xref: /linux/tools/testing/selftests/resctrl/mbm_test.c (revision 056a5087d87ead77dedbe9cf5bde53b7cd4b4651)
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	15
15 #define NUM_OF_RUNS		5
16 
17 static int
18 show_bw_info(unsigned long *bw_imc, unsigned long *bw_resc, size_t span)
19 {
20 	unsigned long sum_bw_imc = 0, sum_bw_resc = 0;
21 	long avg_bw_imc = 0, avg_bw_resc = 0;
22 	int runs, ret, avg_diff_per;
23 	float avg_diff = 0;
24 
25 	for (runs = 0; runs < NUM_OF_RUNS; runs++) {
26 		sum_bw_imc += bw_imc[runs];
27 		sum_bw_resc += bw_resc[runs];
28 	}
29 
30 	avg_bw_imc = sum_bw_imc / NUM_OF_RUNS;
31 	avg_bw_resc = sum_bw_resc / NUM_OF_RUNS;
32 	avg_diff = (float)labs(avg_bw_resc - avg_bw_imc) / avg_bw_imc;
33 	avg_diff_per = (int)(avg_diff * 100);
34 
35 	ret = avg_diff_per > MAX_DIFF_PERCENT;
36 	ksft_print_msg("%s Check MBM diff within %d%%\n",
37 		       ret ? "Fail:" : "Pass:", MAX_DIFF_PERCENT);
38 	ksft_print_msg("avg_diff_per: %d%%\n", avg_diff_per);
39 	if (span)
40 		ksft_print_msg("Span (MB): %zu\n", span / MB);
41 	ksft_print_msg("avg_bw_imc: %lu\n", avg_bw_imc);
42 	ksft_print_msg("avg_bw_resc: %lu\n", avg_bw_resc);
43 
44 	return ret;
45 }
46 
47 static int check_results(size_t span)
48 {
49 	unsigned long bw_imc[NUM_OF_RUNS], bw_resc[NUM_OF_RUNS];
50 	char temp[1024], *token_array[8];
51 	char output[] = RESULT_FILE_NAME;
52 	int runs, ret;
53 	FILE *fp;
54 
55 	ksft_print_msg("Checking for pass/fail\n");
56 
57 	fp = fopen(output, "r");
58 	if (!fp) {
59 		ksft_perror(output);
60 
61 		return -1;
62 	}
63 
64 	runs = 0;
65 	while (fgets(temp, sizeof(temp), fp)) {
66 		char *token = strtok(temp, ":\t");
67 		int i = 0;
68 
69 		while (token) {
70 			token_array[i++] = token;
71 			token = strtok(NULL, ":\t");
72 		}
73 
74 		bw_resc[runs] = strtoul(token_array[5], NULL, 0);
75 		bw_imc[runs] = strtoul(token_array[3], NULL, 0);
76 		runs++;
77 	}
78 
79 	ret = show_bw_info(bw_imc, bw_resc, span);
80 
81 	fclose(fp);
82 
83 	return ret;
84 }
85 
86 static int mbm_init(const struct resctrl_test *test,
87 		    const struct user_params *uparams,
88 		    const struct resctrl_val_param *param, int domain_id)
89 {
90 	int ret;
91 
92 	ret = initialize_read_mem_bw_imc();
93 	if (ret)
94 		return ret;
95 
96 	initialize_mem_bw_resctrl(param, domain_id);
97 
98 	return 0;
99 }
100 
101 static int mbm_setup(const struct resctrl_test *test,
102 		     const struct user_params *uparams,
103 		     struct resctrl_val_param *p)
104 {
105 	int ret = 0;
106 
107 	/* Run NUM_OF_RUNS times */
108 	if (p->num_of_runs >= NUM_OF_RUNS)
109 		return END_OF_TESTS;
110 
111 	/* Set up shemata with 100% allocation on the first run. */
112 	if (p->num_of_runs == 0 && resctrl_resource_exists("MB"))
113 		ret = write_schemata(p->ctrlgrp, "100", uparams->cpu, test->resource);
114 
115 	p->num_of_runs++;
116 
117 	return ret;
118 }
119 
120 static int mbm_measure(const struct user_params *uparams,
121 		       struct resctrl_val_param *param, pid_t bm_pid)
122 {
123 	return measure_read_mem_bw(uparams, param, bm_pid);
124 }
125 
126 static void mbm_test_cleanup(void)
127 {
128 	remove(RESULT_FILE_NAME);
129 }
130 
131 static int mbm_run_test(const struct resctrl_test *test, const struct user_params *uparams)
132 {
133 	struct resctrl_val_param param = {
134 		.ctrlgrp	= "c1",
135 		.filename	= RESULT_FILE_NAME,
136 		.init		= mbm_init,
137 		.setup		= mbm_setup,
138 		.measure	= mbm_measure,
139 	};
140 	struct fill_buf_param fill_buf = {};
141 	int ret;
142 
143 	remove(RESULT_FILE_NAME);
144 
145 	if (uparams->fill_buf) {
146 		fill_buf.buf_size = uparams->fill_buf->buf_size;
147 		fill_buf.memflush = uparams->fill_buf->memflush;
148 		param.fill_buf = &fill_buf;
149 	} else if (!uparams->benchmark_cmd[0]) {
150 		ssize_t buf_size;
151 
152 		buf_size = get_fill_buf_size(uparams->cpu, "L3");
153 		if (buf_size < 0)
154 			return buf_size;
155 		fill_buf.buf_size = buf_size;
156 		fill_buf.memflush = true;
157 		param.fill_buf = &fill_buf;
158 	}
159 
160 	ret = resctrl_val(test, uparams, &param);
161 	if (ret)
162 		return ret;
163 
164 	ret = check_results(param.fill_buf ? param.fill_buf->buf_size : 0);
165 	if (ret && (get_vendor() == ARCH_INTEL) && !snc_kernel_support())
166 		ksft_print_msg("Kernel doesn't support Sub-NUMA Clustering but it is enabled on the system.\n");
167 
168 	return ret;
169 }
170 
171 static bool mbm_feature_check(const struct resctrl_test *test)
172 {
173 	return resctrl_mon_feature_exists("L3_MON", "mbm_total_bytes") &&
174 	       resctrl_mon_feature_exists("L3_MON", "mbm_local_bytes");
175 }
176 
177 struct resctrl_test mbm_test = {
178 	.name = "MBM",
179 	.resource = "MB",
180 	.vendor_specific = ARCH_INTEL,
181 	.feature_check = mbm_feature_check,
182 	.run_test = mbm_run_test,
183 	.cleanup = mbm_test_cleanup,
184 };
185