From: Milan Tripkovic <[email protected]> Extend the string benchmarking suite to include memcmp(). Extend the string unit test to include memcmp().
Reported-by: kernel test robot <[email protected]> Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/ Signed-off-by: Milan Tripkovic <[email protected]> --- lib/tests/string_kunit.c | 106 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 106 insertions(+) diff --git a/lib/tests/string_kunit.c b/lib/tests/string_kunit.c index 0819ace5b027..d0bad40a719a 100644 --- a/lib/tests/string_kunit.c +++ b/lib/tests/string_kunit.c @@ -881,6 +881,110 @@ static void string_bench_strrchr(struct kunit *test) STRING_BENCH_BUF(test, buf, len, strrchr, buf, '\0'); } +static void string_test_memcmp(struct kunit *test) +{ + const int max_offset = 16; + const int max_len = 32; + const int buf_size = max_offset + max_len + 32; + u8 *buf1, *buf2; + int i, j, len, k; + + buf1 = kunit_kzalloc(test, buf_size, GFP_KERNEL); + buf2 = kunit_kzalloc(test, buf_size, GFP_KERNEL); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, buf1); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, buf2); + + for (i = 0; i < max_offset; i++) { + for (j = 0; j < max_offset; j++) { + for (len = 0; len <= max_len; len++) { + memset(buf1, 'A', buf_size); + memset(buf2, 'A', buf_size); + KUNIT_EXPECT_EQ_MSG(test, memcmp(buf1 + i, buf2 + j, len), 0, + "Should be equal: i:%d j:%d len:%d", i, j, len); + for (k = 0; k < len; k++) { + memset(buf1, 'A', buf_size); + memset(buf2, 'A', buf_size); + buf2[j + k] = 'B'; + int res = memcmp(buf1 + i, buf2 + j, len); + + KUNIT_EXPECT_NE_MSG(test, res, 0, + "Should detect difference at k:%d (i:%d j:%d len:%d)", + k, i, j, len); + + if (buf1[i + k] < buf2[j + k]) + KUNIT_EXPECT_LT(test, res, 0); + else + KUNIT_EXPECT_GT(test, res, 0); + } + } + } + } +} + +#if IS_ENABLED(CONFIG_STRING_KUNIT_BENCH) +static void string_bench_memcmp(struct kunit *test) +{ + char *buf1, *buf2; + size_t lengths[] = { 1, 7, 8, 16, 32, 64, 128, 512, 1024, 4096}; + int offsets[] = {0, 1, 3, 7}; + const size_t max_len = 4096 + 64; + + buf1 = vmalloc(max_len); + buf2 = vmalloc(max_len); + + if (!buf1 || !buf2) { + vfree(buf1); + vfree(buf2); + kunit_err(test, "vmalloc failed\n"); + return; + } + + memset(buf1, 'A', max_len); + memset(buf2, 'A', max_len); + + for (int i = 0; i < 100000; i++) + (void)memcmp(buf1, buf2, 4096); + + for (int o = 0; o < ARRAY_SIZE(offsets); o++) { + int off = offsets[o]; + + for (int i = 0; i < ARRAY_SIZE(lengths); i++) { + size_t len = lengths[i]; + char *p1 = buf1; + char *p2 = buf2 + off; + + u32 iterations = (len < 512) ? 100000 : 10000; + + for (u32 j = 0; j < iterations; j++) { + (void)memcmp(p1, p2, len); + barrier(); + } + + u64 elapsed = STRING_BENCH(iterations, memcmp, p1, p2, len); + u64 ns_per_call = div_u64(elapsed, iterations); + u64 mbps = len ? div_u64((u64)len * iterations * 1000, + elapsed) : 0; + + if (off == 0) { + kunit_info(test, "bench_memcmp_aligned: len=%-4zu: %llu MB/s (%llu ns/call)\n", + len, mbps, ns_per_call); + } else { + kunit_info(test, "bench_memcmp_unaligned(off=%d): len=%-4zu: %llu MB/s (%llu ns/call)\n", + off, len, mbps, ns_per_call); + } + } + } + + vfree(buf1); + vfree(buf2); +} +#else +static void string_bench_memcmp(struct kunit *test) +{ + kunit_skip(test, "not enabled"); +} +#endif + static struct kunit_case string_test_cases[] = { KUNIT_CASE(string_test_memset16), KUNIT_CASE(string_test_memset32), @@ -910,6 +1014,8 @@ static struct kunit_case string_test_cases[] = { KUNIT_CASE(string_bench_strnlen), KUNIT_CASE(string_bench_strchr), KUNIT_CASE(string_bench_strrchr), + KUNIT_CASE(string_test_memcmp), + KUNIT_CASE_SLOW(string_bench_memcmp), {} }; -- 2.43.0
