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5247e6dbed
Commit20d96b25cc("selftests/resctrl: Fix schemata write error check") exposed a problem in feature detection logic in MBM selftest. If schemata does not support MB:x=x entries, the schemata write to initialize 100% memory bandwidth allocation in mbm_setup() will now fail with -EINVAL due to the error handling corrected by the commit20d96b25cc("selftests/resctrl: Fix schemata write error check"). That commit just uncovers the failed write, it is not wrong itself. If MB:x=x is not supported by schemata, it is safe to assume 100% memory bandwidth is always set. Therefore, the previously ignored error does not make the MBM test itself wrong. Restore the previous behavior of MBM test by checking MB support before attempting to write it into schemata which results in behavior equivalent to ignoring the write error. Fixes:20d96b25cc("selftests/resctrl: Fix schemata write error check") Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
137 lines
2.9 KiB
C
137 lines
2.9 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Memory Bandwidth Monitoring (MBM) test
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*
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* Copyright (C) 2018 Intel Corporation
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*
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* Authors:
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* Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>,
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* Fenghua Yu <fenghua.yu@intel.com>
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*/
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#include "resctrl.h"
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#define RESULT_FILE_NAME "result_mbm"
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#define MAX_DIFF_PERCENT 8
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#define NUM_OF_RUNS 5
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static int
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show_bw_info(unsigned long *bw_imc, unsigned long *bw_resc, size_t span)
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{
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unsigned long avg_bw_imc = 0, avg_bw_resc = 0;
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unsigned long sum_bw_imc = 0, sum_bw_resc = 0;
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int runs, ret, avg_diff_per;
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float avg_diff = 0;
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/*
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* Discard the first value which is inaccurate due to monitoring setup
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* transition phase.
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*/
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for (runs = 1; runs < NUM_OF_RUNS ; runs++) {
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sum_bw_imc += bw_imc[runs];
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sum_bw_resc += bw_resc[runs];
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}
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avg_bw_imc = sum_bw_imc / 4;
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avg_bw_resc = sum_bw_resc / 4;
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avg_diff = (float)labs(avg_bw_resc - avg_bw_imc) / avg_bw_imc;
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avg_diff_per = (int)(avg_diff * 100);
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ret = avg_diff_per > MAX_DIFF_PERCENT;
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ksft_print_msg("%s Check MBM diff within %d%%\n",
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ret ? "Fail:" : "Pass:", MAX_DIFF_PERCENT);
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ksft_print_msg("avg_diff_per: %d%%\n", avg_diff_per);
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ksft_print_msg("Span (MB): %zu\n", span / MB);
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ksft_print_msg("avg_bw_imc: %lu\n", avg_bw_imc);
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ksft_print_msg("avg_bw_resc: %lu\n", avg_bw_resc);
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return ret;
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}
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static int check_results(size_t span)
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{
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unsigned long bw_imc[NUM_OF_RUNS], bw_resc[NUM_OF_RUNS];
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char temp[1024], *token_array[8];
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char output[] = RESULT_FILE_NAME;
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int runs, ret;
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FILE *fp;
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ksft_print_msg("Checking for pass/fail\n");
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fp = fopen(output, "r");
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if (!fp) {
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perror(output);
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return errno;
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}
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runs = 0;
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while (fgets(temp, sizeof(temp), fp)) {
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char *token = strtok(temp, ":\t");
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int i = 0;
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while (token) {
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token_array[i++] = token;
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token = strtok(NULL, ":\t");
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}
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bw_resc[runs] = strtoul(token_array[5], NULL, 0);
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bw_imc[runs] = strtoul(token_array[3], NULL, 0);
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runs++;
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}
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ret = show_bw_info(bw_imc, bw_resc, span);
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fclose(fp);
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return ret;
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}
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static int mbm_setup(struct resctrl_val_param *p)
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{
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int ret = 0;
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/* Run NUM_OF_RUNS times */
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if (p->num_of_runs >= NUM_OF_RUNS)
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return END_OF_TESTS;
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/* Set up shemata with 100% allocation on the first run. */
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if (p->num_of_runs == 0 && validate_resctrl_feature_request("MB", NULL))
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ret = write_schemata(p->ctrlgrp, "100", p->cpu_no,
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p->resctrl_val);
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p->num_of_runs++;
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return ret;
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}
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void mbm_test_cleanup(void)
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{
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remove(RESULT_FILE_NAME);
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}
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int mbm_bw_change(int cpu_no, const char * const *benchmark_cmd)
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{
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struct resctrl_val_param param = {
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.resctrl_val = MBM_STR,
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.ctrlgrp = "c1",
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.mongrp = "m1",
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.cpu_no = cpu_no,
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.filename = RESULT_FILE_NAME,
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.bw_report = "reads",
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.setup = mbm_setup
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};
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int ret;
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remove(RESULT_FILE_NAME);
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ret = resctrl_val(benchmark_cmd, ¶m);
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if (ret)
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goto out;
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ret = check_results(DEFAULT_SPAN);
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out:
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mbm_test_cleanup();
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return ret;
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}
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