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 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 /* 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_init(const struct resctrl_val_param *param, int domain_id) 90 { 91 int ret; 92 93 ret = initialize_mem_bw_imc(); 94 if (ret) 95 return ret; 96 97 initialize_mem_bw_resctrl(param, domain_id); 98 99 return 0; 100 } 101 102 static int mbm_setup(const struct resctrl_test *test, 103 const struct user_params *uparams, 104 struct resctrl_val_param *p) 105 { 106 int ret = 0; 107 108 /* Run NUM_OF_RUNS times */ 109 if (p->num_of_runs >= NUM_OF_RUNS) 110 return END_OF_TESTS; 111 112 /* Set up shemata with 100% allocation on the first run. */ 113 if (p->num_of_runs == 0 && resctrl_resource_exists("MB")) 114 ret = write_schemata(p->ctrlgrp, "100", uparams->cpu, test->resource); 115 116 p->num_of_runs++; 117 118 return ret; 119 } 120 121 static int mbm_measure(const struct user_params *uparams, 122 struct resctrl_val_param *param, pid_t bm_pid) 123 { 124 return measure_mem_bw(uparams, param, bm_pid, "reads"); 125 } 126 127 static void mbm_test_cleanup(void) 128 { 129 remove(RESULT_FILE_NAME); 130 } 131 132 static int mbm_run_test(const struct resctrl_test *test, const struct user_params *uparams) 133 { 134 struct resctrl_val_param param = { 135 .ctrlgrp = "c1", 136 .filename = RESULT_FILE_NAME, 137 .init = mbm_init, 138 .setup = mbm_setup, 139 .measure = mbm_measure, 140 }; 141 int ret; 142 143 remove(RESULT_FILE_NAME); 144 145 ret = resctrl_val(test, uparams, uparams->benchmark_cmd, ¶m); 146 if (ret) 147 return ret; 148 149 ret = check_results(DEFAULT_SPAN); 150 if (ret && (get_vendor() == ARCH_INTEL)) 151 ksft_print_msg("Intel MBM may be inaccurate when Sub-NUMA Clustering is enabled. Check BIOS configuration.\n"); 152 153 return ret; 154 } 155 156 static bool mbm_feature_check(const struct resctrl_test *test) 157 { 158 return resctrl_mon_feature_exists("L3_MON", "mbm_total_bytes") && 159 resctrl_mon_feature_exists("L3_MON", "mbm_local_bytes"); 160 } 161 162 struct resctrl_test mbm_test = { 163 .name = "MBM", 164 .resource = "MB", 165 .vendor_specific = ARCH_INTEL, 166 .feature_check = mbm_feature_check, 167 .run_test = mbm_run_test, 168 .cleanup = mbm_test_cleanup, 169 }; 170