tools/testing/selftests/resctrl/mba_test.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Memory Bandwidth Allocation (MBA) 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_mba"
  14 #define NUM_OF_RUNS             5
  15 #define MAX_DIFF_PERCENT        5
  16 #define ALLOCATION_MAX          100
  17 #define ALLOCATION_MIN          10
  18 #define ALLOCATION_STEP         10
  19
  20 /*
  21  * Change schemata percentage from 100 to 10%. Write schemata to specified
  22  * con_mon grp, mon_grp in resctrl FS.
  23  * For each allocation, run 5 times in order to get average values.
  24  */
  25 static int mba_setup(int num, ...)
  26 {
  27         static int runs_per_allocation, allocation = 100;
  28         struct resctrl_val_param *p;
  29         char allocation_str[64];
  30         va_list param;
  31
  32         va_start(param, num);
  33         p = va_arg(param, struct resctrl_val_param *);
  34         va_end(param);
  35
  36         if (runs_per_allocation >= NUM_OF_RUNS)
  37                 runs_per_allocation = 0;
  38
  39         /* Only set up schemata once every NUM_OF_RUNS of allocations */
  40         if (runs_per_allocation++ != 0)
  41                 return 0;
  42
  43         if (allocation < ALLOCATION_MIN || allocation > ALLOCATION_MAX)
  44                 return -1;
  45
  46         sprintf(allocation_str, "%d", allocation);
  47
  48         write_schemata(p->ctrlgrp, allocation_str, p->cpu_no, p->resctrl_val);
  49         allocation -= ALLOCATION_STEP;
  50
  51         return 0;
  52 }
  53
  54 static void show_mba_info(unsigned long *bw_imc, unsigned long *bw_resc)
  55 {
  56         int allocation, runs;
  57         bool failed = false;
  58
  59         ksft_print_msg("Results are displayed in (MB)\n");
  60         /* Memory bandwidth from 100% down to 10% */
  61         for (allocation = 0; allocation < ALLOCATION_MAX / ALLOCATION_STEP;
  62              allocation++) {
  63                 unsigned long avg_bw_imc, avg_bw_resc;
  64                 unsigned long sum_bw_imc = 0, sum_bw_resc = 0;
  65                 int avg_diff_per;
  66                 float avg_diff;
  67
  68                 /*
  69                  * The first run is discarded due to inaccurate value from
  70                  * phase transition.
  71                  */
  72                 for (runs = NUM_OF_RUNS * allocation + 1;
  73                      runs < NUM_OF_RUNS * allocation + NUM_OF_RUNS ; runs++) {
  74                         sum_bw_imc += bw_imc[runs];
  75                         sum_bw_resc += bw_resc[runs];
  76                 }
  77
  78                 avg_bw_imc = sum_bw_imc / (NUM_OF_RUNS - 1);
  79                 avg_bw_resc = sum_bw_resc / (NUM_OF_RUNS - 1);
  80                 avg_diff = (float)labs(avg_bw_resc - avg_bw_imc) / avg_bw_imc;
  81                 avg_diff_per = (int)(avg_diff * 100);
  82
  83                 ksft_print_msg("%s MBA: diff within %d%% for schemata %u\n",
  84                                avg_diff_per > MAX_DIFF_PERCENT ?
  85                                "Fail:" : "Pass:",
  86                                MAX_DIFF_PERCENT,
  87                                ALLOCATION_MAX - ALLOCATION_STEP * allocation);
  88
  89                 ksft_print_msg("avg_diff_per: %d%%\n", avg_diff_per);
  90                 ksft_print_msg("avg_bw_imc: %lu\n", avg_bw_imc);
  91                 ksft_print_msg("avg_bw_resc: %lu\n", avg_bw_resc);
  92                 if (avg_diff_per > MAX_DIFF_PERCENT)
  93                         failed = true;
  94         }
  95
  96         ksft_print_msg("%s schemata change using MBA\n",
  97                        failed ? "Fail:" : "Pass:");
  98         if (failed)
  99                 ksft_print_msg("At least one test failed");
 100 }
 101
 102 static int check_results(void)
 103 {
 104         char *token_array[8], output[] = RESULT_FILE_NAME, temp[512];
 105         unsigned long bw_imc[1024], bw_resc[1024];
 106         int runs;
 107         FILE *fp;
 108
 109         fp = fopen(output, "r");
 110         if (!fp) {
 111                 perror(output);
 112
 113                 return errno;
 114         }
 115
 116         runs = 0;
 117         while (fgets(temp, sizeof(temp), fp)) {
 118                 char *token = strtok(temp, ":\t");
 119                 int fields = 0;
 120
 121                 while (token) {
 122                         token_array[fields++] = token;
 123                         token = strtok(NULL, ":\t");
 124                 }
 125
 126                 /* Field 3 is perf imc value */
 127                 bw_imc[runs] = strtoul(token_array[3], NULL, 0);
 128                 /* Field 5 is resctrl value */
 129                 bw_resc[runs] = strtoul(token_array[5], NULL, 0);
 130                 runs++;
 131         }
 132
 133         fclose(fp);
 134
 135         show_mba_info(bw_imc, bw_resc);
 136
 137         return 0;
 138 }
 139
 140 void mba_test_cleanup(void)
 141 {
 142         remove(RESULT_FILE_NAME);
 143 }
 144
 145 int mba_schemata_change(int cpu_no, char *bw_report, char **benchmark_cmd)
 146 {
 147         struct resctrl_val_param param = {
 148                 .resctrl_val    = MBA_STR,
 149                 .ctrlgrp        = "c1",
 150                 .mongrp         = "m1",
 151                 .cpu_no         = cpu_no,
 152                 .mum_resctrlfs  = 1,
 153                 .filename       = RESULT_FILE_NAME,
 154                 .bw_report      = bw_report,
 155                 .setup          = mba_setup
 156         };
 157         int ret;
 158
 159         remove(RESULT_FILE_NAME);
 160
 161         ret = resctrl_val(benchmark_cmd, &param);
 162         if (ret)
 163                 return ret;
 164
 165         ret = check_results();
 166         if (ret)
 167                 return ret;
 168
 169         mba_test_cleanup();
 170
 171         return 0;
 172 }