xref: /linux/tools/testing/selftests/resctrl/mba_test.c (revision 056a5087d87ead77dedbe9cf5bde53b7cd4b4651)
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	15
16 #define ALLOCATION_MAX		100
17 #define ALLOCATION_MIN		10
18 #define ALLOCATION_STEP		10
19 
20 static int mba_init(const struct resctrl_test *test,
21 		    const struct user_params *uparams,
22 		    const struct resctrl_val_param *param, int domain_id)
23 {
24 	int ret;
25 
26 	ret = initialize_read_mem_bw_imc();
27 	if (ret)
28 		return ret;
29 
30 	initialize_mem_bw_resctrl(param, domain_id);
31 
32 	return 0;
33 }
34 
35 /*
36  * Change schemata percentage from 100 to 10%. Write schemata to specified
37  * con_mon grp, mon_grp in resctrl FS.
38  * For each allocation, run 5 times in order to get average values.
39  */
40 static int mba_setup(const struct resctrl_test *test,
41 		     const struct user_params *uparams,
42 		     struct resctrl_val_param *p)
43 {
44 	static unsigned int allocation = ALLOCATION_MIN;
45 	static int runs_per_allocation;
46 	char allocation_str[64];
47 	int ret;
48 
49 	if (runs_per_allocation >= NUM_OF_RUNS)
50 		runs_per_allocation = 0;
51 
52 	/* Only set up schemata once every NUM_OF_RUNS of allocations */
53 	if (runs_per_allocation++ != 0)
54 		return 0;
55 
56 	if (allocation > ALLOCATION_MAX)
57 		return END_OF_TESTS;
58 
59 	sprintf(allocation_str, "%d", allocation);
60 
61 	ret = write_schemata(p->ctrlgrp, allocation_str, uparams->cpu, test->resource);
62 	if (ret < 0)
63 		return ret;
64 
65 	allocation += ALLOCATION_STEP;
66 
67 	return 0;
68 }
69 
70 static int mba_measure(const struct user_params *uparams,
71 		       struct resctrl_val_param *param, pid_t bm_pid)
72 {
73 	return measure_read_mem_bw(uparams, param, bm_pid);
74 }
75 
76 static bool show_mba_info(unsigned long *bw_imc, unsigned long *bw_resc)
77 {
78 	unsigned int allocation;
79 	bool ret = false;
80 	int runs;
81 
82 	ksft_print_msg("Results are displayed in (MB)\n");
83 	/* Memory bandwidth from 100% down to 10% */
84 	for (allocation = 0; allocation < ALLOCATION_MAX / ALLOCATION_STEP;
85 	     allocation++) {
86 		unsigned long sum_bw_imc = 0, sum_bw_resc = 0;
87 		long avg_bw_imc, avg_bw_resc;
88 		int avg_diff_per;
89 		float avg_diff;
90 
91 		for (runs = NUM_OF_RUNS * allocation;
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;
98 		avg_bw_resc = sum_bw_resc / NUM_OF_RUNS;
99 		if (avg_bw_imc < THROTTLE_THRESHOLD || avg_bw_resc < THROTTLE_THRESHOLD) {
100 			ksft_print_msg("Bandwidth below threshold (%d MiB). Dropping results from MBA schemata %u.\n",
101 				       THROTTLE_THRESHOLD,
102 				       ALLOCATION_MIN + ALLOCATION_STEP * allocation);
103 			continue;
104 		}
105 
106 		avg_diff = (float)labs(avg_bw_resc - avg_bw_imc) / avg_bw_imc;
107 		avg_diff_per = (int)(avg_diff * 100);
108 
109 		ksft_print_msg("%s Check MBA diff within %d%% for schemata %u\n",
110 			       avg_diff_per > MAX_DIFF_PERCENT ?
111 			       "Fail:" : "Pass:",
112 			       MAX_DIFF_PERCENT,
113 			       ALLOCATION_MIN + ALLOCATION_STEP * allocation);
114 
115 		ksft_print_msg("avg_diff_per: %d%%\n", avg_diff_per);
116 		ksft_print_msg("avg_bw_imc: %lu\n", avg_bw_imc);
117 		ksft_print_msg("avg_bw_resc: %lu\n", avg_bw_resc);
118 		if (avg_diff_per > MAX_DIFF_PERCENT)
119 			ret = true;
120 	}
121 
122 	ksft_print_msg("%s Check schemata change using MBA\n",
123 		       ret ? "Fail:" : "Pass:");
124 	if (ret)
125 		ksft_print_msg("At least one test failed\n");
126 
127 	return ret;
128 }
129 
130 static int check_results(void)
131 {
132 	unsigned long bw_resc[NUM_OF_RUNS * ALLOCATION_MAX / ALLOCATION_STEP];
133 	unsigned long bw_imc[NUM_OF_RUNS * ALLOCATION_MAX / ALLOCATION_STEP];
134 	char *token_array[8], output[] = RESULT_FILE_NAME, temp[512];
135 	int runs;
136 	FILE *fp;
137 
138 	fp = fopen(output, "r");
139 	if (!fp) {
140 		ksft_perror(output);
141 
142 		return -1;
143 	}
144 
145 	runs = 0;
146 	while (fgets(temp, sizeof(temp), fp)) {
147 		char *token = strtok(temp, ":\t");
148 		int fields = 0;
149 
150 		while (token) {
151 			token_array[fields++] = token;
152 			token = strtok(NULL, ":\t");
153 		}
154 
155 		/* Field 3 is perf imc value */
156 		bw_imc[runs] = strtoul(token_array[3], NULL, 0);
157 		/* Field 5 is resctrl value */
158 		bw_resc[runs] = strtoul(token_array[5], NULL, 0);
159 		runs++;
160 	}
161 
162 	fclose(fp);
163 
164 	return show_mba_info(bw_imc, bw_resc);
165 }
166 
167 static void mba_test_cleanup(void)
168 {
169 	remove(RESULT_FILE_NAME);
170 }
171 
172 static int mba_run_test(const struct resctrl_test *test, const struct user_params *uparams)
173 {
174 	struct resctrl_val_param param = {
175 		.ctrlgrp	= "c1",
176 		.filename	= RESULT_FILE_NAME,
177 		.init		= mba_init,
178 		.setup		= mba_setup,
179 		.measure	= mba_measure,
180 	};
181 	struct fill_buf_param fill_buf = {};
182 	int ret;
183 
184 	remove(RESULT_FILE_NAME);
185 
186 	if (uparams->fill_buf) {
187 		fill_buf.buf_size = uparams->fill_buf->buf_size;
188 		fill_buf.memflush = uparams->fill_buf->memflush;
189 		param.fill_buf = &fill_buf;
190 	} else if (!uparams->benchmark_cmd[0]) {
191 		ssize_t buf_size;
192 
193 		buf_size = get_fill_buf_size(uparams->cpu, "L3");
194 		if (buf_size < 0)
195 			return buf_size;
196 		fill_buf.buf_size = buf_size;
197 		fill_buf.memflush = true;
198 		param.fill_buf = &fill_buf;
199 	}
200 
201 	ret = resctrl_val(test, uparams, &param);
202 	if (ret)
203 		return ret;
204 
205 	ret = check_results();
206 	if (ret && (get_vendor() == ARCH_INTEL) && !snc_kernel_support())
207 		ksft_print_msg("Kernel doesn't support Sub-NUMA Clustering but it is enabled on the system.\n");
208 
209 	return ret;
210 }
211 
212 static bool mba_feature_check(const struct resctrl_test *test)
213 {
214 	return test_resource_feature_check(test) &&
215 	       resctrl_mon_feature_exists("L3_MON", "mbm_local_bytes");
216 }
217 
218 struct resctrl_test mba_test = {
219 	.name = "MBA",
220 	.resource = "MB",
221 	.vendor_specific = ARCH_INTEL,
222 	.feature_check = mba_feature_check,
223 	.run_test = mba_run_test,
224 	.cleanup = mba_test_cleanup,
225 };
226