mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-03 17:40:04 +00:00
![Geert Uytterhoeven](/assets/img/avatar_default.png)
When running the in-kernel Dhrystone benchmark with
CONFIG_DEBUG_PREEMPT=y:
BUG: using smp_processor_id() in preemptible [00000000] code: bash/938
Fix this by not using smp_processor_id() directly, but instead wrapping
the whole benchmark inside a get_cpu()/put_cpu() pair. This makes sure
the whole benchmark is run on the same CPU core, and the reported values
are consistent.
Link: https://lkml.kernel.org/r/b0d29932bb24ad82cea7f821e295c898e9657be0.1678890070.git.geert+renesas@glider.be
Fixes: d5528cc168
("lib: add Dhrystone benchmark test")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reported-by: Tobias Klausmann <klausman@schwarzvogel.de>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=217179
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
87 lines
1.7 KiB
C
87 lines
1.7 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* Dhrystone benchmark test module
|
|
*
|
|
* Copyright (C) 2022 Glider bv
|
|
*/
|
|
|
|
#include "dhry.h"
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/moduleparam.h>
|
|
#include <linux/mutex.h>
|
|
#include <linux/smp.h>
|
|
|
|
#define DHRY_VAX 1757
|
|
|
|
static int dhry_run_set(const char *val, const struct kernel_param *kp);
|
|
static const struct kernel_param_ops run_ops = {
|
|
.flags = KERNEL_PARAM_OPS_FL_NOARG,
|
|
.set = dhry_run_set,
|
|
};
|
|
static bool dhry_run;
|
|
module_param_cb(run, &run_ops, &dhry_run, 0200);
|
|
MODULE_PARM_DESC(run, "Run the test (default: false)");
|
|
|
|
static int iterations = -1;
|
|
module_param(iterations, int, 0644);
|
|
MODULE_PARM_DESC(iterations,
|
|
"Number of iterations through the benchmark (default: auto)");
|
|
|
|
static void dhry_benchmark(void)
|
|
{
|
|
unsigned int cpu = get_cpu();
|
|
int i, n;
|
|
|
|
if (iterations > 0) {
|
|
n = dhry(iterations);
|
|
goto report;
|
|
}
|
|
|
|
for (i = DHRY_VAX; i > 0; i <<= 1) {
|
|
n = dhry(i);
|
|
if (n != -EAGAIN)
|
|
break;
|
|
}
|
|
|
|
report:
|
|
put_cpu();
|
|
if (n >= 0)
|
|
pr_info("CPU%u: Dhrystones per Second: %d (%d DMIPS)\n", cpu,
|
|
n, n / DHRY_VAX);
|
|
else if (n == -EAGAIN)
|
|
pr_err("Please increase the number of iterations\n");
|
|
else
|
|
pr_err("Dhrystone benchmark failed error %pe\n", ERR_PTR(n));
|
|
}
|
|
|
|
static int dhry_run_set(const char *val, const struct kernel_param *kp)
|
|
{
|
|
int ret;
|
|
|
|
if (val) {
|
|
ret = param_set_bool(val, kp);
|
|
if (ret)
|
|
return ret;
|
|
} else {
|
|
dhry_run = true;
|
|
}
|
|
|
|
if (dhry_run && system_state == SYSTEM_RUNNING)
|
|
dhry_benchmark();
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int __init dhry_init(void)
|
|
{
|
|
if (dhry_run)
|
|
dhry_benchmark();
|
|
|
|
return 0;
|
|
}
|
|
module_init(dhry_init);
|
|
|
|
MODULE_AUTHOR("Geert Uytterhoeven <geert+renesas@glider.be>");
|
|
MODULE_LICENSE("GPL");
|