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
show_cache_info(unsigned long sum_llc_perf_miss,int no_of_bits,unsigned long span)55 static void show_cache_info(unsigned long sum_llc_perf_miss, int no_of_bits,
56 unsigned long span)
57 {
58 unsigned long allocated_cache_lines = span / 64;
59 unsigned long avg_llc_perf_miss = 0;
60 float diff_percent;
61
62 avg_llc_perf_miss = sum_llc_perf_miss / (NUM_OF_RUNS - 1);
63 diff_percent = ((float)allocated_cache_lines - avg_llc_perf_miss) /
64 allocated_cache_lines * 100;
65
66 printf("%sok CAT: cache miss rate within %d%%\n",
67 !is_amd && abs((int)diff_percent) > MAX_DIFF_PERCENT ?
68 "not " : "", MAX_DIFF_PERCENT);
69 tests_run++;
70 printf("# Percent diff=%d\n", abs((int)diff_percent));
71 printf("# Number of bits: %d\n", no_of_bits);
72 printf("# Avg_llc_perf_miss: %lu\n", avg_llc_perf_miss);
73 printf("# Allocated cache lines: %lu\n", allocated_cache_lines);
74 }
75
check_results(struct resctrl_val_param * param)76 static int check_results(struct resctrl_val_param *param)
77 {
78 char *token_array[8], temp[512];
79 unsigned long sum_llc_perf_miss = 0;
80 int runs = 0, no_of_bits = 0;
81 FILE *fp;
82
83 printf("# Checking for pass/fail\n");
84 fp = fopen(param->filename, "r");
85 if (!fp) {
86 perror("# Cannot open file");
87
88 return errno;
89 }
90
91 while (fgets(temp, sizeof(temp), fp)) {
92 char *token = strtok(temp, ":\t");
93 int fields = 0;
94
95 while (token) {
96 token_array[fields++] = token;
97 token = strtok(NULL, ":\t");
98 }
99 /*
100 * Discard the first value which is inaccurate due to monitoring
101 * setup transition phase.
102 */
103 if (runs > 0)
104 sum_llc_perf_miss += strtoul(token_array[3], NULL, 0);
105 runs++;
106 }
107
108 fclose(fp);
109 no_of_bits = count_bits(param->mask);
110
111 show_cache_info(sum_llc_perf_miss, no_of_bits, param->span);
112
113 return 0;
114 }
115
cat_test_cleanup(void)116 void cat_test_cleanup(void)
117 {
118 remove(RESULT_FILE_NAME1);
119 remove(RESULT_FILE_NAME2);
120 }
121
cat_perf_miss_val(int cpu_no,int n,char * cache_type)122 int cat_perf_miss_val(int cpu_no, int n, char *cache_type)
123 {
124 unsigned long l_mask, l_mask_1;
125 int ret, pipefd[2], sibling_cpu_no;
126 char pipe_message;
127 pid_t bm_pid;
128
129 cache_size = 0;
130
131 ret = remount_resctrlfs(true);
132 if (ret)
133 return ret;
134
135 if (!validate_resctrl_feature_request("cat"))
136 return -1;
137
138 /* Get default cbm mask for L3/L2 cache */
139 ret = get_cbm_mask(cache_type, cbm_mask);
140 if (ret)
141 return ret;
142
143 long_mask = strtoul(cbm_mask, NULL, 16);
144
145 /* Get L3/L2 cache size */
146 ret = get_cache_size(cpu_no, cache_type, &cache_size);
147 if (ret)
148 return ret;
149 printf("cache size :%lu\n", cache_size);
150
151 /* Get max number of bits from default-cabm mask */
152 count_of_bits = count_bits(long_mask);
153
154 if (n < 1 || n > count_of_bits - 1) {
155 printf("Invalid input value for no_of_bits n!\n");
156 printf("Please Enter value in range 1 to %d\n",
157 count_of_bits - 1);
158 return -1;
159 }
160
161 /* Get core id from same socket for running another thread */
162 sibling_cpu_no = get_core_sibling(cpu_no);
163 if (sibling_cpu_no < 0)
164 return -1;
165
166 struct resctrl_val_param param = {
167 .resctrl_val = CAT_STR,
168 .cpu_no = cpu_no,
169 .mum_resctrlfs = 0,
170 .setup = cat_setup,
171 };
172
173 l_mask = long_mask >> n;
174 l_mask_1 = ~l_mask & long_mask;
175
176 /* Set param values for parent thread which will be allocated bitmask
177 * with (max_bits - n) bits
178 */
179 param.span = cache_size * (count_of_bits - n) / count_of_bits;
180 strcpy(param.ctrlgrp, "c2");
181 strcpy(param.mongrp, "m2");
182 strcpy(param.filename, RESULT_FILE_NAME2);
183 param.mask = l_mask;
184 param.num_of_runs = 0;
185
186 if (pipe(pipefd)) {
187 perror("# Unable to create pipe");
188 return errno;
189 }
190
191 bm_pid = fork();
192
193 /* Set param values for child thread which will be allocated bitmask
194 * with n bits
195 */
196 if (bm_pid == 0) {
197 param.mask = l_mask_1;
198 strcpy(param.ctrlgrp, "c1");
199 strcpy(param.mongrp, "m1");
200 param.span = cache_size * n / count_of_bits;
201 strcpy(param.filename, RESULT_FILE_NAME1);
202 param.num_of_runs = 0;
203 param.cpu_no = sibling_cpu_no;
204 }
205
206 remove(param.filename);
207
208 ret = cat_val(¶m);
209 if (ret)
210 return ret;
211
212 ret = check_results(¶m);
213 if (ret)
214 return ret;
215
216 if (bm_pid == 0) {
217 /* Tell parent that child is ready */
218 close(pipefd[0]);
219 pipe_message = 1;
220 if (write(pipefd[1], &pipe_message, sizeof(pipe_message)) <
221 sizeof(pipe_message)) {
222 close(pipefd[1]);
223 perror("# failed signaling parent process");
224 return errno;
225 }
226
227 close(pipefd[1]);
228 while (1)
229 ;
230 } else {
231 /* Parent waits for child to be ready. */
232 close(pipefd[1]);
233 pipe_message = 0;
234 while (pipe_message != 1) {
235 if (read(pipefd[0], &pipe_message,
236 sizeof(pipe_message)) < sizeof(pipe_message)) {
237 perror("# failed reading from child process");
238 break;
239 }
240 }
241 close(pipefd[0]);
242 kill(bm_pid, SIGKILL);
243 }
244
245 cat_test_cleanup();
246 if (bm_pid)
247 umount_resctrlfs();
248
249 return 0;
250 }
251