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