xref: /linux/tools/testing/selftests/resctrl/mba_test.c (revision 001821b0e79716c4e17c71d8e053a23599a7a508)
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 /*
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  */
25 static int mba_setup(const struct resctrl_test *test,
26 		     const struct user_params *uparams,
27 		     struct resctrl_val_param *p)
28 {
29 	static int runs_per_allocation, allocation = 100;
30 	char allocation_str[64];
31 	int ret;
32 
33 	if (runs_per_allocation >= NUM_OF_RUNS)
34 		runs_per_allocation = 0;
35 
36 	/* Only set up schemata once every NUM_OF_RUNS of allocations */
37 	if (runs_per_allocation++ != 0)
38 		return 0;
39 
40 	if (allocation < ALLOCATION_MIN || allocation > ALLOCATION_MAX)
41 		return END_OF_TESTS;
42 
43 	sprintf(allocation_str, "%d", allocation);
44 
45 	ret = write_schemata(p->ctrlgrp, allocation_str, uparams->cpu, test->resource);
46 	if (ret < 0)
47 		return ret;
48 
49 	allocation -= ALLOCATION_STEP;
50 
51 	return 0;
52 }
53 
54 static bool show_mba_info(unsigned long *bw_imc, unsigned long *bw_resc)
55 {
56 	int allocation, runs;
57 	bool ret = false;
58 
59 	ksft_print_msg("Results are displayed in (MB)\n");
60 	/* Memory bandwidth from 100% down to 10% */
61 	for (allocation = 0; allocation < ALLOCATION_MAX / ALLOCATION_STEP;
62 	     allocation++) {
63 		unsigned long sum_bw_imc = 0, sum_bw_resc = 0;
64 		long avg_bw_imc, avg_bw_resc;
65 		int avg_diff_per;
66 		float avg_diff;
67 
68 		/*
69 		 * The first run is discarded due to inaccurate value from
70 		 * phase transition.
71 		 */
72 		for (runs = NUM_OF_RUNS * allocation + 1;
73 		     runs < NUM_OF_RUNS * allocation + NUM_OF_RUNS ; runs++) {
74 			sum_bw_imc += bw_imc[runs];
75 			sum_bw_resc += bw_resc[runs];
76 		}
77 
78 		avg_bw_imc = sum_bw_imc / (NUM_OF_RUNS - 1);
79 		avg_bw_resc = sum_bw_resc / (NUM_OF_RUNS - 1);
80 		avg_diff = (float)labs(avg_bw_resc - avg_bw_imc) / avg_bw_imc;
81 		avg_diff_per = (int)(avg_diff * 100);
82 
83 		ksft_print_msg("%s Check MBA diff within %d%% for schemata %u\n",
84 			       avg_diff_per > MAX_DIFF_PERCENT ?
85 			       "Fail:" : "Pass:",
86 			       MAX_DIFF_PERCENT,
87 			       ALLOCATION_MAX - ALLOCATION_STEP * allocation);
88 
89 		ksft_print_msg("avg_diff_per: %d%%\n", avg_diff_per);
90 		ksft_print_msg("avg_bw_imc: %lu\n", avg_bw_imc);
91 		ksft_print_msg("avg_bw_resc: %lu\n", avg_bw_resc);
92 		if (avg_diff_per > MAX_DIFF_PERCENT)
93 			ret = true;
94 	}
95 
96 	ksft_print_msg("%s Check schemata change using MBA\n",
97 		       ret ? "Fail:" : "Pass:");
98 	if (ret)
99 		ksft_print_msg("At least one test failed\n");
100 
101 	return ret;
102 }
103 
104 static int check_results(void)
105 {
106 	char *token_array[8], output[] = RESULT_FILE_NAME, temp[512];
107 	unsigned long bw_imc[1024], bw_resc[1024];
108 	int runs;
109 	FILE *fp;
110 
111 	fp = fopen(output, "r");
112 	if (!fp) {
113 		ksft_perror(output);
114 
115 		return -1;
116 	}
117 
118 	runs = 0;
119 	while (fgets(temp, sizeof(temp), fp)) {
120 		char *token = strtok(temp, ":\t");
121 		int fields = 0;
122 
123 		while (token) {
124 			token_array[fields++] = token;
125 			token = strtok(NULL, ":\t");
126 		}
127 
128 		/* Field 3 is perf imc value */
129 		bw_imc[runs] = strtoul(token_array[3], NULL, 0);
130 		/* Field 5 is resctrl value */
131 		bw_resc[runs] = strtoul(token_array[5], NULL, 0);
132 		runs++;
133 	}
134 
135 	fclose(fp);
136 
137 	return show_mba_info(bw_imc, bw_resc);
138 }
139 
140 static void mba_test_cleanup(void)
141 {
142 	remove(RESULT_FILE_NAME);
143 }
144 
145 static int mba_run_test(const struct resctrl_test *test, const struct user_params *uparams)
146 {
147 	struct resctrl_val_param param = {
148 		.resctrl_val	= MBA_STR,
149 		.ctrlgrp	= "c1",
150 		.mongrp		= "m1",
151 		.filename	= RESULT_FILE_NAME,
152 		.bw_report	= "reads",
153 		.setup		= mba_setup
154 	};
155 	int ret;
156 
157 	remove(RESULT_FILE_NAME);
158 
159 	ret = resctrl_val(test, uparams, uparams->benchmark_cmd, &param);
160 	if (ret)
161 		return ret;
162 
163 	ret = check_results();
164 
165 	return ret;
166 }
167 
168 static bool mba_feature_check(const struct resctrl_test *test)
169 {
170 	return test_resource_feature_check(test) &&
171 	       resctrl_mon_feature_exists("L3_MON", "mbm_local_bytes");
172 }
173 
174 struct resctrl_test mba_test = {
175 	.name = "MBA",
176 	.resource = "MB",
177 	.vendor_specific = ARCH_INTEL,
178 	.feature_check = mba_feature_check,
179 	.run_test = mba_run_test,
180 	.cleanup = mba_test_cleanup,
181 };
182