1 // SPDX-License-Identifier: GPL-2.0
5 #include "parse-events.h"
10 #include <subcmd/parse-options.h>
11 #include <perf/cpumap.h>
14 #include "../perf-sys.h"
16 typedef void (*setup_probe_fn_t)(struct evsel *evsel);
18 static int perf_do_probe_api(setup_probe_fn_t fn, int cpu, const char *str)
20 struct evlist *evlist;
22 unsigned long flags = perf_event_open_cloexec_flag();
23 int err = -EAGAIN, fd;
24 static pid_t pid = -1;
26 evlist = evlist__new();
30 if (parse_events(evlist, str, NULL))
33 evsel = evlist__first(evlist);
36 fd = sys_perf_event_open(&evsel->core.attr, pid, cpu, -1, flags);
38 if (pid == -1 && errno == EACCES) {
50 fd = sys_perf_event_open(&evsel->core.attr, pid, cpu, -1, flags);
60 evlist__delete(evlist);
64 static bool perf_probe_api(setup_probe_fn_t fn)
66 const char *try[] = {"cycles:u", "instructions:u", "cpu-clock:u", NULL};
67 struct perf_cpu_map *cpus;
70 cpus = perf_cpu_map__new(NULL);
74 perf_cpu_map__put(cpus);
77 ret = perf_do_probe_api(fn, cpu, try[i++]);
80 } while (ret == -EAGAIN && try[i]);
85 static void perf_probe_sample_identifier(struct evsel *evsel)
87 evsel->core.attr.sample_type |= PERF_SAMPLE_IDENTIFIER;
90 static void perf_probe_comm_exec(struct evsel *evsel)
92 evsel->core.attr.comm_exec = 1;
95 static void perf_probe_context_switch(struct evsel *evsel)
97 evsel->core.attr.context_switch = 1;
100 bool perf_can_sample_identifier(void)
102 return perf_probe_api(perf_probe_sample_identifier);
105 static bool perf_can_comm_exec(void)
107 return perf_probe_api(perf_probe_comm_exec);
110 bool perf_can_record_switch_events(void)
112 return perf_probe_api(perf_probe_context_switch);
115 bool perf_can_record_cpu_wide(void)
117 struct perf_event_attr attr = {
118 .type = PERF_TYPE_SOFTWARE,
119 .config = PERF_COUNT_SW_CPU_CLOCK,
122 struct perf_cpu_map *cpus;
125 cpus = perf_cpu_map__new(NULL);
129 perf_cpu_map__put(cpus);
131 fd = sys_perf_event_open(&attr, -1, cpu, -1, 0);
139 void perf_evlist__config(struct evlist *evlist, struct record_opts *opts,
140 struct callchain_param *callchain)
143 bool use_sample_identifier = false;
145 bool sample_id = opts->sample_id;
148 * Set the evsel leader links before we configure attributes,
149 * since some might depend on this info.
152 perf_evlist__set_leader(evlist);
154 if (evlist->core.cpus->map[0] < 0)
155 opts->no_inherit = true;
157 use_comm_exec = perf_can_comm_exec();
159 evlist__for_each_entry(evlist, evsel) {
160 perf_evsel__config(evsel, opts, callchain);
161 if (evsel->tracking && use_comm_exec)
162 evsel->core.attr.comm_exec = 1;
165 if (opts->full_auxtrace) {
167 * Need to be able to synthesize and parse selected events with
168 * arbitrary sample types, which requires always being able to
171 use_sample_identifier = perf_can_sample_identifier();
173 } else if (evlist->core.nr_entries > 1) {
174 struct evsel *first = evlist__first(evlist);
176 evlist__for_each_entry(evlist, evsel) {
177 if (evsel->core.attr.sample_type == first->core.attr.sample_type)
179 use_sample_identifier = perf_can_sample_identifier();
186 evlist__for_each_entry(evlist, evsel)
187 perf_evsel__set_sample_id(evsel, use_sample_identifier);
190 perf_evlist__set_id_pos(evlist);
193 static int get_max_rate(unsigned int *rate)
195 return sysctl__read_int("kernel/perf_event_max_sample_rate", (int *)rate);
198 static int record_opts__config_freq(struct record_opts *opts)
200 bool user_freq = opts->user_freq != UINT_MAX;
201 unsigned int max_rate;
203 if (opts->user_interval != ULLONG_MAX)
204 opts->default_interval = opts->user_interval;
206 opts->freq = opts->user_freq;
209 * User specified count overrides default frequency.
211 if (opts->default_interval)
213 else if (opts->freq) {
214 opts->default_interval = opts->freq;
216 pr_err("frequency and count are zero, aborting\n");
220 if (get_max_rate(&max_rate))
224 * User specified frequency is over current maximum.
226 if (user_freq && (max_rate < opts->freq)) {
227 if (opts->strict_freq) {
228 pr_err("error: Maximum frequency rate (%'u Hz) exceeded.\n"
229 " Please use -F freq option with a lower value or consider\n"
230 " tweaking /proc/sys/kernel/perf_event_max_sample_rate.\n",
234 pr_warning("warning: Maximum frequency rate (%'u Hz) exceeded, throttling from %'u Hz to %'u Hz.\n"
235 " The limit can be raised via /proc/sys/kernel/perf_event_max_sample_rate.\n"
236 " The kernel will lower it when perf's interrupts take too long.\n"
237 " Use --strict-freq to disable this throttling, refusing to record.\n",
238 max_rate, opts->freq, max_rate);
240 opts->freq = max_rate;
245 * Default frequency is over current maximum.
247 if (max_rate < opts->freq) {
248 pr_warning("Lowering default frequency rate to %u.\n"
249 "Please consider tweaking "
250 "/proc/sys/kernel/perf_event_max_sample_rate.\n",
252 opts->freq = max_rate;
258 int record_opts__config(struct record_opts *opts)
260 return record_opts__config_freq(opts);
263 bool perf_evlist__can_select_event(struct evlist *evlist, const char *str)
265 struct evlist *temp_evlist;
271 temp_evlist = evlist__new();
275 err = parse_events(temp_evlist, str, NULL);
279 evsel = evlist__last(temp_evlist);
281 if (!evlist || perf_cpu_map__empty(evlist->core.cpus)) {
282 struct perf_cpu_map *cpus = perf_cpu_map__new(NULL);
284 cpu = cpus ? cpus->map[0] : 0;
285 perf_cpu_map__put(cpus);
287 cpu = evlist->core.cpus->map[0];
291 fd = sys_perf_event_open(&evsel->core.attr, pid, cpu, -1,
292 perf_event_open_cloexec_flag());
294 if (pid == -1 && errno == EACCES) {
306 evlist__delete(temp_evlist);
310 int record__parse_freq(const struct option *opt, const char *str, int unset __maybe_unused)
313 struct record_opts *opts = opt->value;
318 if (strcasecmp(str, "max") == 0) {
319 if (get_max_rate(&freq)) {
320 pr_err("couldn't read /proc/sys/kernel/perf_event_max_sample_rate\n");
323 pr_info("info: Using a maximum frequency rate of %'d Hz\n", freq);
328 opts->user_freq = freq;