linux-stable/lib/dhry_run.c

86 lines
1.7 KiB
C
Raw Normal View History

lib: add Dhrystone benchmark test When working on SoC bring-up, (a full) userspace may not be available, making it hard to benchmark the CPU performance of the system under development. Still, one may want to have a rough idea of the (relative) performance of one or more CPU cores, especially when working on e.g. the clock driver that controls the CPU core clock(s). Hence make the classical Dhrystone 2.1 benchmark available as a Linux kernel test module, based on[1]. When built-in, this benchmark can be run without any userspace present. Parallel runs (run on multiple CPU cores) are supported, just kick the "run" file multiple times. Note that the actual figures depend on the configuration options that control compiler optimization (e.g. CONFIG_CC_OPTIMIZE_FOR_SIZE vs. CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE), and on the compiler options used when building the kernel in general. Hence numbers may differ from those obtained by running similar benchmarks in userspace. [1] https://github.com/qris/dhrystone-deb.git Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Link: https://lkml.kernel.org/r/4d07ad990740a5f1e426ce4566fb514f60ec9bdd.1670509558.git.geert+renesas@glider.be Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Brendan Higgins <brendanhiggins@google.com> Cc: David Gow <davidgow@google.com> [geert+renesas@glider.be: fix uninitialized use of ret] Link: https://lkml.kernel.org/r/alpine.DEB.2.22.394.2212190857310.137329@ramsan.of.borg Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-12-08 14:31:28 +00:00
// 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)
{
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:
if (n >= 0)
pr_info("CPU%u: Dhrystones per Second: %d (%d DMIPS)\n",
smp_processor_id(), 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");