[PATCH 2/4] mm/damon/dbgfs-test: Implement kunit tests for the record feature

[SeongJae Park]

This commit implements kunit tests for the monitoring results record
feture.

Signed-off-by: SeongJae Park <sj@xxxxxxxxxx>
Reviewed-by: Brendan Higgins <brendanhiggins@xxxxxxxxxx>
---
 mm/damon/dbgfs-test.h | 88 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 88 insertions(+)

diff --git a/mm/damon/dbgfs-test.h b/mm/damon/dbgfs-test.h
index 4eddcfa73996..23573ade7ac2 100644
--- a/mm/damon/dbgfs-test.h
+++ b/mm/damon/dbgfs-test.h
@@ -109,9 +109,97 @@ static void damon_dbgfs_test_set_targets(struct kunit *test)
 	dbgfs_destroy_ctx(ctx);
 }
 
+static void damon_dbgfs_test_set_recording(struct kunit *test)
+{
+	struct damon_ctx *ctx = dbgfs_new_ctx();
+	struct dbgfs_recorder *rec = ctx->callback.private;
+	int err;
+
+	err = dbgfs_set_recording(ctx, 42, "foo");
+	KUNIT_EXPECT_EQ(test, err, -EINVAL);
+	dbgfs_set_recording(ctx, 4242, "foo.bar");
+	KUNIT_EXPECT_EQ(test, rec->rbuf_len, 4242u);
+	KUNIT_EXPECT_STREQ(test, rec->rfile_path, "foo.bar");
+	dbgfs_set_recording(ctx, 424242, "foo");
+	KUNIT_EXPECT_EQ(test, rec->rbuf_len, 424242u);
+	KUNIT_EXPECT_STREQ(test, rec->rfile_path, "foo");
+
+	dbgfs_destroy_ctx(ctx);
+}
+
+static void damon_dbgfs_test_write_rbuf(struct kunit *test)
+{
+	struct damon_ctx *ctx = dbgfs_new_ctx();
+	struct dbgfs_recorder *rec = ctx->callback.private;
+	char *data;
+
+	dbgfs_set_recording(ctx, 4242, "damon.data");
+
+	data = "hello";
+	dbgfs_write_rbuf(ctx, data, strnlen(data, 256));
+	KUNIT_EXPECT_EQ(test, rec->rbuf_offset, 5u);
+
+	dbgfs_write_rbuf(ctx, data, 0);
+	KUNIT_EXPECT_EQ(test, rec->rbuf_offset, 5u);
+
+	KUNIT_EXPECT_STREQ(test, (char *)rec->rbuf, data);
+
+	dbgfs_destroy_ctx(ctx);
+}
+
+/*
+ * Test dbgfs_after_aggregation()
+ *
+ * dbgfs sets dbgfs_after_aggregation() as aggregate callback.  It stores the
+ * aggregated monitoring information ('->nr_accesses' of each regions) to the
+ * result buffer.
+ */
+static void damon_dbgfs_test_aggregate(struct kunit *test)
+{
+	struct damon_ctx *ctx = dbgfs_new_ctx();
+	struct dbgfs_recorder *rec = ctx->callback.private;
+	unsigned long target_ids[] = {1, 2, 3};
+	unsigned long saddr[][3] = {{10, 20, 30}, {5, 42, 49}, {13, 33, 55} };
+	unsigned long eaddr[][3] = {{15, 27, 40}, {31, 45, 55}, {23, 44, 66} };
+	unsigned long accesses[][3] = {{42, 95, 84}, {10, 20, 30}, {0, 1, 2} };
+	struct damon_target *t;
+	struct damon_region *r;
+	int it, ir;
+	ssize_t sz, sr, sp;
+
+	/* Make DAMON consider target id as plain number */
+	ctx->primitive.target_valid = NULL;
+	ctx->primitive.cleanup = NULL;
+
+	dbgfs_set_recording(ctx, 4242, "damon.data");
+	damon_set_targets(ctx, target_ids, 3);
+
+	it = 0;
+	damon_for_each_target(t, ctx) {
+		for (ir = 0; ir < 3; ir++) {
+			r = damon_new_region(saddr[it][ir], eaddr[it][ir]);
+			r->nr_accesses = accesses[it][ir];
+			damon_add_region(r, t);
+		}
+		it++;
+	}
+	dbgfs_after_aggregation(ctx);
+
+	/* The aggregated information should be written in the buffer */
+	sr = sizeof(r->ar.start) + sizeof(r->ar.end) + sizeof(r->nr_accesses);
+	sp = sizeof(t->id) + sizeof(unsigned int) + 3 * sr;
+	sz = sizeof(struct timespec64) + sizeof(unsigned int) + 3 * sp;
+	KUNIT_EXPECT_EQ(test, (unsigned int)sz, rec->rbuf_offset);
+
+	damon_destroy_ctx(ctx);
+}
+
 static struct kunit_case damon_test_cases[] = {
 	KUNIT_CASE(damon_dbgfs_test_str_to_target_ids),
 	KUNIT_CASE(damon_dbgfs_test_set_targets),
+	KUNIT_CASE(damon_dbgfs_test_set_recording),
+	KUNIT_CASE(damon_dbgfs_test_write_rbuf),
+	KUNIT_CASE(damon_dbgfs_test_aggregate),
 	{},
 };
 
-- 
2.17.1