[PATCH v3 5/8] lib/string_kunit: extend benchmarks to strnlen and chr searches

[Feng Jiang]

Extend the string benchmarking suite to include strnlen(), strchr(),
and strrchr().

For character search functions (strchr and strrchr), the benchmark
targets the null terminator. This ensures the entire string is scanned,
providing a consistent measure of full-length processing efficiency
comparable to strlen().

Suggested-by: Andy Shevchenko <andy at kernel.org>
Suggested-by: Eric Biggers <ebiggers at kernel.org>
Tested-by: Joel Stanley <joel at jms.id.au>
Signed-off-by: Feng Jiang <jiangfeng at kylinos.cn>
---
 lib/tests/string_kunit.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/lib/tests/string_kunit.c b/lib/tests/string_kunit.c
index e20e924d1c67..9d76777ad753 100644
--- a/lib/tests/string_kunit.c
+++ b/lib/tests/string_kunit.c
@@ -850,6 +850,21 @@ static void string_bench_strlen(struct kunit *test)
 	STRING_BENCH_BUF(test, buf, len, strlen, buf);
 }
 
+static void string_bench_strnlen(struct kunit *test)
+{
+	STRING_BENCH_BUF(test, buf, len, strnlen, buf, len);
+}
+
+static void string_bench_strchr(struct kunit *test)
+{
+	STRING_BENCH_BUF(test, buf, len, strchr, buf, '\0');
+}
+
+static void string_bench_strrchr(struct kunit *test)
+{
+	STRING_BENCH_BUF(test, buf, len, strrchr, buf, '\0');
+}
+
 static struct kunit_case string_test_cases[] = {
 	KUNIT_CASE(string_test_memset16),
 	KUNIT_CASE(string_test_memset32),
@@ -876,6 +891,9 @@ static struct kunit_case string_test_cases[] = {
 	KUNIT_CASE(string_test_memtostr),
 	KUNIT_CASE(string_test_strends),
 	KUNIT_CASE(string_bench_strlen),
+	KUNIT_CASE(string_bench_strnlen),
+	KUNIT_CASE(string_bench_strchr),
+	KUNIT_CASE(string_bench_strrchr),
 	{}
 };
 
-- 
2.25.1