GNU Linux-libre 4.14.303-gnu1
[releases.git] / tools / perf / util / record.c
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 "util.h"
9 #include "cloexec.h"
10
11 typedef void (*setup_probe_fn_t)(struct perf_evsel *evsel);
12
13 static int perf_do_probe_api(setup_probe_fn_t fn, int cpu, const char *str)
14 {
15         struct perf_evlist *evlist;
16         struct perf_evsel *evsel;
17         unsigned long flags = perf_event_open_cloexec_flag();
18         int err = -EAGAIN, fd;
19         static pid_t pid = -1;
20
21         evlist = perf_evlist__new();
22         if (!evlist)
23                 return -ENOMEM;
24
25         if (parse_events(evlist, str, NULL))
26                 goto out_delete;
27
28         evsel = perf_evlist__first(evlist);
29
30         while (1) {
31                 fd = sys_perf_event_open(&evsel->attr, pid, cpu, -1, flags);
32                 if (fd < 0) {
33                         if (pid == -1 && errno == EACCES) {
34                                 pid = 0;
35                                 continue;
36                         }
37                         goto out_delete;
38                 }
39                 break;
40         }
41         close(fd);
42
43         fn(evsel);
44
45         fd = sys_perf_event_open(&evsel->attr, pid, cpu, -1, flags);
46         if (fd < 0) {
47                 if (errno == EINVAL)
48                         err = -EINVAL;
49                 goto out_delete;
50         }
51         close(fd);
52         err = 0;
53
54 out_delete:
55         perf_evlist__delete(evlist);
56         return err;
57 }
58
59 static bool perf_probe_api(setup_probe_fn_t fn)
60 {
61         const char *try[] = {"cycles:u", "instructions:u", "cpu-clock:u", NULL};
62         struct cpu_map *cpus;
63         int cpu, ret, i = 0;
64
65         cpus = cpu_map__new(NULL);
66         if (!cpus)
67                 return false;
68         cpu = cpus->map[0];
69         cpu_map__put(cpus);
70
71         do {
72                 ret = perf_do_probe_api(fn, cpu, try[i++]);
73                 if (!ret)
74                         return true;
75         } while (ret == -EAGAIN && try[i]);
76
77         return false;
78 }
79
80 static void perf_probe_sample_identifier(struct perf_evsel *evsel)
81 {
82         evsel->attr.sample_type |= PERF_SAMPLE_IDENTIFIER;
83 }
84
85 static void perf_probe_comm_exec(struct perf_evsel *evsel)
86 {
87         evsel->attr.comm_exec = 1;
88 }
89
90 static void perf_probe_context_switch(struct perf_evsel *evsel)
91 {
92         evsel->attr.context_switch = 1;
93 }
94
95 bool perf_can_sample_identifier(void)
96 {
97         return perf_probe_api(perf_probe_sample_identifier);
98 }
99
100 static bool perf_can_comm_exec(void)
101 {
102         return perf_probe_api(perf_probe_comm_exec);
103 }
104
105 bool perf_can_record_switch_events(void)
106 {
107         return perf_probe_api(perf_probe_context_switch);
108 }
109
110 bool perf_can_record_cpu_wide(void)
111 {
112         struct perf_event_attr attr = {
113                 .type = PERF_TYPE_SOFTWARE,
114                 .config = PERF_COUNT_SW_CPU_CLOCK,
115                 .exclude_kernel = 1,
116         };
117         struct cpu_map *cpus;
118         int cpu, fd;
119
120         cpus = cpu_map__new(NULL);
121         if (!cpus)
122                 return false;
123         cpu = cpus->map[0];
124         cpu_map__put(cpus);
125
126         fd = sys_perf_event_open(&attr, -1, cpu, -1, 0);
127         if (fd < 0)
128                 return false;
129         close(fd);
130
131         return true;
132 }
133
134 void perf_evlist__config(struct perf_evlist *evlist, struct record_opts *opts,
135                          struct callchain_param *callchain)
136 {
137         struct perf_evsel *evsel;
138         bool use_sample_identifier = false;
139         bool use_comm_exec;
140
141         /*
142          * Set the evsel leader links before we configure attributes,
143          * since some might depend on this info.
144          */
145         if (opts->group)
146                 perf_evlist__set_leader(evlist);
147
148         if (evlist->cpus->map[0] < 0)
149                 opts->no_inherit = true;
150
151         use_comm_exec = perf_can_comm_exec();
152
153         evlist__for_each_entry(evlist, evsel) {
154                 perf_evsel__config(evsel, opts, callchain);
155                 if (evsel->tracking && use_comm_exec)
156                         evsel->attr.comm_exec = 1;
157         }
158
159         if (opts->full_auxtrace) {
160                 /*
161                  * Need to be able to synthesize and parse selected events with
162                  * arbitrary sample types, which requires always being able to
163                  * match the id.
164                  */
165                 use_sample_identifier = perf_can_sample_identifier();
166                 evlist__for_each_entry(evlist, evsel)
167                         perf_evsel__set_sample_id(evsel, use_sample_identifier);
168         } else if (evlist->nr_entries > 1) {
169                 struct perf_evsel *first = perf_evlist__first(evlist);
170
171                 evlist__for_each_entry(evlist, evsel) {
172                         if (evsel->attr.sample_type == first->attr.sample_type)
173                                 continue;
174                         use_sample_identifier = perf_can_sample_identifier();
175                         break;
176                 }
177                 evlist__for_each_entry(evlist, evsel)
178                         perf_evsel__set_sample_id(evsel, use_sample_identifier);
179         }
180
181         perf_evlist__set_id_pos(evlist);
182 }
183
184 static int get_max_rate(unsigned int *rate)
185 {
186         return sysctl__read_int("kernel/perf_event_max_sample_rate", (int *)rate);
187 }
188
189 static int record_opts__config_freq(struct record_opts *opts)
190 {
191         bool user_freq = opts->user_freq != UINT_MAX;
192         unsigned int max_rate;
193
194         if (opts->user_interval != ULLONG_MAX)
195                 opts->default_interval = opts->user_interval;
196         if (user_freq)
197                 opts->freq = opts->user_freq;
198
199         /*
200          * User specified count overrides default frequency.
201          */
202         if (opts->default_interval)
203                 opts->freq = 0;
204         else if (opts->freq) {
205                 opts->default_interval = opts->freq;
206         } else {
207                 pr_err("frequency and count are zero, aborting\n");
208                 return -1;
209         }
210
211         if (get_max_rate(&max_rate))
212                 return 0;
213
214         /*
215          * User specified frequency is over current maximum.
216          */
217         if (user_freq && (max_rate < opts->freq)) {
218                 pr_err("Maximum frequency rate (%u) reached.\n"
219                    "Please use -F freq option with lower value or consider\n"
220                    "tweaking /proc/sys/kernel/perf_event_max_sample_rate.\n",
221                    max_rate);
222                 return -1;
223         }
224
225         /*
226          * Default frequency is over current maximum.
227          */
228         if (max_rate < opts->freq) {
229                 pr_warning("Lowering default frequency rate to %u.\n"
230                            "Please consider tweaking "
231                            "/proc/sys/kernel/perf_event_max_sample_rate.\n",
232                            max_rate);
233                 opts->freq = max_rate;
234         }
235
236         return 0;
237 }
238
239 int record_opts__config(struct record_opts *opts)
240 {
241         return record_opts__config_freq(opts);
242 }
243
244 bool perf_evlist__can_select_event(struct perf_evlist *evlist, const char *str)
245 {
246         struct perf_evlist *temp_evlist;
247         struct perf_evsel *evsel;
248         int err, fd, cpu;
249         bool ret = false;
250         pid_t pid = -1;
251
252         temp_evlist = perf_evlist__new();
253         if (!temp_evlist)
254                 return false;
255
256         err = parse_events(temp_evlist, str, NULL);
257         if (err)
258                 goto out_delete;
259
260         evsel = perf_evlist__last(temp_evlist);
261
262         if (!evlist || cpu_map__empty(evlist->cpus)) {
263                 struct cpu_map *cpus = cpu_map__new(NULL);
264
265                 cpu =  cpus ? cpus->map[0] : 0;
266                 cpu_map__put(cpus);
267         } else {
268                 cpu = evlist->cpus->map[0];
269         }
270
271         while (1) {
272                 fd = sys_perf_event_open(&evsel->attr, pid, cpu, -1,
273                                          perf_event_open_cloexec_flag());
274                 if (fd < 0) {
275                         if (pid == -1 && errno == EACCES) {
276                                 pid = 0;
277                                 continue;
278                         }
279                         goto out_delete;
280                 }
281                 break;
282         }
283         close(fd);
284         ret = true;
285
286 out_delete:
287         perf_evlist__delete(temp_evlist);
288         return ret;
289 }