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 <akpm@linux-foundation.org>
CC: Rasmus Villemoes <linux@rasmusvillemoes.dk>
CC: David Laight <David.Laight@aculab.com>
Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Suggested-by: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Yury Norov <yury.norov@gmail.com>
This commit is contained in:
Kuan-Wei Chiu 2024-05-02 17:24:42 +08:00 committed by Yury Norov
parent efe3a85eab
commit 0a2c6664e5

View File

@ -5,9 +5,11 @@
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/cleanup.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/printk.h>
#include <linux/slab.h>
/* 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;