From 0a2c6664e56f0dff7535c3d3d9a6174279e18acc Mon Sep 17 00:00:00 2001 From: Kuan-Wei Chiu Date: Thu, 2 May 2024 17:24:42 +0800 Subject: lib/test_bitops: Add benchmark test for fns() Introduce a benchmark test for the fns(). It measures the total time taken by fns() to process 10,000 test data generated using get_random_bytes() for each n in the range [0, BITS_PER_LONG). example: test_bitops: fns: 7637268 ns CC: Andrew Morton CC: Rasmus Villemoes CC: David Laight Signed-off-by: Kuan-Wei Chiu Suggested-by: Yury Norov Signed-off-by: Yury Norov --- lib/test_bitops.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) (limited to 'lib') diff --git a/lib/test_bitops.c b/lib/test_bitops.c index 3b7bcbee84db..55669624bb28 100644 --- a/lib/test_bitops.c +++ b/lib/test_bitops.c @@ -5,9 +5,11 @@ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt +#include #include #include #include +#include /* a tiny module only meant to test * @@ -50,6 +52,30 @@ static unsigned long order_comb_long[][2] = { }; #endif +static int __init test_fns(void) +{ + static volatile __always_used unsigned long tmp __initdata; + unsigned long *buf __free(kfree) = NULL; + unsigned int i, n; + ktime_t time; + + buf = kmalloc_array(10000, sizeof(unsigned long), GFP_KERNEL); + if (!buf) + return -ENOMEM; + + get_random_bytes(buf, 10000 * sizeof(unsigned long)); + time = ktime_get(); + + for (n = 0; n < BITS_PER_LONG; n++) + for (i = 0; i < 10000; i++) + tmp = fns(buf[i], n); + + time = ktime_get() - time; + pr_err("fns: %18llu ns\n", time); + + return 0; +} + static int __init test_bitops_startup(void) { int i, bit_set; @@ -94,6 +120,8 @@ static int __init test_bitops_startup(void) if (bit_set != BITOPS_LAST) pr_err("ERROR: FOUND SET BIT %d\n", bit_set); + test_fns(); + pr_info("Completed bitops test\n"); return 0; -- cgit v1.2.3-58-ga151