[PATCH] mm/damon/core: add short circuit for esz<min_region_sz in damos_adjust_quota()

[Liew Rui Yan]

After damos_set_effective_quota(), the effective size quota may be lower
than min_region_sz (e.g., when the temporal quota goal is
[over-]achieved).

In this situation, damos_adjust_quota() will still calculates
quota->min_score.  However, this min_score will not be used in this
window, because in damon_do_apply_schemes(), damos_quota_is_full() will
always returns true, preventing the scheme from being applied to any
region.

Therefore, add a short circuit for 'esz < min_region_sz' schemes to
early return from damos_adjust_quota() before calculating min_score.

Signed-off-by: Liew Rui Yan <aethernet65535@xxxxxxxxx>
---

Changes from RFC v1:
- RFC v1: https://lore.kernel.org/damon/20260912124406.96535-1-aethernet65535@xxxxxxxxx
- Make patch more complete by covering 'esz < min_region_sz' instead of
  covering "temporal quota goal is [over-]achieved" only.

---
 mm/damon/core.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/mm/damon/core.c b/mm/damon/core.c
index ce8c6f99106e..15758525765e 100644
--- a/mm/damon/core.c
+++ b/mm/damon/core.c
@@ -3318,6 +3318,8 @@ static void damos_adjust_quota(struct damon_ctx *c, struct damos *s)
 			damos_trace_esz(c, s, quota);
 	}
 
+	if (damos_quota_is_full(quota, c->min_region_sz))
+		return;
 	if (!c->ops.get_scheme_score)
 		return;
 
-- 
2.55.0