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"
18 #include "map_symbol.h"
19 #include "mem-events.h"
22 * evsel__config_leader_sampling() uses special rules for leader sampling.
23 * However, if the leader is an AUX area event, then assume the event to sample
26 static struct evsel *evsel__read_sampler(struct evsel *evsel, struct evlist *evlist)
28 struct evsel *leader = evsel->leader;
30 if (evsel__is_aux_event(leader) || arch_topdown_sample_read(leader) ||
31 is_mem_loads_aux_event(leader)) {
32 evlist__for_each_entry(evlist, evsel) {
33 if (evsel->leader == leader && evsel != evsel->leader)
41 static u64 evsel__config_term_mask(struct evsel *evsel)
43 struct evsel_config_term *term;
44 struct list_head *config_terms = &evsel->config_terms;
47 list_for_each_entry(term, config_terms, list) {
48 term_types |= 1 << term->type;
53 static void evsel__config_leader_sampling(struct evsel *evsel, struct evlist *evlist)
55 struct perf_event_attr *attr = &evsel->core.attr;
56 struct evsel *leader = evsel->leader;
57 struct evsel *read_sampler;
58 u64 term_types, freq_mask;
60 if (!leader->sample_read)
63 read_sampler = evsel__read_sampler(evsel, evlist);
65 if (evsel == read_sampler)
68 term_types = evsel__config_term_mask(evsel);
70 * Disable sampling for all group members except those with explicit
71 * config terms or the leader. In the case of an AUX area event, the 2nd
72 * event in the group is the one that 'leads' the sampling.
74 freq_mask = (1 << EVSEL__CONFIG_TERM_FREQ) | (1 << EVSEL__CONFIG_TERM_PERIOD);
75 if ((term_types & freq_mask) == 0) {
77 attr->sample_freq = 0;
78 attr->sample_period = 0;
80 if ((term_types & (1 << EVSEL__CONFIG_TERM_OVERWRITE)) == 0)
81 attr->write_backward = 0;
84 * We don't get a sample for slave events, we make them when delivering
85 * the group leader sample. Set the slave event to follow the master
86 * sample_type to ease up reporting.
87 * An AUX area event also has sample_type requirements, so also include
88 * the sample type bits from the leader's sample_type to cover that
91 attr->sample_type = read_sampler->core.attr.sample_type |
92 leader->core.attr.sample_type;
95 void evlist__config(struct evlist *evlist, struct record_opts *opts, struct callchain_param *callchain)
98 bool use_sample_identifier = false;
100 bool sample_id = opts->sample_id;
103 * Set the evsel leader links before we configure attributes,
104 * since some might depend on this info.
107 evlist__set_leader(evlist);
109 if (evlist->core.cpus->map[0] < 0)
110 opts->no_inherit = true;
112 use_comm_exec = perf_can_comm_exec();
114 evlist__for_each_entry(evlist, evsel) {
115 evsel__config(evsel, opts, callchain);
116 if (evsel->tracking && use_comm_exec)
117 evsel->core.attr.comm_exec = 1;
120 /* Configure leader sampling here now that the sample type is known */
121 evlist__for_each_entry(evlist, evsel)
122 evsel__config_leader_sampling(evsel, evlist);
124 if (opts->full_auxtrace) {
126 * Need to be able to synthesize and parse selected events with
127 * arbitrary sample types, which requires always being able to
130 use_sample_identifier = perf_can_sample_identifier();
132 } else if (evlist->core.nr_entries > 1) {
133 struct evsel *first = evlist__first(evlist);
135 evlist__for_each_entry(evlist, evsel) {
136 if (evsel->core.attr.sample_type == first->core.attr.sample_type)
138 use_sample_identifier = perf_can_sample_identifier();
145 evlist__for_each_entry(evlist, evsel)
146 evsel__set_sample_id(evsel, use_sample_identifier);
149 evlist__set_id_pos(evlist);
152 static int get_max_rate(unsigned int *rate)
154 return sysctl__read_int("kernel/perf_event_max_sample_rate", (int *)rate);
157 static int record_opts__config_freq(struct record_opts *opts)
159 bool user_freq = opts->user_freq != UINT_MAX;
160 bool user_interval = opts->user_interval != ULLONG_MAX;
161 unsigned int max_rate;
163 if (user_interval && user_freq) {
164 pr_err("cannot set frequency and period at the same time\n");
169 opts->default_interval = opts->user_interval;
171 opts->freq = opts->user_freq;
174 * User specified count overrides default frequency.
176 if (opts->default_interval)
178 else if (opts->freq) {
179 opts->default_interval = opts->freq;
181 pr_err("frequency and count are zero, aborting\n");
185 if (get_max_rate(&max_rate))
189 * User specified frequency is over current maximum.
191 if (user_freq && (max_rate < opts->freq)) {
192 if (opts->strict_freq) {
193 pr_err("error: Maximum frequency rate (%'u Hz) exceeded.\n"
194 " Please use -F freq option with a lower value or consider\n"
195 " tweaking /proc/sys/kernel/perf_event_max_sample_rate.\n",
199 pr_warning("warning: Maximum frequency rate (%'u Hz) exceeded, throttling from %'u Hz to %'u Hz.\n"
200 " The limit can be raised via /proc/sys/kernel/perf_event_max_sample_rate.\n"
201 " The kernel will lower it when perf's interrupts take too long.\n"
202 " Use --strict-freq to disable this throttling, refusing to record.\n",
203 max_rate, opts->freq, max_rate);
205 opts->freq = max_rate;
210 * Default frequency is over current maximum.
212 if (max_rate < opts->freq) {
213 pr_warning("Lowering default frequency rate from %u to %u.\n"
214 "Please consider tweaking "
215 "/proc/sys/kernel/perf_event_max_sample_rate.\n",
216 opts->freq, max_rate);
217 opts->freq = max_rate;
223 int record_opts__config(struct record_opts *opts)
225 return record_opts__config_freq(opts);
228 bool evlist__can_select_event(struct evlist *evlist, const char *str)
230 struct evlist *temp_evlist;
236 temp_evlist = evlist__new();
240 err = parse_events(temp_evlist, str, NULL);
244 evsel = evlist__last(temp_evlist);
246 if (!evlist || perf_cpu_map__empty(evlist->core.cpus)) {
247 struct perf_cpu_map *cpus = perf_cpu_map__new(NULL);
249 cpu = cpus ? cpus->map[0] : 0;
250 perf_cpu_map__put(cpus);
252 cpu = evlist->core.cpus->map[0];
256 fd = sys_perf_event_open(&evsel->core.attr, pid, cpu, -1,
257 perf_event_open_cloexec_flag());
259 if (pid == -1 && errno == EACCES) {
271 evlist__delete(temp_evlist);
275 int record__parse_freq(const struct option *opt, const char *str, int unset __maybe_unused)
278 struct record_opts *opts = opt->value;
283 if (strcasecmp(str, "max") == 0) {
284 if (get_max_rate(&freq)) {
285 pr_err("couldn't read /proc/sys/kernel/perf_event_max_sample_rate\n");
288 pr_info("info: Using a maximum frequency rate of %'d Hz\n", freq);
293 opts->user_freq = freq;