Re: [RFC PATCH v2.1 01/17] mm/damon/core: introduce DAMON_FILTER_TYPE_PGIDLE_UNSET

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] The patch introduces `DAMON_FILTER_TYPE_PGIDLE_UNSET` but fails to implement its matching logic or expose it via sysfs.
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--- Patch [1]: [RFC PATCH v2.1 01/17] mm/damon/core: introduce DAMON_FILTER_TYPE_PGIDLE_UNSET ---
commit 713d89253715d0f67d20248547ddafe132444f89
Author: SJ Park <[email protected]>

mm/damon/core: introduce DAMON_FILTER_TYPE_PGIDLE_UNSET

This commit introduces a new DAMON filter type, pgidle_unset. It is intended
to match pages that have their PG_Idle flag unset or the page table accessed
bit set.

> diff --git a/include/linux/damon.h b/include/linux/damon.h
> index 0c8b7ddef9abb..a8bb9ee6979e3 100644
> --- a/include/linux/damon.h
> +++ b/include/linux/damon.h
> @@ -742,12 +742,14 @@ struct damon_intervals_goal {
>  /**
>   * enum damon_filter_type - Type of &struct damon_filter
>   *
> - * @DAMON_FILTER_TYPE_ANON:		Anonymous pages.
> - * @DAMON_FILTER_TYPE_MEMCG:		Specific memcg's pages.
> + * @DAMON_FILTER_TYPE_ANON:		Anonymous pages.
> + * @DAMON_FILTER_TYPE_MEMCG:		Specific memcg's pages.
> + * @DAMON_FILTER_TYPE_PGIDLE_UNSET:	Pgidle is unset.
>   */
>  enum damon_filter_type {
>  	DAMON_FILTER_TYPE_ANON,
>  	DAMON_FILTER_TYPE_MEMCG,
> +	DAMON_FILTER_TYPE_PGIDLE_UNSET,

[Severity: Medium]
Are the corresponding implementation details for this new filter type missing
from this patch?

The commit message states this will match pages that have their PG_Idle flag
unset, but the new DAMON_FILTER_TYPE_PGIDLE_UNSET variant doesn't appear to
be handled in the switch block evaluating filter types within
damon_pa_filter_match() in mm/damon/paddr.c.

Additionally, should this be exposed to userspace? The new filter type is
not mapped in damon_sysfs_filter_type_names in mm/damon/sysfs.c, which would
prevent it from being configured via sysfs.

>  };
>  
>  /**

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Sashiko AI review · https://sashiko.dev/#/patchset/[email protected]?part=1