Re: [PATCH] mm/damon/tests/core-kunit: test damon_nr_accesses_mvsum()

[SJ Park <sj@kernel.org>]

On Fri, 10 Jul 2026 12:15:30 +0800 Song Hu <husong@kylinos.cn> wrote:

> damon_nr_accesses_mvsum() wraps damon_mvsum() with the monitoring
> intervals of the context to compute the pseudo moving sum of a region's
> access frequency, with a special case for when the whole aggregation
> window remains. damon_mvsum() itself is already covered by
> damon_test_mvsum(), but the wrapper is not.
> 
> Add a table-driven KUnit test that exercises the full-window-remaining
> boundary (with both reset and not-yet-reset nr_accesses), partially
> elapsed windows, and the no-window-remaining case.

Nice!  Thank you!

> 
> Signed-off-by: Song Hu <husong@kylinos.cn>
> ---
>  mm/damon/tests/core-kunit.h | 49 +++++++++++++++++++++++++++++++++++++
>  1 file changed, 49 insertions(+)
> 
> diff --git a/mm/damon/tests/core-kunit.h b/mm/damon/tests/core-kunit.h
> index 0124f83b39b8..8c030282a638 100644
> --- a/mm/damon/tests/core-kunit.h
> +++ b/mm/damon/tests/core-kunit.h
> @@ -683,6 +683,54 @@ static void damon_test_mvsum(struct kunit *test)
>  	}
>  }
>  
> +/*
> + * Test damon_nr_accesses_mvsum(), which wraps damon_mvsum() with the monitoring

Please wrap lines [1] for 80 columns limit.

> + * intervals of the context.  With a sample interval of 1 and an aggregation
> + * interval of 10, an aggregation window is 10 sample intervals long.  Each row
> + * below specifies the passed sample intervals, the next aggregation time in
> + * sample intervals, the current and last nr_accesses of a region, and the
> + * expected return value.
> + */
> +static void damon_test_nr_accesses_mvsum(struct kunit *test)
> +{
> +	unsigned long input_expects[] = {
> +		/* passed, next_aggr, nr_accesses, last_nr_accesses, expect */
> +		0, 10, 5, 3, 3,		/* bp=10000: unreset nr_accesses ignored */

I was bit confused what 'bp' means.  Can we just drop 'bp=...:' part from the
comment?

Also, let's keep the 80 columns limit.

[...]

Other than those, looks good to me!

[1] https://docs.kernel.org/process/coding-style.html#breaking-long-lines-and-strings


Thanks,
SJ