Linux kernel mirror (for testing)
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linux
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 5
16#define ALLOCATION_MAX 100
17#define ALLOCATION_MIN 10
18#define ALLOCATION_STEP 10
19
20/*
21 * Change schemata percentage from 100 to 10%. Write schemata to specified
22 * con_mon grp, mon_grp in resctrl FS.
23 * For each allocation, run 5 times in order to get average values.
24 */
25static int mba_setup(int num, ...)
26{
27 static int runs_per_allocation, allocation = 100;
28 struct resctrl_val_param *p;
29 char allocation_str[64];
30 va_list param;
31 int ret;
32
33 va_start(param, num);
34 p = va_arg(param, struct resctrl_val_param *);
35 va_end(param);
36
37 if (runs_per_allocation >= NUM_OF_RUNS)
38 runs_per_allocation = 0;
39
40 /* Only set up schemata once every NUM_OF_RUNS of allocations */
41 if (runs_per_allocation++ != 0)
42 return 0;
43
44 if (allocation < ALLOCATION_MIN || allocation > ALLOCATION_MAX)
45 return END_OF_TESTS;
46
47 sprintf(allocation_str, "%d", allocation);
48
49 ret = write_schemata(p->ctrlgrp, allocation_str, p->cpu_no,
50 p->resctrl_val);
51 if (ret < 0)
52 return ret;
53
54 allocation -= ALLOCATION_STEP;
55
56 return 0;
57}
58
59static bool show_mba_info(unsigned long *bw_imc, unsigned long *bw_resc)
60{
61 int allocation, runs;
62 bool ret = false;
63
64 ksft_print_msg("Results are displayed in (MB)\n");
65 /* Memory bandwidth from 100% down to 10% */
66 for (allocation = 0; allocation < ALLOCATION_MAX / ALLOCATION_STEP;
67 allocation++) {
68 unsigned long avg_bw_imc, avg_bw_resc;
69 unsigned long sum_bw_imc = 0, sum_bw_resc = 0;
70 int avg_diff_per;
71 float avg_diff;
72
73 /*
74 * The first run is discarded due to inaccurate value from
75 * phase transition.
76 */
77 for (runs = NUM_OF_RUNS * allocation + 1;
78 runs < NUM_OF_RUNS * allocation + NUM_OF_RUNS ; runs++) {
79 sum_bw_imc += bw_imc[runs];
80 sum_bw_resc += bw_resc[runs];
81 }
82
83 avg_bw_imc = sum_bw_imc / (NUM_OF_RUNS - 1);
84 avg_bw_resc = sum_bw_resc / (NUM_OF_RUNS - 1);
85 avg_diff = (float)labs(avg_bw_resc - avg_bw_imc) / avg_bw_imc;
86 avg_diff_per = (int)(avg_diff * 100);
87
88 ksft_print_msg("%s Check MBA diff within %d%% for schemata %u\n",
89 avg_diff_per > MAX_DIFF_PERCENT ?
90 "Fail:" : "Pass:",
91 MAX_DIFF_PERCENT,
92 ALLOCATION_MAX - ALLOCATION_STEP * allocation);
93
94 ksft_print_msg("avg_diff_per: %d%%\n", avg_diff_per);
95 ksft_print_msg("avg_bw_imc: %lu\n", avg_bw_imc);
96 ksft_print_msg("avg_bw_resc: %lu\n", avg_bw_resc);
97 if (avg_diff_per > MAX_DIFF_PERCENT)
98 ret = true;
99 }
100
101 ksft_print_msg("%s Check schemata change using MBA\n",
102 ret ? "Fail:" : "Pass:");
103 if (ret)
104 ksft_print_msg("At least one test failed\n");
105
106 return ret;
107}
108
109static int check_results(void)
110{
111 char *token_array[8], output[] = RESULT_FILE_NAME, temp[512];
112 unsigned long bw_imc[1024], bw_resc[1024];
113 int runs;
114 FILE *fp;
115
116 fp = fopen(output, "r");
117 if (!fp) {
118 perror(output);
119
120 return errno;
121 }
122
123 runs = 0;
124 while (fgets(temp, sizeof(temp), fp)) {
125 char *token = strtok(temp, ":\t");
126 int fields = 0;
127
128 while (token) {
129 token_array[fields++] = token;
130 token = strtok(NULL, ":\t");
131 }
132
133 /* Field 3 is perf imc value */
134 bw_imc[runs] = strtoul(token_array[3], NULL, 0);
135 /* Field 5 is resctrl value */
136 bw_resc[runs] = strtoul(token_array[5], NULL, 0);
137 runs++;
138 }
139
140 fclose(fp);
141
142 return show_mba_info(bw_imc, bw_resc);
143}
144
145void mba_test_cleanup(void)
146{
147 remove(RESULT_FILE_NAME);
148}
149
150int mba_schemata_change(int cpu_no, char *bw_report, char **benchmark_cmd)
151{
152 struct resctrl_val_param param = {
153 .resctrl_val = MBA_STR,
154 .ctrlgrp = "c1",
155 .mongrp = "m1",
156 .cpu_no = cpu_no,
157 .mum_resctrlfs = true,
158 .filename = RESULT_FILE_NAME,
159 .bw_report = bw_report,
160 .setup = mba_setup
161 };
162 int ret;
163
164 remove(RESULT_FILE_NAME);
165
166 ret = resctrl_val(benchmark_cmd, ¶m);
167 if (ret)
168 goto out;
169
170 ret = check_results();
171
172out:
173 mba_test_cleanup();
174
175 return ret;
176}