xref: /linux/tools/testing/selftests/resctrl/cmt_test.c (revision 7f71507851fc7764b36a3221839607d3a45c2025)
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 		sum_llc_occu_resc += strtoul(token_array[3], NULL, 0);
103 		runs++;
104 	}
105 	fclose(fp);
106 
107 	return show_results_info(sum_llc_occu_resc, no_of_bits, span,
108 				 MAX_DIFF, MAX_DIFF_PERCENT, runs, true);
109 }
110 
111 static void cmt_test_cleanup(void)
112 {
113 	remove(RESULT_FILE_NAME);
114 }
115 
116 static int cmt_run_test(const struct resctrl_test *test, const struct user_params *uparams)
117 {
118 	struct fill_buf_param fill_buf = {};
119 	unsigned long cache_total_size = 0;
120 	int n = uparams->bits ? : 5;
121 	unsigned long long_mask;
122 	int count_of_bits;
123 	size_t span;
124 	int ret;
125 
126 	ret = get_full_cbm("L3", &long_mask);
127 	if (ret)
128 		return ret;
129 
130 	ret = get_cache_size(uparams->cpu, "L3", &cache_total_size);
131 	if (ret)
132 		return ret;
133 	ksft_print_msg("Cache size :%lu\n", cache_total_size);
134 
135 	count_of_bits = count_bits(long_mask);
136 
137 	if (n < 1 || n > count_of_bits) {
138 		ksft_print_msg("Invalid input value for numbr_of_bits n!\n");
139 		ksft_print_msg("Please enter value in range 1 to %d\n", count_of_bits);
140 		return -1;
141 	}
142 
143 	struct resctrl_val_param param = {
144 		.ctrlgrp	= "c1",
145 		.filename	= RESULT_FILE_NAME,
146 		.mask		= ~(long_mask << n) & long_mask,
147 		.num_of_runs	= 0,
148 		.init		= cmt_init,
149 		.setup		= cmt_setup,
150 		.measure	= cmt_measure,
151 	};
152 
153 	span = cache_portion_size(cache_total_size, param.mask, long_mask);
154 
155 	if (uparams->fill_buf) {
156 		fill_buf.buf_size = span;
157 		fill_buf.memflush = uparams->fill_buf->memflush;
158 		param.fill_buf = &fill_buf;
159 	} else if (!uparams->benchmark_cmd[0]) {
160 		fill_buf.buf_size = span;
161 		fill_buf.memflush = true;
162 		param.fill_buf = &fill_buf;
163 	}
164 
165 	remove(RESULT_FILE_NAME);
166 
167 	ret = resctrl_val(test, uparams, &param);
168 	if (ret)
169 		return ret;
170 
171 	ret = check_results(&param, span, n);
172 	if (ret && (get_vendor() == ARCH_INTEL))
173 		ksft_print_msg("Intel CMT may be inaccurate when Sub-NUMA Clustering is enabled. Check BIOS configuration.\n");
174 
175 	return ret;
176 }
177 
178 static bool cmt_feature_check(const struct resctrl_test *test)
179 {
180 	return test_resource_feature_check(test) &&
181 	       resctrl_mon_feature_exists("L3_MON", "llc_occupancy");
182 }
183 
184 struct resctrl_test cmt_test = {
185 	.name = "CMT",
186 	.resource = "L3",
187 	.feature_check = cmt_feature_check,
188 	.run_test = cmt_run_test,
189 	.cleanup = cmt_test_cleanup,
190 };
191