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1// SPDX-License-Identifier: GPL-2.0
2#include "evlist.h"
3#include "evsel.h"
4#include "cpumap.h"
5#include "parse-events.h"
6#include <errno.h>
7#include <api/fs/fs.h>
8#include <subcmd/parse-options.h>
9#include "util.h"
10#include "cloexec.h"
11
12typedef void (*setup_probe_fn_t)(struct perf_evsel *evsel);
13
14static int perf_do_probe_api(setup_probe_fn_t fn, int cpu, const char *str)
15{
16 struct perf_evlist *evlist;
17 struct perf_evsel *evsel;
18 unsigned long flags = perf_event_open_cloexec_flag();
19 int err = -EAGAIN, fd;
20 static pid_t pid = -1;
21
22 evlist = perf_evlist__new();
23 if (!evlist)
24 return -ENOMEM;
25
26 if (parse_events(evlist, str, NULL))
27 goto out_delete;
28
29 evsel = perf_evlist__first(evlist);
30
31 while (1) {
32 fd = sys_perf_event_open(&evsel->attr, pid, cpu, -1, flags);
33 if (fd < 0) {
34 if (pid == -1 && errno == EACCES) {
35 pid = 0;
36 continue;
37 }
38 goto out_delete;
39 }
40 break;
41 }
42 close(fd);
43
44 fn(evsel);
45
46 fd = sys_perf_event_open(&evsel->attr, pid, cpu, -1, flags);
47 if (fd < 0) {
48 if (errno == EINVAL)
49 err = -EINVAL;
50 goto out_delete;
51 }
52 close(fd);
53 err = 0;
54
55out_delete:
56 perf_evlist__delete(evlist);
57 return err;
58}
59
60static bool perf_probe_api(setup_probe_fn_t fn)
61{
62 const char *try[] = {"cycles:u", "instructions:u", "cpu-clock:u", NULL};
63 struct cpu_map *cpus;
64 int cpu, ret, i = 0;
65
66 cpus = cpu_map__new(NULL);
67 if (!cpus)
68 return false;
69 cpu = cpus->map[0];
70 cpu_map__put(cpus);
71
72 do {
73 ret = perf_do_probe_api(fn, cpu, try[i++]);
74 if (!ret)
75 return true;
76 } while (ret == -EAGAIN && try[i]);
77
78 return false;
79}
80
81static void perf_probe_sample_identifier(struct perf_evsel *evsel)
82{
83 evsel->attr.sample_type |= PERF_SAMPLE_IDENTIFIER;
84}
85
86static void perf_probe_comm_exec(struct perf_evsel *evsel)
87{
88 evsel->attr.comm_exec = 1;
89}
90
91static void perf_probe_context_switch(struct perf_evsel *evsel)
92{
93 evsel->attr.context_switch = 1;
94}
95
96bool perf_can_sample_identifier(void)
97{
98 return perf_probe_api(perf_probe_sample_identifier);
99}
100
101static bool perf_can_comm_exec(void)
102{
103 return perf_probe_api(perf_probe_comm_exec);
104}
105
106bool perf_can_record_switch_events(void)
107{
108 return perf_probe_api(perf_probe_context_switch);
109}
110
111bool perf_can_record_cpu_wide(void)
112{
113 struct perf_event_attr attr = {
114 .type = PERF_TYPE_SOFTWARE,
115 .config = PERF_COUNT_SW_CPU_CLOCK,
116 .exclude_kernel = 1,
117 };
118 struct cpu_map *cpus;
119 int cpu, fd;
120
121 cpus = cpu_map__new(NULL);
122 if (!cpus)
123 return false;
124 cpu = cpus->map[0];
125 cpu_map__put(cpus);
126
127 fd = sys_perf_event_open(&attr, -1, cpu, -1, 0);
128 if (fd < 0)
129 return false;
130 close(fd);
131
132 return true;
133}
134
135void perf_evlist__config(struct perf_evlist *evlist, struct record_opts *opts,
136 struct callchain_param *callchain)
137{
138 struct perf_evsel *evsel;
139 bool use_sample_identifier = false;
140 bool use_comm_exec;
141 bool sample_id = opts->sample_id;
142
143 /*
144 * Set the evsel leader links before we configure attributes,
145 * since some might depend on this info.
146 */
147 if (opts->group)
148 perf_evlist__set_leader(evlist);
149
150 if (evlist->cpus->map[0] < 0)
151 opts->no_inherit = true;
152
153 use_comm_exec = perf_can_comm_exec();
154
155 evlist__for_each_entry(evlist, evsel) {
156 perf_evsel__config(evsel, opts, callchain);
157 if (evsel->tracking && use_comm_exec)
158 evsel->attr.comm_exec = 1;
159 }
160
161 if (opts->full_auxtrace) {
162 /*
163 * Need to be able to synthesize and parse selected events with
164 * arbitrary sample types, which requires always being able to
165 * match the id.
166 */
167 use_sample_identifier = perf_can_sample_identifier();
168 sample_id = true;
169 } else if (evlist->nr_entries > 1) {
170 struct perf_evsel *first = perf_evlist__first(evlist);
171
172 evlist__for_each_entry(evlist, evsel) {
173 if (evsel->attr.sample_type == first->attr.sample_type)
174 continue;
175 use_sample_identifier = perf_can_sample_identifier();
176 break;
177 }
178 sample_id = true;
179 }
180
181 if (sample_id) {
182 evlist__for_each_entry(evlist, evsel)
183 perf_evsel__set_sample_id(evsel, use_sample_identifier);
184 }
185
186 perf_evlist__set_id_pos(evlist);
187}
188
189static int get_max_rate(unsigned int *rate)
190{
191 return sysctl__read_int("kernel/perf_event_max_sample_rate", (int *)rate);
192}
193
194static int record_opts__config_freq(struct record_opts *opts)
195{
196 bool user_freq = opts->user_freq != UINT_MAX;
197 unsigned int max_rate;
198
199 if (opts->user_interval != ULLONG_MAX)
200 opts->default_interval = opts->user_interval;
201 if (user_freq)
202 opts->freq = opts->user_freq;
203
204 /*
205 * User specified count overrides default frequency.
206 */
207 if (opts->default_interval)
208 opts->freq = 0;
209 else if (opts->freq) {
210 opts->default_interval = opts->freq;
211 } else {
212 pr_err("frequency and count are zero, aborting\n");
213 return -1;
214 }
215
216 if (get_max_rate(&max_rate))
217 return 0;
218
219 /*
220 * User specified frequency is over current maximum.
221 */
222 if (user_freq && (max_rate < opts->freq)) {
223 if (opts->strict_freq) {
224 pr_err("error: Maximum frequency rate (%'u Hz) exceeded.\n"
225 " Please use -F freq option with a lower value or consider\n"
226 " tweaking /proc/sys/kernel/perf_event_max_sample_rate.\n",
227 max_rate);
228 return -1;
229 } else {
230 pr_warning("warning: Maximum frequency rate (%'u Hz) exceeded, throttling from %'u Hz to %'u Hz.\n"
231 " The limit can be raised via /proc/sys/kernel/perf_event_max_sample_rate.\n"
232 " The kernel will lower it when perf's interrupts take too long.\n"
233 " Use --strict-freq to disable this throttling, refusing to record.\n",
234 max_rate, opts->freq, max_rate);
235
236 opts->freq = max_rate;
237 }
238 }
239
240 /*
241 * Default frequency is over current maximum.
242 */
243 if (max_rate < opts->freq) {
244 pr_warning("Lowering default frequency rate to %u.\n"
245 "Please consider tweaking "
246 "/proc/sys/kernel/perf_event_max_sample_rate.\n",
247 max_rate);
248 opts->freq = max_rate;
249 }
250
251 return 0;
252}
253
254int record_opts__config(struct record_opts *opts)
255{
256 return record_opts__config_freq(opts);
257}
258
259bool perf_evlist__can_select_event(struct perf_evlist *evlist, const char *str)
260{
261 struct perf_evlist *temp_evlist;
262 struct perf_evsel *evsel;
263 int err, fd, cpu;
264 bool ret = false;
265 pid_t pid = -1;
266
267 temp_evlist = perf_evlist__new();
268 if (!temp_evlist)
269 return false;
270
271 err = parse_events(temp_evlist, str, NULL);
272 if (err)
273 goto out_delete;
274
275 evsel = perf_evlist__last(temp_evlist);
276
277 if (!evlist || cpu_map__empty(evlist->cpus)) {
278 struct cpu_map *cpus = cpu_map__new(NULL);
279
280 cpu = cpus ? cpus->map[0] : 0;
281 cpu_map__put(cpus);
282 } else {
283 cpu = evlist->cpus->map[0];
284 }
285
286 while (1) {
287 fd = sys_perf_event_open(&evsel->attr, pid, cpu, -1,
288 perf_event_open_cloexec_flag());
289 if (fd < 0) {
290 if (pid == -1 && errno == EACCES) {
291 pid = 0;
292 continue;
293 }
294 goto out_delete;
295 }
296 break;
297 }
298 close(fd);
299 ret = true;
300
301out_delete:
302 perf_evlist__delete(temp_evlist);
303 return ret;
304}
305
306int record__parse_freq(const struct option *opt, const char *str, int unset __maybe_unused)
307{
308 unsigned int freq;
309 struct record_opts *opts = opt->value;
310
311 if (!str)
312 return -EINVAL;
313
314 if (strcasecmp(str, "max") == 0) {
315 if (get_max_rate(&freq)) {
316 pr_err("couldn't read /proc/sys/kernel/perf_event_max_sample_rate\n");
317 return -1;
318 }
319 pr_info("info: Using a maximum frequency rate of %'d Hz\n", freq);
320 } else {
321 freq = atoi(str);
322 }
323
324 opts->user_freq = freq;
325 return 0;
326}
1#include "evlist.h"
2#include "evsel.h"
3#include "cpumap.h"
4#include "parse-events.h"
5#include <api/fs/fs.h>
6#include "util.h"
7
8typedef void (*setup_probe_fn_t)(struct perf_evsel *evsel);
9
10static int perf_do_probe_api(setup_probe_fn_t fn, int cpu, const char *str)
11{
12 struct perf_evlist *evlist;
13 struct perf_evsel *evsel;
14 int err = -EAGAIN, fd;
15
16 evlist = perf_evlist__new();
17 if (!evlist)
18 return -ENOMEM;
19
20 if (parse_events(evlist, str))
21 goto out_delete;
22
23 evsel = perf_evlist__first(evlist);
24
25 fd = sys_perf_event_open(&evsel->attr, -1, cpu, -1, 0);
26 if (fd < 0)
27 goto out_delete;
28 close(fd);
29
30 fn(evsel);
31
32 fd = sys_perf_event_open(&evsel->attr, -1, cpu, -1, 0);
33 if (fd < 0) {
34 if (errno == EINVAL)
35 err = -EINVAL;
36 goto out_delete;
37 }
38 close(fd);
39 err = 0;
40
41out_delete:
42 perf_evlist__delete(evlist);
43 return err;
44}
45
46static bool perf_probe_api(setup_probe_fn_t fn)
47{
48 const char *try[] = {"cycles:u", "instructions:u", "cpu-clock", NULL};
49 struct cpu_map *cpus;
50 int cpu, ret, i = 0;
51
52 cpus = cpu_map__new(NULL);
53 if (!cpus)
54 return false;
55 cpu = cpus->map[0];
56 cpu_map__delete(cpus);
57
58 do {
59 ret = perf_do_probe_api(fn, cpu, try[i++]);
60 if (!ret)
61 return true;
62 } while (ret == -EAGAIN && try[i]);
63
64 return false;
65}
66
67static void perf_probe_sample_identifier(struct perf_evsel *evsel)
68{
69 evsel->attr.sample_type |= PERF_SAMPLE_IDENTIFIER;
70}
71
72bool perf_can_sample_identifier(void)
73{
74 return perf_probe_api(perf_probe_sample_identifier);
75}
76
77void perf_evlist__config(struct perf_evlist *evlist, struct record_opts *opts)
78{
79 struct perf_evsel *evsel;
80 bool use_sample_identifier = false;
81
82 /*
83 * Set the evsel leader links before we configure attributes,
84 * since some might depend on this info.
85 */
86 if (opts->group)
87 perf_evlist__set_leader(evlist);
88
89 if (evlist->cpus->map[0] < 0)
90 opts->no_inherit = true;
91
92 evlist__for_each(evlist, evsel)
93 perf_evsel__config(evsel, opts);
94
95 if (evlist->nr_entries > 1) {
96 struct perf_evsel *first = perf_evlist__first(evlist);
97
98 evlist__for_each(evlist, evsel) {
99 if (evsel->attr.sample_type == first->attr.sample_type)
100 continue;
101 use_sample_identifier = perf_can_sample_identifier();
102 break;
103 }
104 evlist__for_each(evlist, evsel)
105 perf_evsel__set_sample_id(evsel, use_sample_identifier);
106 }
107
108 perf_evlist__set_id_pos(evlist);
109}
110
111static int get_max_rate(unsigned int *rate)
112{
113 char path[PATH_MAX];
114 const char *procfs = procfs__mountpoint();
115
116 if (!procfs)
117 return -1;
118
119 snprintf(path, PATH_MAX,
120 "%s/sys/kernel/perf_event_max_sample_rate", procfs);
121
122 return filename__read_int(path, (int *) rate);
123}
124
125static int record_opts__config_freq(struct record_opts *opts)
126{
127 bool user_freq = opts->user_freq != UINT_MAX;
128 unsigned int max_rate;
129
130 if (opts->user_interval != ULLONG_MAX)
131 opts->default_interval = opts->user_interval;
132 if (user_freq)
133 opts->freq = opts->user_freq;
134
135 /*
136 * User specified count overrides default frequency.
137 */
138 if (opts->default_interval)
139 opts->freq = 0;
140 else if (opts->freq) {
141 opts->default_interval = opts->freq;
142 } else {
143 pr_err("frequency and count are zero, aborting\n");
144 return -1;
145 }
146
147 if (get_max_rate(&max_rate))
148 return 0;
149
150 /*
151 * User specified frequency is over current maximum.
152 */
153 if (user_freq && (max_rate < opts->freq)) {
154 pr_err("Maximum frequency rate (%u) reached.\n"
155 "Please use -F freq option with lower value or consider\n"
156 "tweaking /proc/sys/kernel/perf_event_max_sample_rate.\n",
157 max_rate);
158 return -1;
159 }
160
161 /*
162 * Default frequency is over current maximum.
163 */
164 if (max_rate < opts->freq) {
165 pr_warning("Lowering default frequency rate to %u.\n"
166 "Please consider tweaking "
167 "/proc/sys/kernel/perf_event_max_sample_rate.\n",
168 max_rate);
169 opts->freq = max_rate;
170 }
171
172 return 0;
173}
174
175int record_opts__config(struct record_opts *opts)
176{
177 return record_opts__config_freq(opts);
178}
179
180bool perf_evlist__can_select_event(struct perf_evlist *evlist, const char *str)
181{
182 struct perf_evlist *temp_evlist;
183 struct perf_evsel *evsel;
184 int err, fd, cpu;
185 bool ret = false;
186
187 temp_evlist = perf_evlist__new();
188 if (!temp_evlist)
189 return false;
190
191 err = parse_events(temp_evlist, str);
192 if (err)
193 goto out_delete;
194
195 evsel = perf_evlist__last(temp_evlist);
196
197 if (!evlist || cpu_map__empty(evlist->cpus)) {
198 struct cpu_map *cpus = cpu_map__new(NULL);
199
200 cpu = cpus ? cpus->map[0] : 0;
201 cpu_map__delete(cpus);
202 } else {
203 cpu = evlist->cpus->map[0];
204 }
205
206 fd = sys_perf_event_open(&evsel->attr, -1, cpu, -1, 0);
207 if (fd >= 0) {
208 close(fd);
209 ret = true;
210 }
211
212out_delete:
213 perf_evlist__delete(temp_evlist);
214 return ret;
215}