xref: /linux/tools/testing/selftests/resctrl/cmt_test.c (revision ae22a94997b8a03dcb3c922857c203246711f9d4)
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 static int cmt_setup(const struct resctrl_test *test,
20 		     const struct user_params *uparams,
21 		     struct resctrl_val_param *p)
22 {
23 	/* Run NUM_OF_RUNS times */
24 	if (p->num_of_runs >= NUM_OF_RUNS)
25 		return END_OF_TESTS;
26 
27 	p->num_of_runs++;
28 
29 	return 0;
30 }
31 
32 static int show_results_info(unsigned long sum_llc_val, int no_of_bits,
33 			     unsigned long cache_span, unsigned long max_diff,
34 			     unsigned long max_diff_percent, unsigned long num_of_runs,
35 			     bool platform)
36 {
37 	unsigned long avg_llc_val = 0;
38 	float diff_percent;
39 	long avg_diff = 0;
40 	int ret;
41 
42 	avg_llc_val = sum_llc_val / num_of_runs;
43 	avg_diff = (long)abs(cache_span - avg_llc_val);
44 	diff_percent = ((float)cache_span - avg_llc_val) / cache_span * 100;
45 
46 	ret = platform && abs((int)diff_percent) > max_diff_percent &&
47 	      abs(avg_diff) > max_diff;
48 
49 	ksft_print_msg("%s Check cache miss rate within %lu%%\n",
50 		       ret ? "Fail:" : "Pass:", max_diff_percent);
51 
52 	ksft_print_msg("Percent diff=%d\n", abs((int)diff_percent));
53 
54 	show_cache_info(no_of_bits, avg_llc_val, cache_span, false);
55 
56 	return ret;
57 }
58 
59 static int check_results(struct resctrl_val_param *param, size_t span, int no_of_bits)
60 {
61 	char *token_array[8], temp[512];
62 	unsigned long sum_llc_occu_resc = 0;
63 	int runs = 0;
64 	FILE *fp;
65 
66 	ksft_print_msg("Checking for pass/fail\n");
67 	fp = fopen(param->filename, "r");
68 	if (!fp) {
69 		ksft_perror("Error in opening file");
70 
71 		return -1;
72 	}
73 
74 	while (fgets(temp, sizeof(temp), fp)) {
75 		char *token = strtok(temp, ":\t");
76 		int fields = 0;
77 
78 		while (token) {
79 			token_array[fields++] = token;
80 			token = strtok(NULL, ":\t");
81 		}
82 
83 		/* Field 3 is llc occ resc value */
84 		if (runs > 0)
85 			sum_llc_occu_resc += strtoul(token_array[3], NULL, 0);
86 		runs++;
87 	}
88 	fclose(fp);
89 
90 	return show_results_info(sum_llc_occu_resc, no_of_bits, span,
91 				 MAX_DIFF, MAX_DIFF_PERCENT, runs - 1, true);
92 }
93 
94 void cmt_test_cleanup(void)
95 {
96 	remove(RESULT_FILE_NAME);
97 }
98 
99 static int cmt_run_test(const struct resctrl_test *test, const struct user_params *uparams)
100 {
101 	const char * const *cmd = uparams->benchmark_cmd;
102 	const char *new_cmd[BENCHMARK_ARGS];
103 	unsigned long cache_total_size = 0;
104 	int n = uparams->bits ? : 5;
105 	unsigned long long_mask;
106 	char *span_str = NULL;
107 	int count_of_bits;
108 	size_t span;
109 	int ret, i;
110 
111 	ret = get_full_cbm("L3", &long_mask);
112 	if (ret)
113 		return ret;
114 
115 	ret = get_cache_size(uparams->cpu, "L3", &cache_total_size);
116 	if (ret)
117 		return ret;
118 	ksft_print_msg("Cache size :%lu\n", cache_total_size);
119 
120 	count_of_bits = count_bits(long_mask);
121 
122 	if (n < 1 || n > count_of_bits) {
123 		ksft_print_msg("Invalid input value for numbr_of_bits n!\n");
124 		ksft_print_msg("Please enter value in range 1 to %d\n", count_of_bits);
125 		return -1;
126 	}
127 
128 	struct resctrl_val_param param = {
129 		.resctrl_val	= CMT_STR,
130 		.ctrlgrp	= "c1",
131 		.mongrp		= "m1",
132 		.filename	= RESULT_FILE_NAME,
133 		.mask		= ~(long_mask << n) & long_mask,
134 		.num_of_runs	= 0,
135 		.setup		= cmt_setup,
136 	};
137 
138 	span = cache_portion_size(cache_total_size, param.mask, long_mask);
139 
140 	if (strcmp(cmd[0], "fill_buf") == 0) {
141 		/* Duplicate the command to be able to replace span in it */
142 		for (i = 0; uparams->benchmark_cmd[i]; i++)
143 			new_cmd[i] = uparams->benchmark_cmd[i];
144 		new_cmd[i] = NULL;
145 
146 		ret = asprintf(&span_str, "%zu", span);
147 		if (ret < 0)
148 			return -1;
149 		new_cmd[1] = span_str;
150 		cmd = new_cmd;
151 	}
152 
153 	remove(RESULT_FILE_NAME);
154 
155 	ret = resctrl_val(test, uparams, cmd, &param);
156 	if (ret)
157 		goto out;
158 
159 	ret = check_results(&param, span, n);
160 	if (ret && (get_vendor() == ARCH_INTEL))
161 		ksft_print_msg("Intel CMT may be inaccurate when Sub-NUMA Clustering is enabled. Check BIOS configuration.\n");
162 
163 out:
164 	cmt_test_cleanup();
165 	free(span_str);
166 
167 	return ret;
168 }
169 
170 static bool cmt_feature_check(const struct resctrl_test *test)
171 {
172 	return test_resource_feature_check(test) &&
173 	       resctrl_mon_feature_exists("L3_MON", "llc_occupancy");
174 }
175 
176 struct resctrl_test cmt_test = {
177 	.name = "CMT",
178 	.resource = "L3",
179 	.feature_check = cmt_feature_check,
180 	.run_test = cmt_run_test,
181 };
182