xref: /linux/tools/testing/selftests/resctrl/cat_test.c (revision fd7d598270724cc787982ea48bbe17ad383a8b7f)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Cache Allocation Technology (CAT) 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_NAME1	"result_cat1"
15 #define RESULT_FILE_NAME2	"result_cat2"
16 #define NUM_OF_RUNS		5
17 #define MAX_DIFF_PERCENT	4
18 #define MAX_DIFF		1000000
19 
20 /*
21  * Change schemata. Write schemata to specified
22  * con_mon grp, mon_grp in resctrl FS.
23  * Run 5 times in order to get average values.
24  */
25 static int cat_setup(struct resctrl_val_param *p)
26 {
27 	char schemata[64];
28 	int ret = 0;
29 
30 	/* Run NUM_OF_RUNS times */
31 	if (p->num_of_runs >= NUM_OF_RUNS)
32 		return END_OF_TESTS;
33 
34 	if (p->num_of_runs == 0) {
35 		sprintf(schemata, "%lx", p->mask);
36 		ret = write_schemata(p->ctrlgrp, schemata, p->cpu_no,
37 				     p->resctrl_val);
38 	}
39 	p->num_of_runs++;
40 
41 	return ret;
42 }
43 
44 static int check_results(struct resctrl_val_param *param)
45 {
46 	char *token_array[8], temp[512];
47 	unsigned long sum_llc_perf_miss = 0;
48 	int runs = 0, no_of_bits = 0;
49 	FILE *fp;
50 
51 	ksft_print_msg("Checking for pass/fail\n");
52 	fp = fopen(param->filename, "r");
53 	if (!fp) {
54 		perror("# Cannot open file");
55 
56 		return errno;
57 	}
58 
59 	while (fgets(temp, sizeof(temp), fp)) {
60 		char *token = strtok(temp, ":\t");
61 		int fields = 0;
62 
63 		while (token) {
64 			token_array[fields++] = token;
65 			token = strtok(NULL, ":\t");
66 		}
67 		/*
68 		 * Discard the first value which is inaccurate due to monitoring
69 		 * setup transition phase.
70 		 */
71 		if (runs > 0)
72 			sum_llc_perf_miss += strtoul(token_array[3], NULL, 0);
73 		runs++;
74 	}
75 
76 	fclose(fp);
77 	no_of_bits = count_bits(param->mask);
78 
79 	return show_cache_info(sum_llc_perf_miss, no_of_bits, param->span / 64,
80 			       MAX_DIFF, MAX_DIFF_PERCENT, runs - 1,
81 			       get_vendor() == ARCH_INTEL, false);
82 }
83 
84 void cat_test_cleanup(void)
85 {
86 	remove(RESULT_FILE_NAME1);
87 	remove(RESULT_FILE_NAME2);
88 }
89 
90 int cat_perf_miss_val(int cpu_no, int n, char *cache_type)
91 {
92 	unsigned long l_mask, l_mask_1;
93 	int ret, pipefd[2], sibling_cpu_no;
94 	unsigned long cache_size = 0;
95 	unsigned long long_mask;
96 	char cbm_mask[256];
97 	int count_of_bits;
98 	char pipe_message;
99 
100 	/* Get default cbm mask for L3/L2 cache */
101 	ret = get_cbm_mask(cache_type, cbm_mask);
102 	if (ret)
103 		return ret;
104 
105 	long_mask = strtoul(cbm_mask, NULL, 16);
106 
107 	/* Get L3/L2 cache size */
108 	ret = get_cache_size(cpu_no, cache_type, &cache_size);
109 	if (ret)
110 		return ret;
111 	ksft_print_msg("Cache size :%lu\n", cache_size);
112 
113 	/* Get max number of bits from default-cabm mask */
114 	count_of_bits = count_bits(long_mask);
115 
116 	if (!n)
117 		n = count_of_bits / 2;
118 
119 	if (n > count_of_bits - 1) {
120 		ksft_print_msg("Invalid input value for no_of_bits n!\n");
121 		ksft_print_msg("Please enter value in range 1 to %d\n",
122 			       count_of_bits - 1);
123 		return -1;
124 	}
125 
126 	/* Get core id from same socket for running another thread */
127 	sibling_cpu_no = get_core_sibling(cpu_no);
128 	if (sibling_cpu_no < 0)
129 		return -1;
130 
131 	struct resctrl_val_param param = {
132 		.resctrl_val	= CAT_STR,
133 		.cpu_no		= cpu_no,
134 		.setup		= cat_setup,
135 	};
136 
137 	l_mask = long_mask >> n;
138 	l_mask_1 = ~l_mask & long_mask;
139 
140 	/* Set param values for parent thread which will be allocated bitmask
141 	 * with (max_bits - n) bits
142 	 */
143 	param.span = cache_size * (count_of_bits - n) / count_of_bits;
144 	strcpy(param.ctrlgrp, "c2");
145 	strcpy(param.mongrp, "m2");
146 	strcpy(param.filename, RESULT_FILE_NAME2);
147 	param.mask = l_mask;
148 	param.num_of_runs = 0;
149 
150 	if (pipe(pipefd)) {
151 		perror("# Unable to create pipe");
152 		return errno;
153 	}
154 
155 	fflush(stdout);
156 	bm_pid = fork();
157 
158 	/* Set param values for child thread which will be allocated bitmask
159 	 * with n bits
160 	 */
161 	if (bm_pid == 0) {
162 		param.mask = l_mask_1;
163 		strcpy(param.ctrlgrp, "c1");
164 		strcpy(param.mongrp, "m1");
165 		param.span = cache_size * n / count_of_bits;
166 		strcpy(param.filename, RESULT_FILE_NAME1);
167 		param.num_of_runs = 0;
168 		param.cpu_no = sibling_cpu_no;
169 	} else {
170 		ret = signal_handler_register();
171 		if (ret) {
172 			kill(bm_pid, SIGKILL);
173 			goto out;
174 		}
175 	}
176 
177 	remove(param.filename);
178 
179 	ret = cat_val(&param);
180 	if (ret == 0)
181 		ret = check_results(&param);
182 
183 	if (bm_pid == 0) {
184 		/* Tell parent that child is ready */
185 		close(pipefd[0]);
186 		pipe_message = 1;
187 		if (write(pipefd[1], &pipe_message, sizeof(pipe_message)) <
188 		    sizeof(pipe_message))
189 			/*
190 			 * Just print the error message.
191 			 * Let while(1) run and wait for itself to be killed.
192 			 */
193 			perror("# failed signaling parent process");
194 
195 		close(pipefd[1]);
196 		while (1)
197 			;
198 	} else {
199 		/* Parent waits for child to be ready. */
200 		close(pipefd[1]);
201 		pipe_message = 0;
202 		while (pipe_message != 1) {
203 			if (read(pipefd[0], &pipe_message,
204 				 sizeof(pipe_message)) < sizeof(pipe_message)) {
205 				perror("# failed reading from child process");
206 				break;
207 			}
208 		}
209 		close(pipefd[0]);
210 		kill(bm_pid, SIGKILL);
211 		signal_handler_unregister();
212 	}
213 
214 out:
215 	cat_test_cleanup();
216 
217 	return ret;
218 }
219