tools/testing/selftests/resctrl/cmt_test.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Cache Monitoring Technology (CMT) 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 #include <unistd.h>
  13
  14 #define RESULT_FILE_NAME        "result_cmt"
  15 #define NUM_OF_RUNS             5
  16 #define MAX_DIFF                2000000
  17 #define MAX_DIFF_PERCENT        15
  18
  19 #define CON_MON_LCC_OCCUP_PATH          \
  20         "%s/%s/mon_data/mon_L3_%02d/llc_occupancy"
  21
  22 static int cmt_init(const struct resctrl_val_param *param, int domain_id)
  23 {
  24         sprintf(llc_occup_path, CON_MON_LCC_OCCUP_PATH, RESCTRL_PATH,
  25                 param->ctrlgrp, domain_id);
  26
  27         return 0;
  28 }
  29
  30 static int cmt_setup(const struct resctrl_test *test,
  31                      const struct user_params *uparams,
  32                      struct resctrl_val_param *p)
  33 {
  34         /* Run NUM_OF_RUNS times */
  35         if (p->num_of_runs >= NUM_OF_RUNS)
  36                 return END_OF_TESTS;
  37
  38         p->num_of_runs++;
  39
  40         return 0;
  41 }
  42
  43 static int cmt_measure(const struct user_params *uparams,
  44                        struct resctrl_val_param *param, pid_t bm_pid)
  45 {
  46         sleep(1);
  47         return measure_llc_resctrl(param->filename, bm_pid);
  48 }
  49
  50 static int show_results_info(unsigned long sum_llc_val, int no_of_bits,
  51                              unsigned long cache_span, unsigned long max_diff,
  52                              unsigned long max_diff_percent, unsigned long num_of_runs,
  53                              bool platform)
  54 {
  55         unsigned long avg_llc_val = 0;
  56         float diff_percent;
  57         long avg_diff = 0;
  58         int ret;
  59
  60         avg_llc_val = sum_llc_val / num_of_runs;
  61         avg_diff = (long)(cache_span - avg_llc_val);
  62         diff_percent = ((float)cache_span - avg_llc_val) / cache_span * 100;
  63
  64         ret = platform && abs((int)diff_percent) > max_diff_percent &&
  65               labs(avg_diff) > max_diff;
  66
  67         ksft_print_msg("%s Check cache miss rate within %lu%%\n",
  68                        ret ? "Fail:" : "Pass:", max_diff_percent);
  69
  70         ksft_print_msg("Percent diff=%d\n", abs((int)diff_percent));
  71
  72         show_cache_info(no_of_bits, avg_llc_val, cache_span, false);
  73
  74         return ret;
  75 }
  76
  77 static int check_results(struct resctrl_val_param *param, size_t span, int no_of_bits)
  78 {
  79         char *token_array[8], temp[512];
  80         unsigned long sum_llc_occu_resc = 0;
  81         int runs = 0;
  82         FILE *fp;
  83
  84         ksft_print_msg("Checking for pass/fail\n");
  85         fp = fopen(param->filename, "r");
  86         if (!fp) {
  87                 ksft_perror("Error in opening file");
  88
  89                 return -1;
  90         }
  91
  92         while (fgets(temp, sizeof(temp), fp)) {
  93                 char *token = strtok(temp, ":\t");
  94                 int fields = 0;
  95
  96                 while (token) {
  97                         token_array[fields++] = token;
  98                         token = strtok(NULL, ":\t");
  99                 }
 100
 101                 /* Field 3 is llc occ resc value */
 102                 sum_llc_occu_resc += strtoul(token_array[3], NULL, 0);
 103                 runs++;
 104         }
 105         fclose(fp);
 106
 107         return show_results_info(sum_llc_occu_resc, no_of_bits, span,
 108                                  MAX_DIFF, MAX_DIFF_PERCENT, runs, true);
 109 }
 110
 111 static void cmt_test_cleanup(void)
 112 {
 113         remove(RESULT_FILE_NAME);
 114 }
 115
 116 static int cmt_run_test(const struct resctrl_test *test, const struct user_params *uparams)
 117 {
 118         struct fill_buf_param fill_buf = {};
 119         unsigned long cache_total_size = 0;
 120         int n = uparams->bits ? : 5;
 121         unsigned long long_mask;
 122         int count_of_bits;
 123         size_t span;
 124         int ret;
 125
 126         ret = get_full_cbm("L3", &long_mask);
 127         if (ret)
 128                 return ret;
 129
 130         ret = get_cache_size(uparams->cpu, "L3", &cache_total_size);
 131         if (ret)
 132                 return ret;
 133         ksft_print_msg("Cache size :%lu\n", cache_total_size);
 134
 135         count_of_bits = count_bits(long_mask);
 136
 137         if (n < 1 || n > count_of_bits) {
 138                 ksft_print_msg("Invalid input value for numbr_of_bits n!\n");
 139                 ksft_print_msg("Please enter value in range 1 to %d\n", count_of_bits);
 140                 return -1;
 141         }
 142
 143         struct resctrl_val_param param = {
 144                 .ctrlgrp        = "c1",
 145                 .filename       = RESULT_FILE_NAME,
 146                 .mask           = ~(long_mask << n) & long_mask,
 147                 .num_of_runs    = 0,
 148                 .init           = cmt_init,
 149                 .setup          = cmt_setup,
 150                 .measure        = cmt_measure,
 151         };
 152
 153         span = cache_portion_size(cache_total_size, param.mask, long_mask);
 154
 155         if (uparams->fill_buf) {
 156                 fill_buf.buf_size = span;
 157                 fill_buf.memflush = uparams->fill_buf->memflush;
 158                 param.fill_buf = &fill_buf;
 159         } else if (!uparams->benchmark_cmd[0]) {
 160                 fill_buf.buf_size = span;
 161                 fill_buf.memflush = true;
 162                 param.fill_buf = &fill_buf;
 163         }
 164
 165         remove(RESULT_FILE_NAME);
 166
 167         ret = resctrl_val(test, uparams, &param);
 168         if (ret)
 169                 return ret;
 170
 171         ret = check_results(&param, span, n);
 172         if (ret && (get_vendor() == ARCH_INTEL))
 173                 ksft_print_msg("Intel CMT may be inaccurate when Sub-NUMA Clustering is enabled. Check BIOS configuration.\n");
 174
 175         return ret;
 176 }
 177
 178 static bool cmt_feature_check(const struct resctrl_test *test)
 179 {
 180         return test_resource_feature_check(test) &&
 181                resctrl_mon_feature_exists("L3_MON", "llc_occupancy");
 182 }
 183
 184 struct resctrl_test cmt_test = {
 185         .name = "CMT",
 186         .resource = "L3",
 187         .feature_check = cmt_feature_check,
 188         .run_test = cmt_run_test,
 189         .cleanup = cmt_test_cleanup,
 190 };