park <sj@kernel.org>

mm/damon/sysfs-schemes: support probe_hits_wsum damos core filter

This commit extends the DAMON sysfs interface to support the probe_hits_wsum
input for scheme core filters. It updates the scheme build logic to set up
the min/max probe hits weighted sum range as provided by the user.

> diff --git a/mm/damon/sysfs-schemes.c b/mm/damon/sysfs-schemes.c
> index 4d9147d2a269e..d9dd4ee0442c7 100644
> --- a/mm/damon/sysfs-schemes.c
> +++ b/mm/damon/sysfs-schemes.c

[ ... ]

> @@ -2844,6 +2847,14 @@ static int damon_sysfs_add_scheme_filters(struct damos *scheme,
>  			}
>  			filter->sz_range.min = sysfs_filter->range_min;
>  			filter->sz_range.max = sysfs_filter->range_max;
> +		} else if (filter->type == DAMOS_FILTER_TYPE_PROBE_HITS_WSUM) {
> +			if (sysfs_filter->range_min >
> +					sysfs_filter->range_max) {
> +				damos_destroy_filter(filter);
> +				return -EINVAL;
> +			}
> +			filter->range_min = sysfs_filter->range_min;
> +			filter->range_max = sysfs_filter->range_max;

[Severity: Low]
Does the addition of this new filter type require an update to the core
KUnit tests?

In mm/damon/tests/core-kunit.h, there is a switch statement in
damos_test_commit_filter_for() that checks parameter validation for each
filter type:

	switch (src->type) {
	case DAMOS_FILTER_TYPE_MEMCG:
...
	case DAMOS_FILTER_TYPE_HUGEPAGE_SIZE:
		KUNIT_EXPECT_EQ(test, dst->sz_range.min, src->sz_range.min);
		KUNIT_EXPECT_EQ(test, dst->sz_range.max, src->sz_range.max);
		break;
	default:
		break;
	}

Because DAMOS_FILTER_TYPE_PROBE_HITS_WSUM isn't handled here, it falls
through to the default case, bypassing validation.

Additionally, the orchestrating function damos_test_commit_filter() doesn't
appear to have a test block for this new type. Should these KUnit tests be
updated to maintain test coverage for the new feature?

>  		}
>  
>  		damos_add_filter(scheme, filter);

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260910040319.147037-1-sj@kernel.org?part=5