[PATCH 0/3] mm/damon: fix a minor bug, clean code, and add a test

[PATCH 0/3] mm/damon: fix a minor bug, clean code, and add a test

[SJ Park]

Patch 1 from Jaeyeon Lee fixes a minor overflow issue in DAMOS.  Patch 2
from Gregory Price (Meta) cleans up the code for handling of hugetlb
pages.  Patch 3 from Liew Rui Yan adds a kunit test for a recently fixed
bug.

Note to Andrew.  This is a batched reposting of DAMON patches that I
reviewed and asking for merge into mm.git.  Since there are only two
weeks before the expected opening of the next merge window, this will be
the last mm.git merge requesting unurgent DAMON reposting until the next
rc1.

Gregory Price (1):
  mm/damon: use damon_get_monitor_folio() for hugetlb entries

Jaeyeon Lee (1):
  mm/damon/ops-common: fix age_in_sec overflow on 32-bit

Liew Rui Yan (1):
  mm/damon/tests/core-kunit: add test for unconditionally skipping the
    last region

 mm/damon/ops-common.c       | 11 ++++++----
 mm/damon/tests/core-kunit.h | 42 +++++++++++++++++++++++++++++++++++++
 mm/damon/vaddr.c            | 10 +++++----
 3 files changed, 55 insertions(+), 8 deletions(-)


base-commit: 1b1d9187f46db1efb64533dab8b8d5f4f2af0eb5
-- 
2.47.3

[PATCH 3/3] mm/damon/tests/core-kunit: add test for unconditionally skipping the last region

[SJ Park]

From: Liew Rui Yan <aethernet65535@gmail.com>

Commit b3723b596b54 ("mm/damon/core: fix unconditionally skip last
region") fixed a minor bug.

Add a KUnit test case to cover this behavior and prevent regressions in
the future.

Signed-off-by: Liew Rui Yan <aethernet65535@gmail.com>
Reviewed-by: SJ Park <sj@kernel.org>
Signed-off-by: SJ Park <sj@kernel.org>
---
Changes from v3
- v3: https://lore.kernel.org/20260927175159.60703-1-aethernet65535@gmail.com
- Collect R-b: from SJ.
- Rebase to the latest mm-new.
Changes from v2:
- v2: https://lore.kernel.org/damon/20260925045350.66595-1-aethernet65535@gmail.com
- Change the commit message, mention the fix rather than the original
  bug.
Changes from v1 RESEND:
- v1 RESEND: https://lore.kernel.org/damon/20260919080453.628679-1-aethernet65535@gmail.com
- Drop braces for single line, as suggested [1] in coding-style.
- Set min_region_sz initial value to power-of-2 value, '1'.
Changes from v1:
- v1: https://lore.kernel.org/damon/20260831113735.3349-1-aethernet65535@gmail.com
- Resend since the dependent patch is merged into mm-new, that would
  help us getting AI review help.

 mm/damon/tests/core-kunit.h | 42 +++++++++++++++++++++++++++++++++++++
 1 file changed, 42 insertions(+)

diff --git a/mm/damon/tests/core-kunit.h b/mm/damon/tests/core-kunit.h
index ef146ca2ae8a..3fbb4e4e36fa 100644
--- a/mm/damon/tests/core-kunit.h
+++ b/mm/damon/tests/core-kunit.h
@@ -2439,6 +2439,47 @@ static void damos_test_esz_goal_temporal(struct kunit *test)
 	damon_destroy_ctx(ctx);
 }
 
+static void damon_test_last_region_quota_reset(struct kunit *test)
+{
+	struct damos s = {0};
+	struct damon_target *t;
+	struct damon_region *r1, *r2;
+	unsigned long min_region_sz = 1;
+	bool skipped;
+
+	t = damon_new_target();
+	if (!t)
+		kunit_skip(test, "target alloc fail");
+
+	r1 = damon_new_region(0, 100);
+	if (!r1) {
+		damon_free_target(t);
+		kunit_skip(test, "region 1 alloc fail");
+	}
+	damon_add_region(r1, t);
+
+	r2 = damon_new_region(100, 200);
+	if (!r2) {
+		damon_free_target(t);
+		kunit_skip(test, "region 2 alloc fail");
+	}
+	damon_add_region(r2, t);
+
+	s.quota.charge_target_from = t;
+	s.quota.charge_addr_from = r1->ar.end;
+
+	skipped = damos_skip_charged_region(t, r2, &s, min_region_sz);
+
+	/* 'r2' is not processed, it should not skip */
+	KUNIT_EXPECT_EQ(test, skipped, false);
+
+	/* 'r2' is last region, it should reset charge_{target,addr}_from */
+	KUNIT_EXPECT_PTR_EQ(test, s.quota.charge_target_from, NULL);
+	KUNIT_EXPECT_EQ(test, s.quota.charge_addr_from, 0);
+
+	damon_free_target(t);
+}
+
 static struct kunit_case damon_test_cases[] = {
 	KUNIT_CASE(damon_test_target),
 	KUNIT_CASE(damon_test_regions),
@@ -2482,6 +2523,7 @@ static struct kunit_case damon_test_cases[] = {
 	KUNIT_CASE(damon_test_walk_control_obsolete),
 	KUNIT_CASE(damon_test_rand),
 	KUNIT_CASE(damos_test_esz_goal_temporal),
+	KUNIT_CASE(damon_test_last_region_quota_reset),
 	{},
 };
 
-- 
2.47.3