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 avg_bw_imc = 0, avg_bw_resc = 0;
21 unsigned long sum_bw_imc = 0, sum_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
check_results(size_t span)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 perror(output);
63
64 return errno;
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
mbm_setup(struct resctrl_val_param * p)89 static int mbm_setup(struct resctrl_val_param *p)
90 {
91 int ret = 0;
92
93 /* Run NUM_OF_RUNS times */
94 if (p->num_of_runs >= NUM_OF_RUNS)
95 return END_OF_TESTS;
96
97 /* Set up shemata with 100% allocation on the first run. */
98 if (p->num_of_runs == 0)
99 ret = write_schemata(p->ctrlgrp, "100", p->cpu_no,
100 p->resctrl_val);
101
102 p->num_of_runs++;
103
104 return ret;
105 }
106
mbm_test_cleanup(void)107 void mbm_test_cleanup(void)
108 {
109 remove(RESULT_FILE_NAME);
110 }
111
mbm_bw_change(int cpu_no,const char * const * benchmark_cmd)112 int mbm_bw_change(int cpu_no, const char * const *benchmark_cmd)
113 {
114 struct resctrl_val_param param = {
115 .resctrl_val = MBM_STR,
116 .ctrlgrp = "c1",
117 .mongrp = "m1",
118 .cpu_no = cpu_no,
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(benchmark_cmd, ¶m);
128 if (ret)
129 goto out;
130
131 ret = check_results(DEFAULT_SPAN);
132
133 out:
134 mbm_test_cleanup();
135
136 return ret;
137 }
138