linux/tools/testing/selftests/resctrl/mbm_test.c
Fenghua Yu f1dd71982d selftests/resctrl: Skip the test if requested resctrl feature is not supported
There could be two reasons why a resctrl feature might not be enabled on
the platform
1. H/W might not support the feature
2. Even if the H/W supports it, the user might have disabled the feature
   through kernel command line arguments

Hence, any resctrl unit test (like cmt, cat, mbm and mba) before starting
the test will first check if the feature is enabled on the platform or not.
If the feature isn't enabled, then the test returns with an error status.
For example, if MBA isn't supported on a platform and if the user tries to
run MBA, the output will look like this

ok mounting resctrl to "/sys/fs/resctrl"
not ok MBA: schemata change

But, not supporting a feature isn't a test failure. So, instead of treating
it as an error, use the SKIP directive of the TAP protocol. With the
change, the output will look as below

ok MBA # SKIP Hardware does not support MBA or MBA is disabled

Suggested-by: Reinette Chatre <reinette.chatre@intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2021-04-02 13:58:20 -06:00

146 lines
3.0 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Memory Bandwidth Monitoring (MBM) test
*
* Copyright (C) 2018 Intel Corporation
*
* Authors:
* Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>,
* Fenghua Yu <fenghua.yu@intel.com>
*/
#include "resctrl.h"
#define RESULT_FILE_NAME "result_mbm"
#define MAX_DIFF_PERCENT 5
#define NUM_OF_RUNS 5
static int
show_bw_info(unsigned long *bw_imc, unsigned long *bw_resc, int span)
{
unsigned long avg_bw_imc = 0, avg_bw_resc = 0;
unsigned long sum_bw_imc = 0, sum_bw_resc = 0;
int runs, ret, avg_diff_per;
float avg_diff = 0;
/*
* Discard the first value which is inaccurate due to monitoring setup
* transition phase.
*/
for (runs = 1; runs < NUM_OF_RUNS ; runs++) {
sum_bw_imc += bw_imc[runs];
sum_bw_resc += bw_resc[runs];
}
avg_bw_imc = sum_bw_imc / 4;
avg_bw_resc = sum_bw_resc / 4;
avg_diff = (float)labs(avg_bw_resc - avg_bw_imc) / avg_bw_imc;
avg_diff_per = (int)(avg_diff * 100);
ret = avg_diff_per > MAX_DIFF_PERCENT;
ksft_print_msg("%s MBM: diff within %d%%\n",
ret ? "Fail:" : "Pass:", MAX_DIFF_PERCENT);
ksft_print_msg("avg_diff_per: %d%%\n", avg_diff_per);
ksft_print_msg("Span (MB): %d\n", span);
ksft_print_msg("avg_bw_imc: %lu\n", avg_bw_imc);
ksft_print_msg("avg_bw_resc: %lu\n", avg_bw_resc);
return ret;
}
static int check_results(int span)
{
unsigned long bw_imc[NUM_OF_RUNS], bw_resc[NUM_OF_RUNS];
char temp[1024], *token_array[8];
char output[] = RESULT_FILE_NAME;
int runs, ret;
FILE *fp;
ksft_print_msg("Checking for pass/fail\n");
fp = fopen(output, "r");
if (!fp) {
perror(output);
return errno;
}
runs = 0;
while (fgets(temp, sizeof(temp), fp)) {
char *token = strtok(temp, ":\t");
int i = 0;
while (token) {
token_array[i++] = token;
token = strtok(NULL, ":\t");
}
bw_resc[runs] = strtoul(token_array[5], NULL, 0);
bw_imc[runs] = strtoul(token_array[3], NULL, 0);
runs++;
}
ret = show_bw_info(bw_imc, bw_resc, span);
fclose(fp);
return ret;
}
static int mbm_setup(int num, ...)
{
struct resctrl_val_param *p;
static int num_of_runs;
va_list param;
int ret = 0;
/* Run NUM_OF_RUNS times */
if (num_of_runs++ >= NUM_OF_RUNS)
return -1;
va_start(param, num);
p = va_arg(param, struct resctrl_val_param *);
va_end(param);
/* Set up shemata with 100% allocation on the first run. */
if (num_of_runs == 0)
ret = write_schemata(p->ctrlgrp, "100", p->cpu_no,
p->resctrl_val);
return ret;
}
void mbm_test_cleanup(void)
{
remove(RESULT_FILE_NAME);
}
int mbm_bw_change(int span, int cpu_no, char *bw_report, char **benchmark_cmd)
{
struct resctrl_val_param param = {
.resctrl_val = MBM_STR,
.ctrlgrp = "c1",
.mongrp = "m1",
.span = span,
.cpu_no = cpu_no,
.mum_resctrlfs = 1,
.filename = RESULT_FILE_NAME,
.bw_report = bw_report,
.setup = mbm_setup
};
int ret;
remove(RESULT_FILE_NAME);
ret = resctrl_val(benchmark_cmd, &param);
if (ret)
return ret;
ret = check_results(span);
if (ret)
return ret;
mbm_test_cleanup();
return 0;
}