xref: /linux/tools/testing/selftests/resctrl/cmt_test.c (revision 66e72a01b60ae6950ddbb3585fdc1424d303e14b)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Cache Monitoring Technology (CMT) 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 #include <unistd.h>
13 
14 #define RESULT_FILE_NAME	"result_cmt"
15 #define NUM_OF_RUNS		5
16 #define MAX_DIFF		2000000
17 #define MAX_DIFF_PERCENT	15
18 
19 #define CON_MON_LCC_OCCUP_PATH		\
20 	"%s/%s/mon_data/mon_L3_%02d/llc_occupancy"
21 
22 static int cmt_init(const struct resctrl_val_param *param, int domain_id)
23 {
24 	sprintf(llc_occup_path, CON_MON_LCC_OCCUP_PATH, RESCTRL_PATH,
25 		param->ctrlgrp, domain_id);
26 
27 	return 0;
28 }
29 
30 static int cmt_setup(const struct resctrl_test *test,
31 		     const struct user_params *uparams,
32 		     struct resctrl_val_param *p)
33 {
34 	/* Run NUM_OF_RUNS times */
35 	if (p->num_of_runs >= NUM_OF_RUNS)
36 		return END_OF_TESTS;
37 
38 	p->num_of_runs++;
39 
40 	return 0;
41 }
42 
43 static int cmt_measure(const struct user_params *uparams,
44 		       struct resctrl_val_param *param, pid_t bm_pid)
45 {
46 	sleep(1);
47 	return measure_llc_resctrl(param->filename, bm_pid);
48 }
49 
50 static int show_results_info(unsigned long sum_llc_val, int no_of_bits,
51 			     unsigned long cache_span, unsigned long max_diff,
52 			     unsigned long max_diff_percent, unsigned long num_of_runs,
53 			     bool platform)
54 {
55 	unsigned long avg_llc_val = 0;
56 	float diff_percent;
57 	long avg_diff = 0;
58 	int ret;
59 
60 	avg_llc_val = sum_llc_val / num_of_runs;
61 	avg_diff = (long)(cache_span - avg_llc_val);
62 	diff_percent = ((float)cache_span - avg_llc_val) / cache_span * 100;
63 
64 	ret = platform && abs((int)diff_percent) > max_diff_percent &&
65 	      labs(avg_diff) > max_diff;
66 
67 	ksft_print_msg("%s Check cache miss rate within %lu%%\n",
68 		       ret ? "Fail:" : "Pass:", max_diff_percent);
69 
70 	ksft_print_msg("Percent diff=%d\n", abs((int)diff_percent));
71 
72 	show_cache_info(no_of_bits, avg_llc_val, cache_span, false);
73 
74 	return ret;
75 }
76 
77 static int check_results(struct resctrl_val_param *param, size_t span, int no_of_bits)
78 {
79 	char *token_array[8], temp[512];
80 	unsigned long sum_llc_occu_resc = 0;
81 	int runs = 0;
82 	FILE *fp;
83 
84 	ksft_print_msg("Checking for pass/fail\n");
85 	fp = fopen(param->filename, "r");
86 	if (!fp) {
87 		ksft_perror("Error in opening file");
88 
89 		return -1;
90 	}
91 
92 	while (fgets(temp, sizeof(temp), fp)) {
93 		char *token = strtok(temp, ":\t");
94 		int fields = 0;
95 
96 		while (token) {
97 			token_array[fields++] = token;
98 			token = strtok(NULL, ":\t");
99 		}
100 
101 		/* Field 3 is llc occ resc value */
102 		if (runs > 0)
103 			sum_llc_occu_resc += strtoul(token_array[3], NULL, 0);
104 		runs++;
105 	}
106 	fclose(fp);
107 
108 	return show_results_info(sum_llc_occu_resc, no_of_bits, span,
109 				 MAX_DIFF, MAX_DIFF_PERCENT, runs - 1, true);
110 }
111 
112 static void cmt_test_cleanup(void)
113 {
114 	remove(RESULT_FILE_NAME);
115 }
116 
117 static int cmt_run_test(const struct resctrl_test *test, const struct user_params *uparams)
118 {
119 	const char * const *cmd = uparams->benchmark_cmd;
120 	const char *new_cmd[BENCHMARK_ARGS];
121 	unsigned long cache_total_size = 0;
122 	int n = uparams->bits ? : 5;
123 	unsigned long long_mask;
124 	char *span_str = NULL;
125 	int count_of_bits;
126 	size_t span;
127 	int ret, i;
128 
129 	ret = get_full_cbm("L3", &long_mask);
130 	if (ret)
131 		return ret;
132 
133 	ret = get_cache_size(uparams->cpu, "L3", &cache_total_size);
134 	if (ret)
135 		return ret;
136 	ksft_print_msg("Cache size :%lu\n", cache_total_size);
137 
138 	count_of_bits = count_bits(long_mask);
139 
140 	if (n < 1 || n > count_of_bits) {
141 		ksft_print_msg("Invalid input value for numbr_of_bits n!\n");
142 		ksft_print_msg("Please enter value in range 1 to %d\n", count_of_bits);
143 		return -1;
144 	}
145 
146 	struct resctrl_val_param param = {
147 		.ctrlgrp	= "c1",
148 		.filename	= RESULT_FILE_NAME,
149 		.mask		= ~(long_mask << n) & long_mask,
150 		.num_of_runs	= 0,
151 		.init		= cmt_init,
152 		.setup		= cmt_setup,
153 		.measure	= cmt_measure,
154 	};
155 
156 	span = cache_portion_size(cache_total_size, param.mask, long_mask);
157 
158 	if (strcmp(cmd[0], "fill_buf") == 0) {
159 		/* Duplicate the command to be able to replace span in it */
160 		for (i = 0; uparams->benchmark_cmd[i]; i++)
161 			new_cmd[i] = uparams->benchmark_cmd[i];
162 		new_cmd[i] = NULL;
163 
164 		ret = asprintf(&span_str, "%zu", span);
165 		if (ret < 0)
166 			return -1;
167 		new_cmd[1] = span_str;
168 		cmd = new_cmd;
169 	}
170 
171 	remove(RESULT_FILE_NAME);
172 
173 	ret = resctrl_val(test, uparams, cmd, &param);
174 	if (ret)
175 		goto out;
176 
177 	ret = check_results(&param, span, n);
178 	if (ret && (get_vendor() == ARCH_INTEL))
179 		ksft_print_msg("Intel CMT may be inaccurate when Sub-NUMA Clustering is enabled. Check BIOS configuration.\n");
180 
181 out:
182 	free(span_str);
183 
184 	return ret;
185 }
186 
187 static bool cmt_feature_check(const struct resctrl_test *test)
188 {
189 	return test_resource_feature_check(test) &&
190 	       resctrl_mon_feature_exists("L3_MON", "llc_occupancy");
191 }
192 
193 struct resctrl_test cmt_test = {
194 	.name = "CMT",
195 	.resource = "L3",
196 	.feature_check = cmt_feature_check,
197 	.run_test = cmt_run_test,
198 	.cleanup = cmt_test_cleanup,
199 };
200