@@ -554,6 +554,57 @@ static void crc32c_flip_range_test(struct kunit *test)
}
}
+/*
+ * Benchmark crc32c_flip_range vs full crc32c recomputation
+ */
+static void crc32c_flip_range_benchmark(struct kunit *test)
+{
+ static const size_t bitmap_sizes[] = {
+ 1024, 2048, 4096, 8192, 16384, 32768, 65536,
+ };
+ size_t i, j, num_iters, buflen, total_bits;
+ volatile u32 crc;
+ u64 t_flip, t_full;
+ u8 *buf;
+
+ if (!IS_ENABLED(CONFIG_CRC_BENCHMARK))
+ kunit_skip(test, "not enabled");
+
+ buf = kunit_kzalloc(test, 65536, GFP_KERNEL);
+ KUNIT_ASSERT_NOT_NULL(test, buf);
+
+ for (i = 0; i < ARRAY_SIZE(bitmap_sizes); i++) {
+ buflen = bitmap_sizes[i];
+ total_bits = buflen * 8;
+ num_iters = 10000000 / (buflen + 128);
+
+ /* Benchmark crc32c_flip_range */
+ crc = crc32c(0, buf, buflen);
+ preempt_disable();
+ t_flip = ktime_get_ns();
+ for (j = 0; j < num_iters; j++)
+ crc = crc32c_flip_range(crc, total_bits, 100, 100);
+ t_flip = ktime_get_ns() - t_flip;
+ preempt_enable();
+
+ /* Benchmark full crc32c recomputation */
+ preempt_disable();
+ t_full = ktime_get_ns();
+ for (j = 0; j < num_iters; j++)
+ crc = crc32c(0, buf, buflen);
+ t_full = ktime_get_ns() - t_full;
+ preempt_enable();
+
+ kunit_info(test,
+ "bitmap=%zu: flip_range=%llu ns, full_crc=%llu ns, speedup=%llu.%01llux\n",
+ buflen,
+ div64_u64(t_flip, num_iters),
+ div64_u64(t_full, num_iters),
+ div64_u64(t_full * 10, t_flip ? t_flip : 1) / 10,
+ div64_u64(t_full * 10, t_flip ? t_flip : 1) % 10);
+ }
+}
+
static struct kunit_case crc_test_cases[] = {
#if IS_REACHABLE(CONFIG_CRC7)
KUNIT_CASE(crc7_be_test),
@@ -575,6 +626,7 @@ static struct kunit_case crc_test_cases[] = {
KUNIT_CASE(crc32c_test),
KUNIT_CASE(crc32c_benchmark),
KUNIT_CASE(crc32c_flip_range_test),
+ KUNIT_CASE(crc32c_flip_range_benchmark),
#endif
#if IS_REACHABLE(CONFIG_CRC64)
KUNIT_CASE(crc64_be_test),
Add a kunit benchmark comparing crc32c_flip_range() against full crc32c recomputation across bitmap sizes from 1KB to 64KB. The benchmark reports per-call latency in nanoseconds and the speedup ratio. Sample results (x86_64, Intel(R) Xeon(R) Platinum 8331C): bitmap=1024: flip_range=48 ns, full_crc=45 ns, speedup=0.9x bitmap=2048: flip_range=53 ns, full_crc=88 ns, speedup=1.6x bitmap=4096: flip_range=57 ns, full_crc=182 ns, speedup=3.1x bitmap=8192: flip_range=63 ns, full_crc=357 ns, speedup=5.6x bitmap=16384: flip_range=68 ns, full_crc=709 ns, speedup=10.3x bitmap=32768: flip_range=73 ns, full_crc=1421 ns, speedup=19.3x bitmap=65536: flip_range=78 ns, full_crc=2853 ns, speedup=36.3x Signed-off-by: Baokun Li <libaokun@linux.alibaba.com> --- lib/crc/tests/crc_kunit.c | 52 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 52 insertions(+)