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 static int count_of_bits;
21 static char cbm_mask[256];
22 static unsigned long long_mask;
23 static unsigned long cache_size;
24
25 /*
26 * Change schemata. Write schemata to specified
27 * con_mon grp, mon_grp in resctrl FS.
28 * Run 5 times in order to get average values.
29 */
cat_setup(int num,...)30 static int cat_setup(int num, ...)
31 {
32 struct resctrl_val_param *p;
33 char schemata[64];
34 va_list param;
35 int ret = 0;
36
37 va_start(param, num);
38 p = va_arg(param, struct resctrl_val_param *);
39 va_end(param);
40
41 /* Run NUM_OF_RUNS times */
42 if (p->num_of_runs >= NUM_OF_RUNS)
43 return -1;
44
45 if (p->num_of_runs == 0) {
46 sprintf(schemata, "%lx", p->mask);
47 ret = write_schemata(p->ctrlgrp, schemata, p->cpu_no,
48 p->resctrl_val);
49 }
50 p->num_of_runs++;
51
52 return ret;
53 }
54
check_results(struct resctrl_val_param * param)55 static int check_results(struct resctrl_val_param *param)
56 {
57 char *token_array[8], temp[512];
58 unsigned long sum_llc_perf_miss = 0;
59 int runs = 0, no_of_bits = 0;
60 FILE *fp;
61
62 ksft_print_msg("Checking for pass/fail\n");
63 fp = fopen(param->filename, "r");
64 if (!fp) {
65 perror("# Cannot open file");
66
67 return errno;
68 }
69
70 while (fgets(temp, sizeof(temp), fp)) {
71 char *token = strtok(temp, ":\t");
72 int fields = 0;
73
74 while (token) {
75 token_array[fields++] = token;
76 token = strtok(NULL, ":\t");
77 }
78 /*
79 * Discard the first value which is inaccurate due to monitoring
80 * setup transition phase.
81 */
82 if (runs > 0)
83 sum_llc_perf_miss += strtoul(token_array[3], NULL, 0);
84 runs++;
85 }
86
87 fclose(fp);
88 no_of_bits = count_bits(param->mask);
89
90 return show_cache_info(sum_llc_perf_miss, no_of_bits, param->span / 64,
91 MAX_DIFF, MAX_DIFF_PERCENT, NUM_OF_RUNS,
92 !is_amd, false);
93 }
94
cat_test_cleanup(void)95 void cat_test_cleanup(void)
96 {
97 remove(RESULT_FILE_NAME1);
98 remove(RESULT_FILE_NAME2);
99 }
100
cat_perf_miss_val(int cpu_no,int n,char * cache_type)101 int cat_perf_miss_val(int cpu_no, int n, char *cache_type)
102 {
103 unsigned long l_mask, l_mask_1;
104 int ret, pipefd[2], sibling_cpu_no;
105 char pipe_message;
106 pid_t bm_pid;
107
108 cache_size = 0;
109
110 ret = remount_resctrlfs(true);
111 if (ret)
112 return ret;
113
114 /* Get default cbm mask for L3/L2 cache */
115 ret = get_cbm_mask(cache_type, cbm_mask);
116 if (ret)
117 return ret;
118
119 long_mask = strtoul(cbm_mask, NULL, 16);
120
121 /* Get L3/L2 cache size */
122 ret = get_cache_size(cpu_no, cache_type, &cache_size);
123 if (ret)
124 return ret;
125 ksft_print_msg("Cache size :%lu\n", cache_size);
126
127 /* Get max number of bits from default-cabm mask */
128 count_of_bits = count_bits(long_mask);
129
130 if (!n)
131 n = count_of_bits / 2;
132
133 if (n > count_of_bits - 1) {
134 ksft_print_msg("Invalid input value for no_of_bits n!\n");
135 ksft_print_msg("Please enter value in range 1 to %d\n",
136 count_of_bits - 1);
137 return -1;
138 }
139
140 /* Get core id from same socket for running another thread */
141 sibling_cpu_no = get_core_sibling(cpu_no);
142 if (sibling_cpu_no < 0)
143 return -1;
144
145 struct resctrl_val_param param = {
146 .resctrl_val = CAT_STR,
147 .cpu_no = cpu_no,
148 .mum_resctrlfs = 0,
149 .setup = cat_setup,
150 };
151
152 l_mask = long_mask >> n;
153 l_mask_1 = ~l_mask & long_mask;
154
155 /* Set param values for parent thread which will be allocated bitmask
156 * with (max_bits - n) bits
157 */
158 param.span = cache_size * (count_of_bits - n) / count_of_bits;
159 strcpy(param.ctrlgrp, "c2");
160 strcpy(param.mongrp, "m2");
161 strcpy(param.filename, RESULT_FILE_NAME2);
162 param.mask = l_mask;
163 param.num_of_runs = 0;
164
165 if (pipe(pipefd)) {
166 perror("# Unable to create pipe");
167 return errno;
168 }
169
170 bm_pid = fork();
171
172 /* Set param values for child thread which will be allocated bitmask
173 * with n bits
174 */
175 if (bm_pid == 0) {
176 param.mask = l_mask_1;
177 strcpy(param.ctrlgrp, "c1");
178 strcpy(param.mongrp, "m1");
179 param.span = cache_size * n / count_of_bits;
180 strcpy(param.filename, RESULT_FILE_NAME1);
181 param.num_of_runs = 0;
182 param.cpu_no = sibling_cpu_no;
183 }
184
185 remove(param.filename);
186
187 ret = cat_val(¶m);
188 if (ret)
189 return ret;
190
191 ret = check_results(¶m);
192 if (ret)
193 return ret;
194
195 if (bm_pid == 0) {
196 /* Tell parent that child is ready */
197 close(pipefd[0]);
198 pipe_message = 1;
199 if (write(pipefd[1], &pipe_message, sizeof(pipe_message)) <
200 sizeof(pipe_message)) {
201 close(pipefd[1]);
202 perror("# failed signaling parent process");
203 return errno;
204 }
205
206 close(pipefd[1]);
207 while (1)
208 ;
209 } else {
210 /* Parent waits for child to be ready. */
211 close(pipefd[1]);
212 pipe_message = 0;
213 while (pipe_message != 1) {
214 if (read(pipefd[0], &pipe_message,
215 sizeof(pipe_message)) < sizeof(pipe_message)) {
216 perror("# failed reading from child process");
217 break;
218 }
219 }
220 close(pipefd[0]);
221 kill(bm_pid, SIGKILL);
222 }
223
224 cat_test_cleanup();
225 if (bm_pid)
226 umount_resctrlfs();
227
228 return 0;
229 }
230