mm/damon/tests/core-kunit: add a test for damon_commit_ctx()

Patch series "mm/damon: test and document power-of-2 min_region_sz
requirement".

Since commit c80f46ac228b ("mm/damon/core: disallow non-power of two
min_region_sz"), min_region_sz is always restricted to be a power of two.
Add a kunit test to confirm the functionality.  Also, the change adds a
restriction to addr_unit parameter.  Clarify it on the document.

This patch (of 2):

Add a kunit test for confirming the change that is made on commit
c80f46ac228b ("mm/damon/core: disallow non-power of two min_region_sz")
functions as expected.

Link: https://lkml.kernel.org/r/20260307194222.202075-2-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Brendan Higgins <brendan.higgins@linux.dev>
Cc: David Gow <davidgow@google.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: SeongJae Park <sj@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/damon/tests/core-kunit.h b/mm/damon/tests/core-kunit.h
index fcc1336b234c0b2ca1c27a2050a5b164790798b9..2289f9e4610c0331002ab2011045f73b6dec960a 100644 (file)
--- a/mm/damon/tests/core-kunit.h
+++ b/mm/damon/tests/core-kunit.h
@@ -1057,6 +1057,27 @@ static void damon_test_commit_target_regions(struct kunit *test)
                        (unsigned long[][2]) {{3, 8}, {8, 10}}, 2);
 }
 
+static void damon_test_commit_ctx(struct kunit *test)
+{
+       struct damon_ctx *src, *dst;
+
+       src = damon_new_ctx();
+       if (!src)
+               kunit_skip(test, "src alloc fail");
+       dst = damon_new_ctx();
+       if (!dst) {
+               damon_destroy_ctx(src);
+               kunit_skip(test, "dst alloc fail");
+       }
+       /* Only power of two min_region_sz is allowed. */
+       src->min_region_sz = 4096;
+       KUNIT_EXPECT_EQ(test, damon_commit_ctx(dst, src), 0);
+       src->min_region_sz = 4095;
+       KUNIT_EXPECT_EQ(test, damon_commit_ctx(dst, src), -EINVAL);
+       damon_destroy_ctx(src);
+       damon_destroy_ctx(dst);
+}
+
 static void damos_test_filter_out(struct kunit *test)
 {
        struct damon_target *t;
@@ -1313,6 +1334,7 @@ static struct kunit_case damon_test_cases[] = {
        KUNIT_CASE(damos_test_commit_pageout),
        KUNIT_CASE(damos_test_commit_migrate_hot),
        KUNIT_CASE(damon_test_commit_target_regions),
+       KUNIT_CASE(damon_test_commit_ctx),
        KUNIT_CASE(damos_test_filter_out),
        KUNIT_CASE(damon_test_feed_loop_next_input),
        KUNIT_CASE(damon_test_set_filters_default_reject),