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        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 sum_bw_imc = 0, sum_bw_resc = 0;
  21         long avg_bw_imc = 0, avg_bw_resc = 0;
  22         int runs, ret, avg_diff_per;
  23         float avg_diff = 0;
  24
  25         for (runs = 0; runs < NUM_OF_RUNS; runs++) {
  26                 sum_bw_imc += bw_imc[runs];
  27                 sum_bw_resc += bw_resc[runs];
  28         }
  29
  30         avg_bw_imc = sum_bw_imc / NUM_OF_RUNS;
  31         avg_bw_resc = sum_bw_resc / NUM_OF_RUNS;
  32         avg_diff = (float)labs(avg_bw_resc - avg_bw_imc) / avg_bw_imc;
  33         avg_diff_per = (int)(avg_diff * 100);
  34
  35         ret = avg_diff_per > MAX_DIFF_PERCENT;
  36         ksft_print_msg("%s Check MBM diff within %d%%\n",
  37                        ret ? "Fail:" : "Pass:", MAX_DIFF_PERCENT);
  38         ksft_print_msg("avg_diff_per: %d%%\n", avg_diff_per);
  39         if (span)
  40                 ksft_print_msg("Span (MB): %zu\n", span / MB);
  41         ksft_print_msg("avg_bw_imc: %lu\n", avg_bw_imc);
  42         ksft_print_msg("avg_bw_resc: %lu\n", avg_bw_resc);
  43
  44         return ret;
  45 }
  46
  47 static int check_results(size_t span)
  48 {
  49         unsigned long bw_imc[NUM_OF_RUNS], bw_resc[NUM_OF_RUNS];
  50         char temp[1024], *token_array[8];
  51         char output[] = RESULT_FILE_NAME;
  52         int runs, ret;
  53         FILE *fp;
  54
  55         ksft_print_msg("Checking for pass/fail\n");
  56
  57         fp = fopen(output, "r");
  58         if (!fp) {
  59                 ksft_perror(output);
  60
  61                 return -1;
  62         }
  63
  64         runs = 0;
  65         while (fgets(temp, sizeof(temp), fp)) {
  66                 char *token = strtok(temp, ":\t");
  67                 int i = 0;
  68
  69                 while (token) {
  70                         token_array[i++] = token;
  71                         token = strtok(NULL, ":\t");
  72                 }
  73
  74                 bw_resc[runs] = strtoul(token_array[5], NULL, 0);
  75                 bw_imc[runs] = strtoul(token_array[3], NULL, 0);
  76                 runs++;
  77         }
  78
  79         ret = show_bw_info(bw_imc, bw_resc, span);
  80
  81         fclose(fp);
  82
  83         return ret;
  84 }
  85
  86 static int mbm_init(const struct resctrl_val_param *param, int domain_id)
  87 {
  88         int ret;
  89
  90         ret = initialize_read_mem_bw_imc();
  91         if (ret)
  92                 return ret;
  93
  94         initialize_mem_bw_resctrl(param, domain_id);
  95
  96         return 0;
  97 }
  98
  99 static int mbm_setup(const struct resctrl_test *test,
 100                      const struct user_params *uparams,
 101                      struct resctrl_val_param *p)
 102 {
 103         int ret = 0;
 104
 105         /* Run NUM_OF_RUNS times */
 106         if (p->num_of_runs >= NUM_OF_RUNS)
 107                 return END_OF_TESTS;
 108
 109         /* Set up shemata with 100% allocation on the first run. */
 110         if (p->num_of_runs == 0 && resctrl_resource_exists("MB"))
 111                 ret = write_schemata(p->ctrlgrp, "100", uparams->cpu, test->resource);
 112
 113         p->num_of_runs++;
 114
 115         return ret;
 116 }
 117
 118 static int mbm_measure(const struct user_params *uparams,
 119                        struct resctrl_val_param *param, pid_t bm_pid)
 120 {
 121         return measure_read_mem_bw(uparams, param, bm_pid);
 122 }
 123
 124 static void mbm_test_cleanup(void)
 125 {
 126         remove(RESULT_FILE_NAME);
 127 }
 128
 129 static int mbm_run_test(const struct resctrl_test *test, const struct user_params *uparams)
 130 {
 131         struct resctrl_val_param param = {
 132                 .ctrlgrp        = "c1",
 133                 .filename       = RESULT_FILE_NAME,
 134                 .init           = mbm_init,
 135                 .setup          = mbm_setup,
 136                 .measure        = mbm_measure,
 137         };
 138         struct fill_buf_param fill_buf = {};
 139         int ret;
 140
 141         remove(RESULT_FILE_NAME);
 142
 143         if (uparams->fill_buf) {
 144                 fill_buf.buf_size = uparams->fill_buf->buf_size;
 145                 fill_buf.memflush = uparams->fill_buf->memflush;
 146                 param.fill_buf = &fill_buf;
 147         } else if (!uparams->benchmark_cmd[0]) {
 148                 ssize_t buf_size;
 149
 150                 buf_size = get_fill_buf_size(uparams->cpu, "L3");
 151                 if (buf_size < 0)
 152                         return buf_size;
 153                 fill_buf.buf_size = buf_size;
 154                 fill_buf.memflush = true;
 155                 param.fill_buf = &fill_buf;
 156         }
 157
 158         ret = resctrl_val(test, uparams, &param);
 159         if (ret)
 160                 return ret;
 161
 162         ret = check_results(param.fill_buf ? param.fill_buf->buf_size : 0);
 163         if (ret && (get_vendor() == ARCH_INTEL))
 164                 ksft_print_msg("Intel MBM may be inaccurate when Sub-NUMA Clustering is enabled. Check BIOS configuration.\n");
 165
 166         return ret;
 167 }
 168
 169 static bool mbm_feature_check(const struct resctrl_test *test)
 170 {
 171         return resctrl_mon_feature_exists("L3_MON", "mbm_total_bytes") &&
 172                resctrl_mon_feature_exists("L3_MON", "mbm_local_bytes");
 173 }
 174
 175 struct resctrl_test mbm_test = {
 176         .name = "MBM",
 177         .resource = "MB",
 178         .vendor_specific = ARCH_INTEL,
 179         .feature_check = mbm_feature_check,
 180         .run_test = mbm_run_test,
 181         .cleanup = mbm_test_cleanup,
 182 };