LXR linux/tools/testing/selftests/resctrl/mbm

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Memory Bandwidth Monitoring (MBM) test
   4 *
   5 * Copyright (C) 2018 Intel Corporation
   6 *
   7 * Authors:
   8 *    Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>,
   9 *    Fenghua Yu <fenghua.yu@intel.com>
  10 */
  11#include "resctrl.h"
  12
  13#define RESULT_FILE_NAME        "result_mbm"
  14#define MAX_DIFF_PERCENT        5
  15#define NUM_OF_RUNS             5
  16
  17static int
  18show_bw_info(unsigned long *bw_imc, unsigned long *bw_resc, int span)
  19{
  20        unsigned long avg_bw_imc = 0, avg_bw_resc = 0;
  21        unsigned long sum_bw_imc = 0, sum_bw_resc = 0;
  22        int runs, ret, avg_diff_per;
  23        float avg_diff = 0;
  24
  25        /*
  26         * Discard the first value which is inaccurate due to monitoring setup
  27         * transition phase.
  28         */
  29        for (runs = 1; runs < NUM_OF_RUNS ; runs++) {
  30                sum_bw_imc += bw_imc[runs];
  31                sum_bw_resc += bw_resc[runs];
  32        }
  33
  34        avg_bw_imc = sum_bw_imc / 4;
  35        avg_bw_resc = sum_bw_resc / 4;
  36        avg_diff = (float)labs(avg_bw_resc - avg_bw_imc) / avg_bw_imc;
  37        avg_diff_per = (int)(avg_diff * 100);
  38
  39        ret = avg_diff_per > MAX_DIFF_PERCENT;
  40        ksft_print_msg("%s Check MBM diff within %d%%\n",
  41                       ret ? "Fail:" : "Pass:", MAX_DIFF_PERCENT);
  42        ksft_print_msg("avg_diff_per: %d%%\n", avg_diff_per);
  43        ksft_print_msg("Span (MB): %d\n", span);
  44        ksft_print_msg("avg_bw_imc: %lu\n", avg_bw_imc);
  45        ksft_print_msg("avg_bw_resc: %lu\n", avg_bw_resc);
  46
  47        return ret;
  48}
  49
  50static int check_results(int span)
  51{
  52        unsigned long bw_imc[NUM_OF_RUNS], bw_resc[NUM_OF_RUNS];
  53        char temp[1024], *token_array[8];
  54        char output[] = RESULT_FILE_NAME;
  55        int runs, ret;
  56        FILE *fp;
  57
  58        ksft_print_msg("Checking for pass/fail\n");
  59
  60        fp = fopen(output, "r");
  61        if (!fp) {
  62                perror(output);
  63
  64                return errno;
  65        }
  66
  67        runs = 0;
  68        while (fgets(temp, sizeof(temp), fp)) {
  69                char *token = strtok(temp, ":\t");
  70                int i = 0;
  71
  72                while (token) {
  73                        token_array[i++] = token;
  74                        token = strtok(NULL, ":\t");
  75                }
  76
  77                bw_resc[runs] = strtoul(token_array[5], NULL, 0);
  78                bw_imc[runs] = strtoul(token_array[3], NULL, 0);
  79                runs++;
  80        }
  81
  82        ret = show_bw_info(bw_imc, bw_resc, span);
  83
  84        fclose(fp);
  85
  86        return ret;
  87}
  88
  89static int mbm_setup(int num, ...)
  90{
  91        struct resctrl_val_param *p;
  92        static int num_of_runs;
  93        va_list param;
  94        int ret = 0;
  95
  96        /* Run NUM_OF_RUNS times */
  97        if (num_of_runs++ >= NUM_OF_RUNS)
  98                return -1;
  99
 100        va_start(param, num);
 101        p = va_arg(param, struct resctrl_val_param *);
 102        va_end(param);
 103
 104        /* Set up shemata with 100% allocation on the first run. */
 105        if (num_of_runs == 0)
 106                ret = write_schemata(p->ctrlgrp, "100", p->cpu_no,
 107                                     p->resctrl_val);
 108
 109        return ret;
 110}
 111
 112void mbm_test_cleanup(void)
 113{
 114        remove(RESULT_FILE_NAME);
 115}
 116
 117int mbm_bw_change(int span, int cpu_no, char *bw_report, char **benchmark_cmd)
 118{
 119        struct resctrl_val_param param = {
 120                .resctrl_val    = MBM_STR,
 121                .ctrlgrp        = "c1",
 122                .mongrp         = "m1",
 123                .span           = span,
 124                .cpu_no         = cpu_no,
 125                .mum_resctrlfs  = 1,
 126                .filename       = RESULT_FILE_NAME,
 127                .bw_report      =  bw_report,
 128                .setup          = mbm_setup
 129        };
 130        int ret;
 131
 132        remove(RESULT_FILE_NAME);
 133
 134        ret = resctrl_val(benchmark_cmd, &param);
 135        if (ret)
 136                return ret;
 137
 138        ret = check_results(span);
 139        if (ret)
 140                return ret;
 141
 142        mbm_test_cleanup();
 143
 144        return 0;
 145}
 146