tools/testing/selftests/resctrl/mbm_test.c

   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 <[email protected]>,
   9  *    Fenghua Yu <[email protected]>
  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
  17 static int
  18 show_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
  50 static 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
  89 static int mbm_setup(int num, ...)
  90 {
  91         struct resctrl_val_param *p;
  92         va_list param;
  93         int ret = 0;
  94
  95         va_start(param, num);
  96         p = va_arg(param, struct resctrl_val_param *);
  97         va_end(param);
  98
  99         /* Run NUM_OF_RUNS times */
 100         if (p->num_of_runs >= NUM_OF_RUNS)
 101                 return END_OF_TESTS;
 102
 103         /* Set up shemata with 100% allocation on the first run. */
 104         if (p->num_of_runs == 0)
 105                 ret = write_schemata(p->ctrlgrp, "100", p->cpu_no,
 106                                      p->resctrl_val);
 107
 108         p->num_of_runs++;
 109
 110         return ret;
 111 }
 112
 113 void mbm_test_cleanup(void)
 114 {
 115         remove(RESULT_FILE_NAME);
 116 }
 117
 118 int mbm_bw_change(int span, int cpu_no, char *bw_report, char **benchmark_cmd)
 119 {
 120         struct resctrl_val_param param = {
 121                 .resctrl_val    = MBM_STR,
 122                 .ctrlgrp        = "c1",
 123                 .mongrp         = "m1",
 124                 .span           = span,
 125                 .cpu_no         = cpu_no,
 126                 .mum_resctrlfs  = true,
 127                 .filename       = RESULT_FILE_NAME,
 128                 .bw_report      =  bw_report,
 129                 .setup          = mbm_setup
 130         };
 131         int ret;
 132
 133         remove(RESULT_FILE_NAME);
 134
 135         ret = resctrl_val(benchmark_cmd, &param);
 136         if (ret)
 137                 goto out;
 138
 139         ret = check_results(span);
 140
 141 out:
 142         mbm_test_cleanup();
 143
 144         return ret;
 145 }