lib/string_kunit: add performance benchmark for strlen()

Introduce a benchmarking framework to the string_kunit test suite to
measure the execution efficiency of string functions.

The implementation is inspired by crc_benchmark(), measuring throughput
(MB/s) and latency (ns/call) across a range of string lengths. It
includes a warm-up phase, disables preemption during measurement, and
uses a fixed seed for reproducible results.

This framework allows for comparing different implementations (e.g.,
generic C vs. architecture-optimized assembly) within the KUnit
environment.

Initially, provide a benchmark for strlen().

Suggested-by: Andy Shevchenko <andy@kernel.org>
Suggested-by: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Feng Jiang <jiangfeng@kylinos.cn>
Reviewed-by: Kees Cook <kees@kernel.org>
Link: https://patch.msgid.link/20260130025018.172925-5-jiangfeng@kylinos.cn
[pjw@kernel.org: fixed a checkpatch issue]
Signed-off-by: Paul Walmsley <pjw@kernel.org>

0 files changed, 0 insertions, 0 deletions