mm/damon/paddr: make supported DAMOS actions of paddr clear

Patch series "mm/damon: cleanup code".

DAMON code was not so clean from the beginning, but it has been too much
nowadays, especially due to the duplicates in DAMON_RECLAIM and
DAMON_LRU_SORT.  This patchset cleans some of the mess.


This patch (of 22):

The 'switch-case' statement in 'damon_va_apply_scheme()' function provides
a 'case' for every supported DAMOS action while all not-yet-supported
DAMOS actions fall through the 'default' case, and comment it so that
people can easily know which actions are supported.  Its counterpart in
'paddr', 'damon_pa_apply_scheme()', however, doesn't.  This commit makes
the 'paddr' side function follows the pattern of 'vaddr' for better
readability and consistency.

Link: https://lkml.kernel.org/r/20220913174449.50645-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20220913174449.50645-2-sj@kernel.orgSigned-off-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/damon/paddr.c

@@ -275,7 +275,10 @@ static unsigned long damon_pa_apply_scheme(struct damon_ctx *ctx,
 		return damon_pa_mark_accessed(r);
 	case DAMOS_LRU_DEPRIO:
 		return damon_pa_deactivate_pages(r);
+	case DAMOS_STAT:
+		break;
 	default:
+		/* DAMOS actions that not yet supported by 'paddr'. */
 		break;
 	}
 	return 0;