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 <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        8
  15 #define NUM_OF_RUNS             5
  16
  17 static int
  18 show_bw_info(unsigned long *bw_imc, unsigned long *bw_resc, size_t 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): %zu\n", span / MB);
  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(size_t 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                 ksft_perror(output);
  63
  64                 return -1;
  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(const struct resctrl_test *test,
  90                      const struct user_params *uparams,
  91                      struct resctrl_val_param *p)
  92 {
  93         int ret = 0;
  94
  95         /* Run NUM_OF_RUNS times */
  96         if (p->num_of_runs >= NUM_OF_RUNS)
  97                 return END_OF_TESTS;
  98
  99         /* Set up shemata with 100% allocation on the first run. */
 100         if (p->num_of_runs == 0 && resctrl_resource_exists("MB"))
 101                 ret = write_schemata(p->ctrlgrp, "100", uparams->cpu, test->resource);
 102
 103         p->num_of_runs++;
 104
 105         return ret;
 106 }
 107
 108 void mbm_test_cleanup(void)
 109 {
 110         remove(RESULT_FILE_NAME);
 111 }
 112
 113 static int mbm_run_test(const struct resctrl_test *test, const struct user_params *uparams)
 114 {
 115         struct resctrl_val_param param = {
 116                 .resctrl_val    = MBM_STR,
 117                 .ctrlgrp        = "c1",
 118                 .mongrp         = "m1",
 119                 .filename       = RESULT_FILE_NAME,
 120                 .bw_report      = "reads",
 121                 .setup          = mbm_setup
 122         };
 123         int ret;
 124
 125         remove(RESULT_FILE_NAME);
 126
 127         ret = resctrl_val(test, uparams, uparams->benchmark_cmd, &param);
 128         if (ret)
 129                 goto out;
 130
 131         ret = check_results(DEFAULT_SPAN);
 132         if (ret && (get_vendor() == ARCH_INTEL))
 133                 ksft_print_msg("Intel MBM may be inaccurate when Sub-NUMA Clustering is enabled. Check BIOS configuration.\n");
 134
 135 out:
 136         mbm_test_cleanup();
 137
 138         return ret;
 139 }
 140
 141 static bool mbm_feature_check(const struct resctrl_test *test)
 142 {
 143         return resctrl_mon_feature_exists("L3_MON", "mbm_total_bytes") &&
 144                resctrl_mon_feature_exists("L3_MON", "mbm_local_bytes");
 145 }
 146
 147 struct resctrl_test mbm_test = {
 148         .name = "MBM",
 149         .resource = "MB",
 150         .vendor_specific = ARCH_INTEL,
 151         .feature_check = mbm_feature_check,
 152         .run_test = mbm_run_test,
 153 };