1 // SPDX-License-Identifier: GPL-2.0
5 #include "evsel_config.h"
6 #include "parse-events.h"
10 #include <api/fs/fs.h>
11 #include <subcmd/parse-options.h>
12 #include <perf/cpumap.h>
14 #include "util/perf_api_probe.h"
16 #include "../perf-sys.h"
20 * evsel__config_leader_sampling() uses special rules for leader sampling.
21 * However, if the leader is an AUX area event, then assume the event to sample
24 static struct evsel *evsel__read_sampler(struct evsel *evsel, struct evlist *evlist)
26 struct evsel *leader = evsel->leader;
28 if (evsel__is_aux_event(leader) || arch_topdown_sample_read(leader)) {
29 evlist__for_each_entry(evlist, evsel) {
30 if (evsel->leader == leader && evsel != evsel->leader)
38 static u64 evsel__config_term_mask(struct evsel *evsel)
40 struct evsel_config_term *term;
41 struct list_head *config_terms = &evsel->config_terms;
44 list_for_each_entry(term, config_terms, list) {
45 term_types |= 1 << term->type;
50 static void evsel__config_leader_sampling(struct evsel *evsel, struct evlist *evlist)
52 struct perf_event_attr *attr = &evsel->core.attr;
53 struct evsel *leader = evsel->leader;
54 struct evsel *read_sampler;
55 u64 term_types, freq_mask;
57 if (!leader->sample_read)
60 read_sampler = evsel__read_sampler(evsel, evlist);
62 if (evsel == read_sampler)
65 term_types = evsel__config_term_mask(evsel);
67 * Disable sampling for all group members except those with explicit
68 * config terms or the leader. In the case of an AUX area event, the 2nd
69 * event in the group is the one that 'leads' the sampling.
71 freq_mask = (1 << EVSEL__CONFIG_TERM_FREQ) | (1 << EVSEL__CONFIG_TERM_PERIOD);
72 if ((term_types & freq_mask) == 0) {
74 attr->sample_freq = 0;
75 attr->sample_period = 0;
77 if ((term_types & (1 << EVSEL__CONFIG_TERM_OVERWRITE)) == 0)
78 attr->write_backward = 0;
81 * We don't get a sample for slave events, we make them when delivering
82 * the group leader sample. Set the slave event to follow the master
83 * sample_type to ease up reporting.
84 * An AUX area event also has sample_type requirements, so also include
85 * the sample type bits from the leader's sample_type to cover that
88 attr->sample_type = read_sampler->core.attr.sample_type |
89 leader->core.attr.sample_type;
92 void perf_evlist__config(struct evlist *evlist, struct record_opts *opts,
93 struct callchain_param *callchain)
96 bool use_sample_identifier = false;
98 bool sample_id = opts->sample_id;
101 * Set the evsel leader links before we configure attributes,
102 * since some might depend on this info.
105 perf_evlist__set_leader(evlist);
107 if (evlist->core.cpus->map[0] < 0)
108 opts->no_inherit = true;
110 use_comm_exec = perf_can_comm_exec();
112 evlist__for_each_entry(evlist, evsel) {
113 evsel__config(evsel, opts, callchain);
114 if (evsel->tracking && use_comm_exec)
115 evsel->core.attr.comm_exec = 1;
118 /* Configure leader sampling here now that the sample type is known */
119 evlist__for_each_entry(evlist, evsel)
120 evsel__config_leader_sampling(evsel, evlist);
122 if (opts->full_auxtrace) {
124 * Need to be able to synthesize and parse selected events with
125 * arbitrary sample types, which requires always being able to
128 use_sample_identifier = perf_can_sample_identifier();
130 } else if (evlist->core.nr_entries > 1) {
131 struct evsel *first = evlist__first(evlist);
133 evlist__for_each_entry(evlist, evsel) {
134 if (evsel->core.attr.sample_type == first->core.attr.sample_type)
136 use_sample_identifier = perf_can_sample_identifier();
143 evlist__for_each_entry(evlist, evsel)
144 evsel__set_sample_id(evsel, use_sample_identifier);
147 perf_evlist__set_id_pos(evlist);
150 static int get_max_rate(unsigned int *rate)
152 return sysctl__read_int("kernel/perf_event_max_sample_rate", (int *)rate);
155 static int record_opts__config_freq(struct record_opts *opts)
157 bool user_freq = opts->user_freq != UINT_MAX;
158 unsigned int max_rate;
160 if (opts->user_interval != ULLONG_MAX)
161 opts->default_interval = opts->user_interval;
163 opts->freq = opts->user_freq;
166 * User specified count overrides default frequency.
168 if (opts->default_interval)
170 else if (opts->freq) {
171 opts->default_interval = opts->freq;
173 pr_err("frequency and count are zero, aborting\n");
177 if (get_max_rate(&max_rate))
181 * User specified frequency is over current maximum.
183 if (user_freq && (max_rate < opts->freq)) {
184 if (opts->strict_freq) {
185 pr_err("error: Maximum frequency rate (%'u Hz) exceeded.\n"
186 " Please use -F freq option with a lower value or consider\n"
187 " tweaking /proc/sys/kernel/perf_event_max_sample_rate.\n",
191 pr_warning("warning: Maximum frequency rate (%'u Hz) exceeded, throttling from %'u Hz to %'u Hz.\n"
192 " The limit can be raised via /proc/sys/kernel/perf_event_max_sample_rate.\n"
193 " The kernel will lower it when perf's interrupts take too long.\n"
194 " Use --strict-freq to disable this throttling, refusing to record.\n",
195 max_rate, opts->freq, max_rate);
197 opts->freq = max_rate;
202 * Default frequency is over current maximum.
204 if (max_rate < opts->freq) {
205 pr_warning("Lowering default frequency rate to %u.\n"
206 "Please consider tweaking "
207 "/proc/sys/kernel/perf_event_max_sample_rate.\n",
209 opts->freq = max_rate;
215 int record_opts__config(struct record_opts *opts)
217 return record_opts__config_freq(opts);
220 bool perf_evlist__can_select_event(struct evlist *evlist, const char *str)
222 struct evlist *temp_evlist;
228 temp_evlist = evlist__new();
232 err = parse_events(temp_evlist, str, NULL);
236 evsel = evlist__last(temp_evlist);
238 if (!evlist || perf_cpu_map__empty(evlist->core.cpus)) {
239 struct perf_cpu_map *cpus = perf_cpu_map__new(NULL);
241 cpu = cpus ? cpus->map[0] : 0;
242 perf_cpu_map__put(cpus);
244 cpu = evlist->core.cpus->map[0];
248 fd = sys_perf_event_open(&evsel->core.attr, pid, cpu, -1,
249 perf_event_open_cloexec_flag());
251 if (pid == -1 && errno == EACCES) {
263 evlist__delete(temp_evlist);
267 int record__parse_freq(const struct option *opt, const char *str, int unset __maybe_unused)
270 struct record_opts *opts = opt->value;
275 if (strcasecmp(str, "max") == 0) {
276 if (get_max_rate(&freq)) {
277 pr_err("couldn't read /proc/sys/kernel/perf_event_max_sample_rate\n");
280 pr_info("info: Using a maximum frequency rate of %'d Hz\n", freq);
285 opts->user_freq = freq;