1 // SPDX-License-Identifier: GPL-2.0
2
3 #include <stdint.h>
4 #include "resctrl.h"
5
6 struct read_format {
7 __u64 nr; /* The number of events */
8 struct {
9 __u64 value; /* The value of the event */
10 } values[2];
11 };
12
13 static struct perf_event_attr pea_llc_miss;
14 static struct read_format rf_cqm;
15 static int fd_lm;
16 char llc_occup_path[1024];
17
initialize_perf_event_attr(void)18 static void initialize_perf_event_attr(void)
19 {
20 pea_llc_miss.type = PERF_TYPE_HARDWARE;
21 pea_llc_miss.size = sizeof(struct perf_event_attr);
22 pea_llc_miss.read_format = PERF_FORMAT_GROUP;
23 pea_llc_miss.exclude_kernel = 1;
24 pea_llc_miss.exclude_hv = 1;
25 pea_llc_miss.exclude_idle = 1;
26 pea_llc_miss.exclude_callchain_kernel = 1;
27 pea_llc_miss.inherit = 1;
28 pea_llc_miss.exclude_guest = 1;
29 pea_llc_miss.disabled = 1;
30 }
31
ioctl_perf_event_ioc_reset_enable(void)32 static void ioctl_perf_event_ioc_reset_enable(void)
33 {
34 ioctl(fd_lm, PERF_EVENT_IOC_RESET, 0);
35 ioctl(fd_lm, PERF_EVENT_IOC_ENABLE, 0);
36 }
37
perf_event_open_llc_miss(pid_t pid,int cpu_no)38 static int perf_event_open_llc_miss(pid_t pid, int cpu_no)
39 {
40 fd_lm = perf_event_open(&pea_llc_miss, pid, cpu_no, -1,
41 PERF_FLAG_FD_CLOEXEC);
42 if (fd_lm == -1) {
43 perror("Error opening leader");
44 ctrlc_handler(0, NULL, NULL);
45 return -1;
46 }
47
48 return 0;
49 }
50
initialize_llc_perf(void)51 static int initialize_llc_perf(void)
52 {
53 memset(&pea_llc_miss, 0, sizeof(struct perf_event_attr));
54 memset(&rf_cqm, 0, sizeof(struct read_format));
55
56 /* Initialize perf_event_attr structures for HW_CACHE_MISSES */
57 initialize_perf_event_attr();
58
59 pea_llc_miss.config = PERF_COUNT_HW_CACHE_MISSES;
60
61 rf_cqm.nr = 1;
62
63 return 0;
64 }
65
reset_enable_llc_perf(pid_t pid,int cpu_no)66 static int reset_enable_llc_perf(pid_t pid, int cpu_no)
67 {
68 int ret = 0;
69
70 ret = perf_event_open_llc_miss(pid, cpu_no);
71 if (ret < 0)
72 return ret;
73
74 /* Start counters to log values */
75 ioctl_perf_event_ioc_reset_enable();
76
77 return 0;
78 }
79
80 /*
81 * get_llc_perf: llc cache miss through perf events
82 * @cpu_no: CPU number that the benchmark PID is binded to
83 *
84 * Perf events like HW_CACHE_MISSES could be used to validate number of
85 * cache lines allocated.
86 *
87 * Return: =0 on success. <0 on failure.
88 */
get_llc_perf(unsigned long * llc_perf_miss)89 static int get_llc_perf(unsigned long *llc_perf_miss)
90 {
91 __u64 total_misses;
92 int ret;
93
94 /* Stop counters after one span to get miss rate */
95
96 ioctl(fd_lm, PERF_EVENT_IOC_DISABLE, 0);
97
98 ret = read(fd_lm, &rf_cqm, sizeof(struct read_format));
99 if (ret == -1) {
100 perror("Could not get llc misses through perf");
101 return -1;
102 }
103
104 total_misses = rf_cqm.values[0].value;
105 *llc_perf_miss = total_misses;
106
107 return 0;
108 }
109
110 /*
111 * Get LLC Occupancy as reported by RESCTRL FS
112 * For CMT,
113 * 1. If con_mon grp and mon grp given, then read from mon grp in
114 * con_mon grp
115 * 2. If only con_mon grp given, then read from con_mon grp
116 * 3. If both not given, then read from root con_mon grp
117 * For CAT,
118 * 1. If con_mon grp given, then read from it
119 * 2. If con_mon grp not given, then read from root con_mon grp
120 *
121 * Return: =0 on success. <0 on failure.
122 */
get_llc_occu_resctrl(unsigned long * llc_occupancy)123 static int get_llc_occu_resctrl(unsigned long *llc_occupancy)
124 {
125 FILE *fp;
126
127 fp = fopen(llc_occup_path, "r");
128 if (!fp) {
129 perror("Failed to open results file");
130
131 return errno;
132 }
133 if (fscanf(fp, "%lu", llc_occupancy) <= 0) {
134 perror("Could not get llc occupancy");
135 fclose(fp);
136
137 return -1;
138 }
139 fclose(fp);
140
141 return 0;
142 }
143
144 /*
145 * print_results_cache: the cache results are stored in a file
146 * @filename: file that stores the results
147 * @bm_pid: child pid that runs benchmark
148 * @llc_value: perf miss value /
149 * llc occupancy value reported by resctrl FS
150 *
151 * Return: 0 on success. non-zero on failure.
152 */
print_results_cache(char * filename,int bm_pid,unsigned long llc_value)153 static int print_results_cache(char *filename, int bm_pid,
154 unsigned long llc_value)
155 {
156 FILE *fp;
157
158 if (strcmp(filename, "stdio") == 0 || strcmp(filename, "stderr") == 0) {
159 printf("Pid: %d \t LLC_value: %lu\n", bm_pid,
160 llc_value);
161 } else {
162 fp = fopen(filename, "a");
163 if (!fp) {
164 perror("Cannot open results file");
165
166 return errno;
167 }
168 fprintf(fp, "Pid: %d \t llc_value: %lu\n", bm_pid, llc_value);
169 fclose(fp);
170 }
171
172 return 0;
173 }
174
measure_cache_vals(struct resctrl_val_param * param,int bm_pid)175 int measure_cache_vals(struct resctrl_val_param *param, int bm_pid)
176 {
177 unsigned long llc_perf_miss = 0, llc_occu_resc = 0, llc_value = 0;
178 int ret;
179
180 /*
181 * Measure cache miss from perf.
182 */
183 if (!strncmp(param->resctrl_val, CAT_STR, sizeof(CAT_STR))) {
184 ret = get_llc_perf(&llc_perf_miss);
185 if (ret < 0)
186 return ret;
187 llc_value = llc_perf_miss;
188 }
189
190 /*
191 * Measure llc occupancy from resctrl.
192 */
193 if (!strncmp(param->resctrl_val, CMT_STR, sizeof(CMT_STR))) {
194 ret = get_llc_occu_resctrl(&llc_occu_resc);
195 if (ret < 0)
196 return ret;
197 llc_value = llc_occu_resc;
198 }
199 ret = print_results_cache(param->filename, bm_pid, llc_value);
200 if (ret)
201 return ret;
202
203 return 0;
204 }
205
206 /*
207 * cache_val: execute benchmark and measure LLC occupancy resctrl
208 * and perf cache miss for the benchmark
209 * @param: parameters passed to cache_val()
210 *
211 * Return: 0 on success. non-zero on failure.
212 */
cat_val(struct resctrl_val_param * param)213 int cat_val(struct resctrl_val_param *param)
214 {
215 int malloc_and_init_memory = 1, memflush = 1, operation = 0, ret = 0;
216 char *resctrl_val = param->resctrl_val;
217 pid_t bm_pid;
218
219 if (strcmp(param->filename, "") == 0)
220 sprintf(param->filename, "stdio");
221
222 bm_pid = getpid();
223
224 /* Taskset benchmark to specified cpu */
225 ret = taskset_benchmark(bm_pid, param->cpu_no);
226 if (ret)
227 return ret;
228
229 /* Write benchmark to specified con_mon grp, mon_grp in resctrl FS*/
230 ret = write_bm_pid_to_resctrl(bm_pid, param->ctrlgrp, param->mongrp,
231 resctrl_val);
232 if (ret)
233 return ret;
234
235 if (!strncmp(resctrl_val, CAT_STR, sizeof(CAT_STR))) {
236 ret = initialize_llc_perf();
237 if (ret)
238 return ret;
239 }
240
241 /* Test runs until the callback setup() tells the test to stop. */
242 while (1) {
243 if (!strncmp(resctrl_val, CAT_STR, sizeof(CAT_STR))) {
244 ret = param->setup(1, param);
245 if (ret == END_OF_TESTS) {
246 ret = 0;
247 break;
248 }
249 if (ret < 0)
250 break;
251 ret = reset_enable_llc_perf(bm_pid, param->cpu_no);
252 if (ret)
253 break;
254
255 if (run_fill_buf(param->span, malloc_and_init_memory,
256 memflush, operation, resctrl_val)) {
257 fprintf(stderr, "Error-running fill buffer\n");
258 ret = -1;
259 goto pe_close;
260 }
261
262 sleep(1);
263 ret = measure_cache_vals(param, bm_pid);
264 if (ret)
265 goto pe_close;
266
267 close(fd_lm);
268 } else {
269 break;
270 }
271 }
272
273 return ret;
274
275 pe_close:
276 close(fd_lm);
277 return ret;
278 }
279
280 /*
281 * show_cache_info: show cache test result information
282 * @sum_llc_val: sum of LLC cache result data
283 * @no_of_bits: number of bits
284 * @cache_span: cache span in bytes for CMT or in lines for CAT
285 * @max_diff: max difference
286 * @max_diff_percent: max difference percentage
287 * @num_of_runs: number of runs
288 * @platform: show test information on this platform
289 * @cmt: CMT test or CAT test
290 *
291 * Return: 0 on success. non-zero on failure.
292 */
show_cache_info(unsigned long sum_llc_val,int no_of_bits,unsigned long cache_span,unsigned long max_diff,unsigned long max_diff_percent,unsigned long num_of_runs,bool platform,bool cmt)293 int show_cache_info(unsigned long sum_llc_val, int no_of_bits,
294 unsigned long cache_span, unsigned long max_diff,
295 unsigned long max_diff_percent, unsigned long num_of_runs,
296 bool platform, bool cmt)
297 {
298 unsigned long avg_llc_val = 0;
299 float diff_percent;
300 long avg_diff = 0;
301 int ret;
302
303 avg_llc_val = sum_llc_val / (num_of_runs - 1);
304 avg_diff = (long)abs(cache_span - avg_llc_val);
305 diff_percent = ((float)cache_span - avg_llc_val) / cache_span * 100;
306
307 ret = platform && abs((int)diff_percent) > max_diff_percent &&
308 (cmt ? (abs(avg_diff) > max_diff) : true);
309
310 ksft_print_msg("%s Check cache miss rate within %d%%\n",
311 ret ? "Fail:" : "Pass:", max_diff_percent);
312
313 ksft_print_msg("Percent diff=%d\n", abs((int)diff_percent));
314 ksft_print_msg("Number of bits: %d\n", no_of_bits);
315 ksft_print_msg("Average LLC val: %lu\n", avg_llc_val);
316 ksft_print_msg("Cache span (%s): %lu\n", cmt ? "bytes" : "lines",
317 cache_span);
318
319 return ret;
320 }
321