Hi Mike

From: "Mike Rapoport (Microsoft)" <rppt@kernel.org>

Currently khugepaged decides if a test can run using TEST() macro that
checks what mem_ops and collapse_context are set by the command line
arguments.

For better compatibility with ksefltest framework, add an array of 'struct
test_case's and redefine TEST() macro to conditionally add enabled tests to
that array.

Then execute the enabled test by looping the test_case's array.

Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
---
 tools/testing/selftests/mm/khugepaged.c | 43 +++++++++++++++++++++----
 1 file changed, 36 insertions(+), 7 deletions(-)

diff --git a/tools/testing/selftests/mm/khugepaged.c b/tools/testing/selftests/mm/khugepaged.c
index e6fb01ca44ed..1cdc5918d20d 100644
--- a/tools/testing/selftests/mm/khugepaged.c
+++ b/tools/testing/selftests/mm/khugepaged.c
@@ -1161,6 +1161,34 @@ static void parse_test_type(int argc, char **argv)
 	get_finfo(argv[1]);
 }
 
+typedef void (*test_fn)(struct collapse_context *c, struct mem_ops *ops);
+
+struct test_case {
+	struct collapse_context *ctx;
+	struct mem_ops *ops;
+	const char *desc;
+	test_fn fn;
+};
+
+#define MAX_TEST_CASES 45

I see 48 tests in khugepaged.c, and running khugepaged all:all results in the error below. Should MAX_TEST_CASES be updated to 48 instead?

./khugepaged all:all .
TAP version 13
# Save THP and khugepaged settings... OK
Bail out! MAX_ADD_CASES is too small
# Totals: pass:0 fail:0 xfail:0 xpass:0 skip:0 error:0
# Restore THP and khugepaged settings... OK
# Totals: pass:0 fail:0 xfail:0 xpass:0 skip:0 error:0

+static struct test_case test_cases[MAX_TEST_CASES];
+static int nr_test_cases;
+
+#define TEST(t, c, o) do {						\
+	if (c && o) {							\
+		if (nr_test_cases >= MAX_TEST_CASES) {			\

I had a small question—since the number of tests is fixed, would this check still be necessary?

+			printf("MAX_ADD_CASES is too small\n");		\
+			exit(EXIT_FAILURE);				\
+		}							\
+		test_cases[nr_test_cases++] = (struct test_case){	\
+			.ctx	= c,					\
+			.ops	= o,					\
+			.desc	= #t,					\
+			.fn	= t,					\
+		};							\
+	}								\
+	} while (0)
+
 int main(int argc, char **argv)
 {
 	int hpage_pmd_order;
@@ -1216,13 +1244,6 @@ int main(int argc, char **argv)
 
 	alloc_at_fault();
 
-#define TEST(t, c, o) do { \
-	if (c && o) { \
-		printf("\nRun test: " #t " (%s:%s)\n", c->name, o->name); \
-		t(c, o); \
-	} \
-	} while (0)
-
 	TEST(collapse_full, khugepaged_context, anon_ops);
 	TEST(collapse_full, khugepaged_context, file_ops);
 	TEST(collapse_full, khugepaged_context, shmem_ops);
@@ -1284,5 +1305,13 @@ int main(int argc, char **argv)
 	TEST(madvise_retracted_page_tables, madvise_context, file_ops);
 	TEST(madvise_retracted_page_tables, madvise_context, shmem_ops);
 
+	for (int i = 0; i < nr_test_cases; i++) {
+		struct test_case *t = &test_cases[i];
+
+		exit_status = KSFT_PASS;
+		printf("\nRun test: %s: (%s:%s)\n", t->desc, t->ctx->name, t->ops->name);
+		t->fn(t->ctx, t->ops);
+	}
+
 	restore_settings(0);
 }

-Donet