[PATCH 0/6] mm/damon: minor fixups and improvements for code, tests, and documents

[PATCH 0/6] mm/damon: minor fixups and improvements for code, tests, and documents

[SeongJae Park]

Yet another batch of miscellaneous DAMON changes.  Fix and improve minor
problems in code, tests and documents.

SeongJae Park (6):
  mm/damon/core: warn and fix nr_accesses[_bp] corruption
  mm/damon/sysfs-schemes: fix wrong comment on
    damons_sysfs_quota_goal_metric_strs
  mm/damon/paddr: remove unused variable, folio_list, in damon_pa_stat()
  mm/damon/tests/core-kunit: add a test for
    damos_set_filters_default_reject()
  selftests/damon/_damon_sysfs: read tried regions directories in order
  Docs/damon: update titles and brief introductions to explain DAMOS

 Documentation/admin-guide/mm/damon/index.rst  | 11 ++-
 Documentation/mm/damon/index.rst              |  6 +-
 mm/damon/core.c                               | 14 ++++
 mm/damon/paddr.c                              |  1 -
 mm/damon/sysfs-schemes.c                      |  2 +-
 mm/damon/tests/core-kunit.h                   | 70 +++++++++++++++++++
 tools/testing/selftests/damon/_damon_sysfs.py |  5 ++
 7 files changed, 98 insertions(+), 11 deletions(-)


base-commit: fb227aa50d133236ef02a71dd9e3d510f4fad42f
-- 
2.39.5

[PATCH 4/6] mm/damon/tests/core-kunit: add a test for damos_set_filters_default_reject()

[SeongJae Park]

DAMOS filters' default reject behavior is not very simple.  Actually
there was a mistake[1] during the development.  Add a kunit test for
validating the behavior.

[1] https://lore.kernel.org/20250227002913.19359-1-sj@kernel.org

Signed-off-by: SeongJae Park <sj@kernel.org>
---
 mm/damon/tests/core-kunit.h | 70 +++++++++++++++++++++++++++++++++++++
 1 file changed, 70 insertions(+)

diff --git a/mm/damon/tests/core-kunit.h b/mm/damon/tests/core-kunit.h
index be0fea9ee5fc..298c67557fae 100644
--- a/mm/damon/tests/core-kunit.h
+++ b/mm/damon/tests/core-kunit.h
@@ -510,6 +510,75 @@ static void damon_test_feed_loop_next_input(struct kunit *test)
 			damon_feed_loop_next_input(last_input, 2000));
 }
 
+static void damon_test_set_filters_default_reject(struct kunit *test)
+{
+	struct damos scheme;
+	struct damos_filter *target_filter, *anon_filter;
+
+	INIT_LIST_HEAD(&scheme.filters);
+	INIT_LIST_HEAD(&scheme.ops_filters);
+
+	damos_set_filters_default_reject(&scheme);
+	/*
+	 * No filter is installed.  Allow by default on both core and ops layer
+	 * filtering stages, since there are no filters at all.
+	 */
+	KUNIT_EXPECT_EQ(test, scheme.core_filters_default_reject, false);
+	KUNIT_EXPECT_EQ(test, scheme.ops_filters_default_reject, false);
+
+	target_filter = damos_new_filter(DAMOS_FILTER_TYPE_TARGET, true, true);
+	damos_add_filter(&scheme, target_filter);
+	damos_set_filters_default_reject(&scheme);
+	/*
+	 * A core-handled allow-filter is installed.
+	 * Rejct by default on core layer filtering stage due to the last
+	 * core-layer-filter's behavior.
+	 * Allow by default on ops layer filtering stage due to the absence of
+	 * ops layer filters.
+	 */
+	KUNIT_EXPECT_EQ(test, scheme.core_filters_default_reject, true);
+	KUNIT_EXPECT_EQ(test, scheme.ops_filters_default_reject, false);
+
+	target_filter->allow = false;
+	damos_set_filters_default_reject(&scheme);
+	/*
+	 * A core-handled reject-filter is installed.
+	 * Allow by default on core layer filtering stage due to the last
+	 * core-layer-filter's behavior.
+	 * Allow by default on ops layer filtering stage due to the absence of
+	 * ops layer filters.
+	 */
+	KUNIT_EXPECT_EQ(test, scheme.core_filters_default_reject, false);
+	KUNIT_EXPECT_EQ(test, scheme.ops_filters_default_reject, false);
+
+	anon_filter = damos_new_filter(DAMOS_FILTER_TYPE_ANON, true, true);
+	damos_add_filter(&scheme, anon_filter);
+
+	damos_set_filters_default_reject(&scheme);
+	/*
+	 * A core-handled reject-filter and ops-handled allow-filter are installed.
+	 * Allow by default on core layer filtering stage due to the existence
+	 * of the ops-handled filter.
+	 * Reject by default on ops layer filtering stage due to the last
+	 * ops-layer-filter's behavior.
+	 */
+	KUNIT_EXPECT_EQ(test, scheme.core_filters_default_reject, false);
+	KUNIT_EXPECT_EQ(test, scheme.ops_filters_default_reject, true);
+
+	target_filter->allow = true;
+	damos_set_filters_default_reject(&scheme);
+	/*
+	 * A core-handled allow-filter and ops-handled allow-filter are
+	 * installed.
+	 * Allow by default on core layer filtering stage due to the existence
+	 * of the ops-handled filter.
+	 * Reject by default on ops layer filtering stage due to the last
+	 * ops-layer-filter's behavior.
+	 */
+	KUNIT_EXPECT_EQ(test, scheme.core_filters_default_reject, false);
+	KUNIT_EXPECT_EQ(test, scheme.ops_filters_default_reject, true);
+}
+
 static struct kunit_case damon_test_cases[] = {
 	KUNIT_CASE(damon_test_target),
 	KUNIT_CASE(damon_test_regions),
@@ -527,6 +596,7 @@ static struct kunit_case damon_test_cases[] = {
 	KUNIT_CASE(damos_test_new_filter),
 	KUNIT_CASE(damos_test_filter_out),
 	KUNIT_CASE(damon_test_feed_loop_next_input),
+	KUNIT_CASE(damon_test_set_filters_default_reject),
 	{},
 };
 
-- 
2.39.5

[PATCH 5/6] selftests/damon/_damon_sysfs: read tried regions directories in order

[SeongJae Park]

Kdamond.update_schemes_tried_regions() reads and stores tried regions
information out of address order.  It makes debugging a test failure
difficult.  Change the behavior to do the reading and writing in the
address order.

Signed-off-by: SeongJae Park <sj@kernel.org>
---
 tools/testing/selftests/damon/_damon_sysfs.py | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/tools/testing/selftests/damon/_damon_sysfs.py b/tools/testing/selftests/damon/_damon_sysfs.py
index 6e136dc3df19..1e587e0b1a39 100644
--- a/tools/testing/selftests/damon/_damon_sysfs.py
+++ b/tools/testing/selftests/damon/_damon_sysfs.py
@@ -420,11 +420,16 @@ class Kdamond:
                 tried_regions = []
                 tried_regions_dir = os.path.join(
                         scheme.sysfs_dir(), 'tried_regions')
+                region_indices = []
                 for filename in os.listdir(
                         os.path.join(scheme.sysfs_dir(), 'tried_regions')):
                     tried_region_dir = os.path.join(tried_regions_dir, filename)
                     if not os.path.isdir(tried_region_dir):
                         continue
+                    region_indices.append(int(filename))
+                for region_idx in sorted(region_indices):
+                    tried_region_dir = os.path.join(tried_regions_dir,
+                                                    '%d' % region_idx)
                     region_values = []
                     for f in ['start', 'end', 'nr_accesses', 'age']:
                         content, err = read_file(
-- 
2.39.5