1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Memory Bandwidth Allocation (MBA) 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_mba"
14 #define NUM_OF_RUNS 5
15 #define MAX_DIFF_PERCENT 8
16 #define ALLOCATION_MAX 100
17 #define ALLOCATION_MIN 10
18 #define ALLOCATION_STEP 10
19
20 static int mba_init(const struct resctrl_val_param *param, int domain_id)
21 {
22 int ret;
23
24 ret = initialize_mem_bw_imc();
25 if (ret)
26 return ret;
27
28 initialize_mem_bw_resctrl(param, domain_id);
29
30 return 0;
31 }
32
33 /*
34 * Change schemata percentage from 100 to 10%. Write schemata to specified
35 * con_mon grp, mon_grp in resctrl FS.
36 * For each allocation, run 5 times in order to get average values.
37 */
38 static int mba_setup(const struct resctrl_test *test,
39 const struct user_params *uparams,
40 struct resctrl_val_param *p)
41 {
42 static int runs_per_allocation, allocation = 100;
43 char allocation_str[64];
44 int ret;
45
46 if (runs_per_allocation >= NUM_OF_RUNS)
47 runs_per_allocation = 0;
48
49 /* Only set up schemata once every NUM_OF_RUNS of allocations */
50 if (runs_per_allocation++ != 0)
51 return 0;
52
53 if (allocation < ALLOCATION_MIN || allocation > ALLOCATION_MAX)
54 return END_OF_TESTS;
55
56 sprintf(allocation_str, "%d", allocation);
57
58 ret = write_schemata(p->ctrlgrp, allocation_str, uparams->cpu, test->resource);
59 if (ret < 0)
60 return ret;
61
62 allocation -= ALLOCATION_STEP;
63
64 return 0;
65 }
66
67 static int mba_measure(const struct user_params *uparams,
68 struct resctrl_val_param *param, pid_t bm_pid)
69 {
70 return measure_mem_bw(uparams, param, bm_pid, "reads");
71 }
72
73 static bool show_mba_info(unsigned long *bw_imc, unsigned long *bw_resc)
74 {
75 int allocation, runs;
76 bool ret = false;
77
78 ksft_print_msg("Results are displayed in (MB)\n");
79 /* Memory bandwidth from 100% down to 10% */
80 for (allocation = 0; allocation < ALLOCATION_MAX / ALLOCATION_STEP;
81 allocation++) {
82 unsigned long sum_bw_imc = 0, sum_bw_resc = 0;
83 long avg_bw_imc, avg_bw_resc;
84 int avg_diff_per;
85 float avg_diff;
86
87 /*
88 * The first run is discarded due to inaccurate value from
89 * phase transition.
90 */
91 for (runs = NUM_OF_RUNS * allocation + 1;
92 runs < NUM_OF_RUNS * allocation + NUM_OF_RUNS ; runs++) {
93 sum_bw_imc += bw_imc[runs];
94 sum_bw_resc += bw_resc[runs];
95 }
96
97 avg_bw_imc = sum_bw_imc / (NUM_OF_RUNS - 1);
98 avg_bw_resc = sum_bw_resc / (NUM_OF_RUNS - 1);
99 avg_diff = (float)labs(avg_bw_resc - avg_bw_imc) / avg_bw_imc;
100 avg_diff_per = (int)(avg_diff * 100);
101
102 ksft_print_msg("%s Check MBA diff within %d%% for schemata %u\n",
103 avg_diff_per > MAX_DIFF_PERCENT ?
104 "Fail:" : "Pass:",
105 MAX_DIFF_PERCENT,
106 ALLOCATION_MAX - ALLOCATION_STEP * allocation);
107
108 ksft_print_msg("avg_diff_per: %d%%\n", avg_diff_per);
109 ksft_print_msg("avg_bw_imc: %lu\n", avg_bw_imc);
110 ksft_print_msg("avg_bw_resc: %lu\n", avg_bw_resc);
111 if (avg_diff_per > MAX_DIFF_PERCENT)
112 ret = true;
113 }
114
115 ksft_print_msg("%s Check schemata change using MBA\n",
116 ret ? "Fail:" : "Pass:");
117 if (ret)
118 ksft_print_msg("At least one test failed\n");
119
120 return ret;
121 }
122
123 static int check_results(void)
124 {
125 char *token_array[8], output[] = RESULT_FILE_NAME, temp[512];
126 unsigned long bw_imc[1024], bw_resc[1024];
127 int runs;
128 FILE *fp;
129
130 fp = fopen(output, "r");
131 if (!fp) {
132 ksft_perror(output);
133
134 return -1;
135 }
136
137 runs = 0;
138 while (fgets(temp, sizeof(temp), fp)) {
139 char *token = strtok(temp, ":\t");
140 int fields = 0;
141
142 while (token) {
143 token_array[fields++] = token;
144 token = strtok(NULL, ":\t");
145 }
146
147 /* Field 3 is perf imc value */
148 bw_imc[runs] = strtoul(token_array[3], NULL, 0);
149 /* Field 5 is resctrl value */
150 bw_resc[runs] = strtoul(token_array[5], NULL, 0);
151 runs++;
152 }
153
154 fclose(fp);
155
156 return show_mba_info(bw_imc, bw_resc);
157 }
158
159 static void mba_test_cleanup(void)
160 {
161 remove(RESULT_FILE_NAME);
162 }
163
164 static int mba_run_test(const struct resctrl_test *test, const struct user_params *uparams)
165 {
166 struct resctrl_val_param param = {
167 .ctrlgrp = "c1",
168 .filename = RESULT_FILE_NAME,
169 .init = mba_init,
170 .setup = mba_setup,
171 .measure = mba_measure,
172 };
173 int ret;
174
175 remove(RESULT_FILE_NAME);
176
177 ret = resctrl_val(test, uparams, uparams->benchmark_cmd, ¶m);
178 if (ret)
179 return ret;
180
181 ret = check_results();
182
183 return ret;
184 }
185
186 static bool mba_feature_check(const struct resctrl_test *test)
187 {
188 return test_resource_feature_check(test) &&
189 resctrl_mon_feature_exists("L3_MON", "mbm_local_bytes");
190 }
191
192 struct resctrl_test mba_test = {
193 .name = "MBA",
194 .resource = "MB",
195 .vendor_specific = ARCH_INTEL,
196 .feature_check = mba_feature_check,
197 .run_test = mba_run_test,
198 .cleanup = mba_test_cleanup,
199 };
200
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