mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-25 17:05:24 +07:00
714647bdc5
Adding the check for maximum allowed frequency rate defined in following file: /proc/sys/kernel/perf_event_max_sample_rate When we cross the maximum value we fail and display detailed error message with advise. $ perf record -F 3000 ls Maximum frequency rate (2000) reached. Please use -F freq option with lower value or consider tweaking /proc/sys/kernel/perf_event_max_sample_rate. In case user does not specify the frequency and the default value cross the maximum, we display warning and set the frequency value to the current maximum. $ perf record ls Lowering default frequency rate to 2000. Please consider tweaking /proc/sys/kernel/perf_event_max_sample_rate. Same messages are used for 'perf top'. Signed-off-by: Jiri Olsa <jolsa@redhat.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1383660887-1734-4-git-send-email-jolsa@redhat.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
180 lines
3.8 KiB
C
180 lines
3.8 KiB
C
#include "evlist.h"
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#include "evsel.h"
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#include "cpumap.h"
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#include "parse-events.h"
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#include "fs.h"
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#include "util.h"
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typedef void (*setup_probe_fn_t)(struct perf_evsel *evsel);
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static int perf_do_probe_api(setup_probe_fn_t fn, int cpu, const char *str)
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{
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struct perf_evlist *evlist;
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struct perf_evsel *evsel;
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int err = -EAGAIN, fd;
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evlist = perf_evlist__new();
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if (!evlist)
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return -ENOMEM;
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if (parse_events(evlist, str))
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goto out_delete;
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evsel = perf_evlist__first(evlist);
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fd = sys_perf_event_open(&evsel->attr, -1, cpu, -1, 0);
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if (fd < 0)
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goto out_delete;
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close(fd);
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fn(evsel);
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fd = sys_perf_event_open(&evsel->attr, -1, cpu, -1, 0);
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if (fd < 0) {
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if (errno == EINVAL)
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err = -EINVAL;
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goto out_delete;
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}
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close(fd);
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err = 0;
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out_delete:
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perf_evlist__delete(evlist);
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return err;
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}
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static bool perf_probe_api(setup_probe_fn_t fn)
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{
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const char *try[] = {"cycles:u", "instructions:u", "cpu-clock", NULL};
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struct cpu_map *cpus;
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int cpu, ret, i = 0;
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cpus = cpu_map__new(NULL);
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if (!cpus)
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return false;
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cpu = cpus->map[0];
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cpu_map__delete(cpus);
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do {
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ret = perf_do_probe_api(fn, cpu, try[i++]);
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if (!ret)
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return true;
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} while (ret == -EAGAIN && try[i]);
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return false;
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}
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static void perf_probe_sample_identifier(struct perf_evsel *evsel)
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{
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evsel->attr.sample_type |= PERF_SAMPLE_IDENTIFIER;
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}
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bool perf_can_sample_identifier(void)
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{
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return perf_probe_api(perf_probe_sample_identifier);
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}
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void perf_evlist__config(struct perf_evlist *evlist,
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struct perf_record_opts *opts)
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{
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struct perf_evsel *evsel;
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bool use_sample_identifier = false;
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/*
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* Set the evsel leader links before we configure attributes,
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* since some might depend on this info.
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*/
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if (opts->group)
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perf_evlist__set_leader(evlist);
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if (evlist->cpus->map[0] < 0)
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opts->no_inherit = true;
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list_for_each_entry(evsel, &evlist->entries, node)
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perf_evsel__config(evsel, opts);
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if (evlist->nr_entries > 1) {
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struct perf_evsel *first = perf_evlist__first(evlist);
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list_for_each_entry(evsel, &evlist->entries, node) {
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if (evsel->attr.sample_type == first->attr.sample_type)
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continue;
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use_sample_identifier = perf_can_sample_identifier();
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break;
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}
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list_for_each_entry(evsel, &evlist->entries, node)
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perf_evsel__set_sample_id(evsel, use_sample_identifier);
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}
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perf_evlist__set_id_pos(evlist);
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}
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static int get_max_rate(unsigned int *rate)
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{
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char path[PATH_MAX];
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const char *procfs = procfs__mountpoint();
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if (!procfs)
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return -1;
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snprintf(path, PATH_MAX,
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"%s/sys/kernel/perf_event_max_sample_rate", procfs);
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return filename__read_int(path, (int *) rate);
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}
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static int perf_record_opts__config_freq(struct perf_record_opts *opts)
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{
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bool user_freq = opts->user_freq != UINT_MAX;
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unsigned int max_rate;
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if (opts->user_interval != ULLONG_MAX)
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opts->default_interval = opts->user_interval;
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if (user_freq)
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opts->freq = opts->user_freq;
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/*
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* User specified count overrides default frequency.
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*/
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if (opts->default_interval)
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opts->freq = 0;
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else if (opts->freq) {
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opts->default_interval = opts->freq;
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} else {
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pr_err("frequency and count are zero, aborting\n");
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return -1;
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}
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if (get_max_rate(&max_rate))
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return 0;
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/*
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* User specified frequency is over current maximum.
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*/
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if (user_freq && (max_rate < opts->freq)) {
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pr_err("Maximum frequency rate (%u) reached.\n"
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"Please use -F freq option with lower value or consider\n"
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"tweaking /proc/sys/kernel/perf_event_max_sample_rate.\n",
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max_rate);
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return -1;
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}
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/*
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* Default frequency is over current maximum.
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*/
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if (max_rate < opts->freq) {
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pr_warning("Lowering default frequency rate to %u.\n"
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"Please consider tweaking "
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"/proc/sys/kernel/perf_event_max_sample_rate.\n",
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max_rate);
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opts->freq = max_rate;
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}
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return 0;
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}
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int perf_record_opts__config(struct perf_record_opts *opts)
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{
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return perf_record_opts__config_freq(opts);
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}
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