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
show_bw_info(unsigned long * bw_imc,unsigned long * bw_resc,size_t span)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 if (span)
44 ksft_print_msg("Span (MB): %zu\n", span / MB);
45 ksft_print_msg("avg_bw_imc: %lu\n", avg_bw_imc);
46 ksft_print_msg("avg_bw_resc: %lu\n", avg_bw_resc);
47
48 return ret;
49 }
50
check_results(size_t span)51 static int check_results(size_t span)
52 {
53 unsigned long bw_imc[NUM_OF_RUNS], bw_resc[NUM_OF_RUNS];
54 char temp[1024], *token_array[8];
55 char output[] = RESULT_FILE_NAME;
56 int runs, ret;
57 FILE *fp;
58
59 ksft_print_msg("Checking for pass/fail\n");
60
61 fp = fopen(output, "r");
62 if (!fp) {
63 ksft_perror(output);
64
65 return -1;
66 }
67
68 runs = 0;
69 while (fgets(temp, sizeof(temp), fp)) {
70 char *token = strtok(temp, ":\t");
71 int i = 0;
72
73 while (token) {
74 token_array[i++] = token;
75 token = strtok(NULL, ":\t");
76 }
77
78 bw_resc[runs] = strtoul(token_array[5], NULL, 0);
79 bw_imc[runs] = strtoul(token_array[3], NULL, 0);
80 runs++;
81 }
82
83 ret = show_bw_info(bw_imc, bw_resc, span);
84
85 fclose(fp);
86
87 return ret;
88 }
89
mbm_init(const struct resctrl_val_param * param,int domain_id)90 static int mbm_init(const struct resctrl_val_param *param, int domain_id)
91 {
92 int ret;
93
94 ret = initialize_mem_bw_imc();
95 if (ret)
96 return ret;
97
98 initialize_mem_bw_resctrl(param, domain_id);
99
100 return 0;
101 }
102
mbm_setup(const struct resctrl_test * test,const struct user_params * uparams,struct resctrl_val_param * p)103 static int mbm_setup(const struct resctrl_test *test,
104 const struct user_params *uparams,
105 struct resctrl_val_param *p)
106 {
107 int ret = 0;
108
109 /* Run NUM_OF_RUNS times */
110 if (p->num_of_runs >= NUM_OF_RUNS)
111 return END_OF_TESTS;
112
113 /* Set up shemata with 100% allocation on the first run. */
114 if (p->num_of_runs == 0 && resctrl_resource_exists("MB"))
115 ret = write_schemata(p->ctrlgrp, "100", uparams->cpu, test->resource);
116
117 p->num_of_runs++;
118
119 return ret;
120 }
121
mbm_measure(const struct user_params * uparams,struct resctrl_val_param * param,pid_t bm_pid)122 static int mbm_measure(const struct user_params *uparams,
123 struct resctrl_val_param *param, pid_t bm_pid)
124 {
125 return measure_mem_bw(uparams, param, bm_pid, "reads");
126 }
127
mbm_test_cleanup(void)128 static void mbm_test_cleanup(void)
129 {
130 remove(RESULT_FILE_NAME);
131 }
132
mbm_run_test(const struct resctrl_test * test,const struct user_params * uparams)133 static int mbm_run_test(const struct resctrl_test *test, const struct user_params *uparams)
134 {
135 struct resctrl_val_param param = {
136 .ctrlgrp = "c1",
137 .filename = RESULT_FILE_NAME,
138 .init = mbm_init,
139 .setup = mbm_setup,
140 .measure = mbm_measure,
141 };
142 char *endptr = NULL;
143 size_t span = 0;
144 int ret;
145
146 remove(RESULT_FILE_NAME);
147
148 if (uparams->benchmark_cmd[0] && strcmp(uparams->benchmark_cmd[0], "fill_buf") == 0) {
149 if (uparams->benchmark_cmd[1] && *uparams->benchmark_cmd[1] != '\0') {
150 errno = 0;
151 span = strtoul(uparams->benchmark_cmd[1], &endptr, 10);
152 if (errno || *endptr != '\0')
153 return -EINVAL;
154 }
155 }
156
157 ret = resctrl_val(test, uparams, uparams->benchmark_cmd, ¶m);
158 if (ret)
159 return ret;
160
161 ret = check_results(span);
162 if (ret && (get_vendor() == ARCH_INTEL))
163 ksft_print_msg("Intel MBM may be inaccurate when Sub-NUMA Clustering is enabled. Check BIOS configuration.\n");
164
165 return ret;
166 }
167
mbm_feature_check(const struct resctrl_test * test)168 static bool mbm_feature_check(const struct resctrl_test *test)
169 {
170 return resctrl_mon_feature_exists("L3_MON", "mbm_total_bytes") &&
171 resctrl_mon_feature_exists("L3_MON", "mbm_local_bytes");
172 }
173
174 struct resctrl_test mbm_test = {
175 .name = "MBM",
176 .resource = "MB",
177 .vendor_specific = ARCH_INTEL,
178 .feature_check = mbm_feature_check,
179 .run_test = mbm_run_test,
180 .cleanup = mbm_test_cleanup,
181 };
182