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- // SPDX-License-Identifier: GPL-2.0
- #include "debug.h"
- #include "evlist.h"
- #include "evsel.h"
- #include "evsel_config.h"
- #include "parse-events.h"
- #include <errno.h>
- #include <limits.h>
- #include <stdlib.h>
- #include <api/fs/fs.h>
- #include <subcmd/parse-options.h>
- #include <perf/cpumap.h>
- #include "cloexec.h"
- #include "util/perf_api_probe.h"
- #include "record.h"
- #include "../perf-sys.h"
- #include "topdown.h"
- /*
- * evsel__config_leader_sampling() uses special rules for leader sampling.
- * However, if the leader is an AUX area event, then assume the event to sample
- * is the next event.
- */
- static struct evsel *evsel__read_sampler(struct evsel *evsel, struct evlist *evlist)
- {
- struct evsel *leader = evsel->leader;
- if (evsel__is_aux_event(leader) || arch_topdown_sample_read(leader)) {
- evlist__for_each_entry(evlist, evsel) {
- if (evsel->leader == leader && evsel != evsel->leader)
- return evsel;
- }
- }
- return leader;
- }
- static u64 evsel__config_term_mask(struct evsel *evsel)
- {
- struct evsel_config_term *term;
- struct list_head *config_terms = &evsel->config_terms;
- u64 term_types = 0;
- list_for_each_entry(term, config_terms, list) {
- term_types |= 1 << term->type;
- }
- return term_types;
- }
- static void evsel__config_leader_sampling(struct evsel *evsel, struct evlist *evlist)
- {
- struct perf_event_attr *attr = &evsel->core.attr;
- struct evsel *leader = evsel->leader;
- struct evsel *read_sampler;
- u64 term_types, freq_mask;
- if (!leader->sample_read)
- return;
- read_sampler = evsel__read_sampler(evsel, evlist);
- if (evsel == read_sampler)
- return;
- term_types = evsel__config_term_mask(evsel);
- /*
- * Disable sampling for all group members except those with explicit
- * config terms or the leader. In the case of an AUX area event, the 2nd
- * event in the group is the one that 'leads' the sampling.
- */
- freq_mask = (1 << EVSEL__CONFIG_TERM_FREQ) | (1 << EVSEL__CONFIG_TERM_PERIOD);
- if ((term_types & freq_mask) == 0) {
- attr->freq = 0;
- attr->sample_freq = 0;
- attr->sample_period = 0;
- }
- if ((term_types & (1 << EVSEL__CONFIG_TERM_OVERWRITE)) == 0)
- attr->write_backward = 0;
- /*
- * We don't get a sample for slave events, we make them when delivering
- * the group leader sample. Set the slave event to follow the master
- * sample_type to ease up reporting.
- * An AUX area event also has sample_type requirements, so also include
- * the sample type bits from the leader's sample_type to cover that
- * case.
- */
- attr->sample_type = read_sampler->core.attr.sample_type |
- leader->core.attr.sample_type;
- }
- void perf_evlist__config(struct evlist *evlist, struct record_opts *opts,
- struct callchain_param *callchain)
- {
- struct evsel *evsel;
- bool use_sample_identifier = false;
- bool use_comm_exec;
- bool sample_id = opts->sample_id;
- /*
- * Set the evsel leader links before we configure attributes,
- * since some might depend on this info.
- */
- if (opts->group)
- perf_evlist__set_leader(evlist);
- if (evlist->core.cpus->map[0] < 0)
- opts->no_inherit = true;
- use_comm_exec = perf_can_comm_exec();
- evlist__for_each_entry(evlist, evsel) {
- evsel__config(evsel, opts, callchain);
- if (evsel->tracking && use_comm_exec)
- evsel->core.attr.comm_exec = 1;
- }
- /* Configure leader sampling here now that the sample type is known */
- evlist__for_each_entry(evlist, evsel)
- evsel__config_leader_sampling(evsel, evlist);
- if (opts->full_auxtrace) {
- /*
- * Need to be able to synthesize and parse selected events with
- * arbitrary sample types, which requires always being able to
- * match the id.
- */
- use_sample_identifier = perf_can_sample_identifier();
- sample_id = true;
- } else if (evlist->core.nr_entries > 1) {
- struct evsel *first = evlist__first(evlist);
- evlist__for_each_entry(evlist, evsel) {
- if (evsel->core.attr.sample_type == first->core.attr.sample_type)
- continue;
- use_sample_identifier = perf_can_sample_identifier();
- break;
- }
- sample_id = true;
- }
- if (sample_id) {
- evlist__for_each_entry(evlist, evsel)
- evsel__set_sample_id(evsel, use_sample_identifier);
- }
- perf_evlist__set_id_pos(evlist);
- }
- static int get_max_rate(unsigned int *rate)
- {
- return sysctl__read_int("kernel/perf_event_max_sample_rate", (int *)rate);
- }
- static int record_opts__config_freq(struct record_opts *opts)
- {
- bool user_freq = opts->user_freq != UINT_MAX;
- unsigned int max_rate;
- if (opts->user_interval != ULLONG_MAX)
- opts->default_interval = opts->user_interval;
- if (user_freq)
- opts->freq = opts->user_freq;
- /*
- * User specified count overrides default frequency.
- */
- if (opts->default_interval)
- opts->freq = 0;
- else if (opts->freq) {
- opts->default_interval = opts->freq;
- } else {
- pr_err("frequency and count are zero, aborting\n");
- return -1;
- }
- if (get_max_rate(&max_rate))
- return 0;
- /*
- * User specified frequency is over current maximum.
- */
- if (user_freq && (max_rate < opts->freq)) {
- if (opts->strict_freq) {
- pr_err("error: Maximum frequency rate (%'u Hz) exceeded.\n"
- " Please use -F freq option with a lower value or consider\n"
- " tweaking /proc/sys/kernel/perf_event_max_sample_rate.\n",
- max_rate);
- return -1;
- } else {
- pr_warning("warning: Maximum frequency rate (%'u Hz) exceeded, throttling from %'u Hz to %'u Hz.\n"
- " The limit can be raised via /proc/sys/kernel/perf_event_max_sample_rate.\n"
- " The kernel will lower it when perf's interrupts take too long.\n"
- " Use --strict-freq to disable this throttling, refusing to record.\n",
- max_rate, opts->freq, max_rate);
- opts->freq = max_rate;
- }
- }
- /*
- * Default frequency is over current maximum.
- */
- if (max_rate < opts->freq) {
- pr_warning("Lowering default frequency rate to %u.\n"
- "Please consider tweaking "
- "/proc/sys/kernel/perf_event_max_sample_rate.\n",
- max_rate);
- opts->freq = max_rate;
- }
- return 0;
- }
- int record_opts__config(struct record_opts *opts)
- {
- return record_opts__config_freq(opts);
- }
- bool perf_evlist__can_select_event(struct evlist *evlist, const char *str)
- {
- struct evlist *temp_evlist;
- struct evsel *evsel;
- int err, fd, cpu;
- bool ret = false;
- pid_t pid = -1;
- temp_evlist = evlist__new();
- if (!temp_evlist)
- return false;
- err = parse_events(temp_evlist, str, NULL);
- if (err)
- goto out_delete;
- evsel = evlist__last(temp_evlist);
- if (!evlist || perf_cpu_map__empty(evlist->core.cpus)) {
- struct perf_cpu_map *cpus = perf_cpu_map__new(NULL);
- cpu = cpus ? cpus->map[0] : 0;
- perf_cpu_map__put(cpus);
- } else {
- cpu = evlist->core.cpus->map[0];
- }
- while (1) {
- fd = sys_perf_event_open(&evsel->core.attr, pid, cpu, -1,
- perf_event_open_cloexec_flag());
- if (fd < 0) {
- if (pid == -1 && errno == EACCES) {
- pid = 0;
- continue;
- }
- goto out_delete;
- }
- break;
- }
- close(fd);
- ret = true;
- out_delete:
- evlist__delete(temp_evlist);
- return ret;
- }
- int record__parse_freq(const struct option *opt, const char *str, int unset __maybe_unused)
- {
- unsigned int freq;
- struct record_opts *opts = opt->value;
- if (!str)
- return -EINVAL;
- if (strcasecmp(str, "max") == 0) {
- if (get_max_rate(&freq)) {
- pr_err("couldn't read /proc/sys/kernel/perf_event_max_sample_rate\n");
- return -1;
- }
- pr_info("info: Using a maximum frequency rate of %'d Hz\n", freq);
- } else {
- freq = atoi(str);
- }
- opts->user_freq = freq;
- return 0;
- }
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