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_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 static 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, ¶m); 128 if (ret) 129 return ret; 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 return ret; 136 } 137 138 static bool mbm_feature_check(const struct resctrl_test *test) 139 { 140 return resctrl_mon_feature_exists("L3_MON", "mbm_total_bytes") && 141 resctrl_mon_feature_exists("L3_MON", "mbm_local_bytes"); 142 } 143 144 struct resctrl_test mbm_test = { 145 .name = "MBM", 146 .resource = "MB", 147 .vendor_specific = ARCH_INTEL, 148 .feature_check = mbm_feature_check, 149 .run_test = mbm_run_test, 150 .cleanup = mbm_test_cleanup, 151 }; 152