- 根目录:
- tools
- perf
- builtin-stat.c
/*
* builtin-stat.c
*
* Builtin stat command: Give a precise performance counters summary
* overview about any workload, CPU or specific PID.
*
* Sample output:
$ perf stat ~/hackbench 10
Time: 0.104
Performance counter stats for '/home/mingo/hackbench':
1255.538611 task clock ticks # 10.143 CPU utilization factor
54011 context switches # 0.043 M/sec
385 CPU migrations # 0.000 M/sec
17755 pagefaults # 0.014 M/sec
3808323185 CPU cycles # 3033.219 M/sec
1575111190 instructions # 1254.530 M/sec
17367895 cache references # 13.833 M/sec
7674421 cache misses # 6.112 M/sec
Wall-clock time elapsed: 123.786620 msecs
*
* Copyright (C) 2008, Red Hat Inc, Ingo Molnar <mingo@redhat.com>
*
* Improvements and fixes by:
*
* Arjan van de Ven <arjan@linux.intel.com>
* Yanmin Zhang <yanmin.zhang@intel.com>
* Wu Fengguang <fengguang.wu@intel.com>
* Mike Galbraith <efault@gmx.de>
* Paul Mackerras <paulus@samba.org>
* Jaswinder Singh Rajput <jaswinder@kernel.org>
*
* Released under the GPL v2. (and only v2, not any later version)
*/
#include "perf.h"
#include "builtin.h"
#include "util/util.h"
#include "util/parse-options.h"
#include "util/parse-events.h"
#include "util/event.h"
#include "util/evlist.h"
#include "util/evsel.h"
#include "util/debug.h"
#include "util/header.h"
#include "util/cpumap.h"
#include "util/thread.h"
#include "util/thread_map.h"
#include <sys/prctl.h>
#include <math.h>
#include <locale.h>
#define DEFAULT_SEPARATOR " "
static struct perf_event_attr default_attrs[] = {
{ .type = PERF_TYPE_SOFTWARE, .config = PERF_COUNT_SW_TASK_CLOCK },
{ .type = PERF_TYPE_SOFTWARE, .config = PERF_COUNT_SW_CONTEXT_SWITCHES },
{ .type = PERF_TYPE_SOFTWARE, .config = PERF_COUNT_SW_CPU_MIGRATIONS },
{ .type = PERF_TYPE_SOFTWARE, .config = PERF_COUNT_SW_PAGE_FAULTS },
{ .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_CPU_CYCLES },
{ .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_INSTRUCTIONS },
{ .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_BRANCH_INSTRUCTIONS },
{ .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_BRANCH_MISSES },
{ .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_CACHE_REFERENCES },
{ .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_CACHE_MISSES },
};
struct perf_evlist *evsel_list;
static bool system_wide = false;
static int run_idx = 0;
static int run_count = 1;
static bool no_inherit = false;
static bool scale = true;
static bool no_aggr = false;
static pid_t target_pid = -1;
static pid_t target_tid = -1;
static pid_t child_pid = -1;
static bool null_run = false;
static bool big_num = true;
static int big_num_opt = -1;
static const char *cpu_list;
static const char *csv_sep = NULL;
static bool csv_output = false;
static volatile int done = 0;
struct stats
{
double n, mean, M2;
};
struct perf_stat {
struct stats res_stats[3];
};
static int perf_evsel__alloc_stat_priv(struct perf_evsel *evsel)
{
evsel->priv = zalloc(sizeof(struct perf_stat));
return evsel->priv == NULL ? -ENOMEM : 0;
}
static void perf_evsel__free_stat_priv(struct perf_evsel *evsel)
{
free(evsel->priv);
evsel->priv = NULL;
}
static void update_stats(struct stats *stats, u64 val)
{
double delta;
stats->n++;
delta = val - stats->mean;
stats->mean += delta / stats->n;
stats->M2 += delta*(val - stats->mean);
}
static double avg_stats(struct stats *stats)
{
return stats->mean;
}
/*
* http://en.wikipedia.org/wiki/Algorithms_for_calculating_variance
*
* (\Sum n_i^2) - ((\Sum n_i)^2)/n
* s^2 = -------------------------------
* n - 1
*
* http://en.wikipedia.org/wiki/Stddev
*
* The std dev of the mean is related to the std dev by:
*
* s
* s_mean = -------
* sqrt(n)
*
*/
static double stddev_stats(struct stats *stats)
{
double variance = stats->M2 / (stats->n - 1);
double variance_mean = variance / stats->n;
return sqrt(variance_mean);
}
struct stats runtime_nsecs_stats[MAX_NR_CPUS];
struct stats runtime_cycles_stats[MAX_NR_CPUS];
struct stats runtime_branches_stats[MAX_NR_CPUS];
struct stats walltime_nsecs_stats;
static int create_perf_stat_counter(struct perf_evsel *evsel)
{
struct perf_event_attr *attr = &evsel->attr;
if (scale)
attr->read_format = PERF_FORMAT_TOTAL_TIME_ENABLED |
PERF_FORMAT_TOTAL_TIME_RUNNING;
attr->inherit = !no_inherit;
if (system_wide)
return perf_evsel__open_per_cpu(evsel, evsel_list->cpus, false);
if (target_pid == -1 && target_tid == -1) {
attr->disabled = 1;
attr->enable_on_exec = 1;
}
return perf_evsel__open_per_thread(evsel, evsel_list->threads, false);
}
/*
* Does the counter have nsecs as a unit?
*/
static inline int nsec_counter(struct perf_evsel *evsel)
{
if (perf_evsel__match(evsel, SOFTWARE, SW_CPU_CLOCK) ||
perf_evsel__match(evsel, SOFTWARE, SW_TASK_CLOCK))
return 1;
return 0;
}
/*
* Read out the results of a single counter:
* aggregate counts across CPUs in system-wide mode
*/
static int read_counter_aggr(struct perf_evsel *counter)
{
struct perf_stat *ps = counter->priv;
u64 *count = counter->counts->aggr.values;
int i;
if (__perf_evsel__read(counter, evsel_list->cpus->nr,
evsel_list->threads->nr, scale) < 0)
return -1;
for (i = 0; i < 3; i++)
update_stats(&ps->res_stats[i], count[i]);
if (verbose) {
fprintf(stderr, "%s: %" PRIu64 " %" PRIu64 " %" PRIu64 "\n",
event_name(counter), count[0], count[1], count[2]);
}
/*
* Save the full runtime - to allow normalization during printout:
*/
if (perf_evsel__match(counter, SOFTWARE, SW_TASK_CLOCK))
update_stats(&runtime_nsecs_stats[0], count[0]);
if (perf_evsel__match(counter, HARDWARE, HW_CPU_CYCLES))
update_stats(&runtime_cycles_stats[0], count[0]);
if (perf_evsel__match(counter, HARDWARE, HW_BRANCH_INSTRUCTIONS))
update_stats(&runtime_branches_stats[0], count[0]);
return 0;
}
/*
* Read out the results of a single counter:
* do not aggregate counts across CPUs in system-wide mode
*/
static int read_counter(struct perf_evsel *counter)
{
u64 *count;
int cpu;
for (cpu = 0; cpu < evsel_list->cpus->nr; cpu++) {
if (__perf_evsel__read_on_cpu(counter, cpu, 0, scale) < 0)
return -1;
count = counter->counts->cpu[cpu].values;
if (perf_evsel__match(counter, SOFTWARE, SW_TASK_CLOCK))
update_stats(&runtime_nsecs_stats[cpu], count[0]);
if (perf_evsel__match(counter, HARDWARE, HW_CPU_CYCLES))
update_stats(&runtime_cycles_stats[cpu], count[0]);
if (perf_evsel__match(counter, HARDWARE, HW_BRANCH_INSTRUCTIONS))
update_stats(&runtime_branches_stats[cpu], count[0]);
}
return 0;
}
static int run_perf_stat(int argc __used, const char **argv)
{
unsigned long long t0, t1;
struct perf_evsel *counter;
int status = 0;
int child_ready_pipe[2], go_pipe[2];
const bool forks = (argc > 0);
char buf;
if (forks && (pipe(child_ready_pipe) < 0 || pipe(go_pipe) < 0)) {
perror("failed to create pipes");
exit(1);
}
if (forks) {
if ((child_pid = fork()) < 0)
perror("failed to fork");
if (!child_pid) {
close(child_ready_pipe[0]);
close(go_pipe[1]);
fcntl(go_pipe[0], F_SETFD, FD_CLOEXEC);
/*
* Do a dummy execvp to get the PLT entry resolved,
* so we avoid the resolver overhead on the real
* execvp call.
*/
execvp("", (char **)argv);
/*
* Tell the parent we're ready to go
*/
close(child_ready_pipe[1]);
/*
* Wait until the parent tells us to go.
*/
if (read(go_pipe[0], &buf, 1) == -1)
perror("unable to read pipe");
execvp(argv[0], (char **)argv);
perror(argv[0]);
exit(-1);
}
if (target_tid == -1 && target_pid == -1 && !system_wide)
evsel_list->threads->map[0] = child_pid;
/*
* Wait for the child to be ready to exec.
*/
close(child_ready_pipe[1]);
close(go_pipe[0]);
if (read(child_ready_pipe[0], &buf, 1) == -1)
perror("unable to read pipe");
close(child_ready_pipe[0]);
}
list_for_each_entry(counter, &evsel_list->entries, node) {
if (create_perf_stat_counter(counter) < 0) {
if (errno == -EPERM || errno == -EACCES) {
error("You may not have permission to collect %sstats.\n"
"\t Consider tweaking"
" /proc/sys/kernel/perf_event_paranoid or running as root.",
system_wide ? "system-wide " : "");
} else if (errno == ENOENT) {
error("%s event is not supported. ", event_name(counter));
} else {
error("open_counter returned with %d (%s). "
"/bin/dmesg may provide additional information.\n",
errno, strerror(errno));
}
if (child_pid != -1)
kill(child_pid, SIGTERM);
die("Not all events could be opened.\n");
return -1;
}
}
if (perf_evlist__set_filters(evsel_list)) {
error("failed to set filter with %d (%s)\n", errno,
strerror(errno));
return -1;
}
/*
* Enable counters and exec the command:
*/
t0 = rdclock();
if (forks) {
close(go_pipe[1]);
wait(&status);
} else {
while(!done) sleep(1);
}
t1 = rdclock();
update_stats(&walltime_nsecs_stats, t1 - t0);
if (no_aggr) {
list_for_each_entry(counter, &evsel_list->entries, node) {
read_counter(counter);
perf_evsel__close_fd(counter, evsel_list->cpus->nr, 1);
}
} else {
list_for_each_entry(counter, &evsel_list->entries, node) {
read_counter_aggr(counter);
perf_evsel__close_fd(counter, evsel_list->cpus->nr,
evsel_list->threads->nr);
}
}
return WEXITSTATUS(status);
}
static void print_noise(struct perf_evsel *evsel, double avg)
{
struct perf_stat *ps;
if (run_count == 1)
return;
ps = evsel->priv;
fprintf(stderr, " ( +- %7.3f%% )",
100 * stddev_stats(&ps->res_stats[0]) / avg);
}
static void nsec_printout(int cpu, struct perf_evsel *evsel, double avg)
{
double msecs = avg / 1e6;
char cpustr[16] = { '\0', };
const char *fmt = csv_output ? "%s%.6f%s%s" : "%s%18.6f%s%-24s";
if (no_aggr)
sprintf(cpustr, "CPU%*d%s",
csv_output ? 0 : -4,
evsel_list->cpus->map[cpu], csv_sep);
fprintf(stderr, fmt, cpustr, msecs, csv_sep, event_name(evsel));
if (evsel->cgrp)
fprintf(stderr, "%s%s", csv_sep, evsel->cgrp->name);
if (csv_output)
return;
if (perf_evsel__match(evsel, SOFTWARE, SW_TASK_CLOCK))
fprintf(stderr, " # %10.3f CPUs ",
avg / avg_stats(&walltime_nsecs_stats));
}
static void abs_printout(int cpu, struct perf_evsel *evsel, double avg)
{
double total, ratio = 0.0;
char cpustr[16] = { '\0', };
const char *fmt;
if (csv_output)
fmt = "%s%.0f%s%s";
else if (big_num)
fmt = "%s%'18.0f%s%-24s";
else
fmt = "%s%18.0f%s%-24s";
if (no_aggr)
sprintf(cpustr, "CPU%*d%s",
csv_output ? 0 : -4,
evsel_list->cpus->map[cpu], csv_sep);
else
cpu = 0;
fprintf(stderr, fmt, cpustr, avg, csv_sep, event_name(evsel));
if (evsel->cgrp)
fprintf(stderr, "%s%s", csv_sep, evsel->cgrp->name);
if (csv_output)
return;
if (perf_evsel__match(evsel, HARDWARE, HW_INSTRUCTIONS)) {
total = avg_stats(&runtime_cycles_stats[cpu]);
if (total)
ratio = avg / total;
fprintf(stderr, " # %10.3f IPC ", ratio);
} else if (perf_evsel__match(evsel, HARDWARE, HW_BRANCH_MISSES) &&
runtime_branches_stats[cpu].n != 0) {
total = avg_stats(&runtime_branches_stats[cpu]);
if (total)
ratio = avg * 100 / total;
fprintf(stderr, " # %10.3f %% ", ratio);
} else if (runtime_nsecs_stats[cpu].n != 0) {
total = avg_stats(&runtime_nsecs_stats[cpu]);
if (total)
ratio = 1000.0 * avg / total;
fprintf(stderr, " # %10.3f M/sec", ratio);
}
}
/*
* Print out the results of a single counter:
* aggregated counts in system-wide mode
*/
static void print_counter_aggr(struct perf_evsel *counter)
{
struct perf_stat *ps = counter->priv;
double avg = avg_stats(&ps->res_stats[0]);
int scaled = counter->counts->scaled;
if (scaled == -1) {
fprintf(stderr, "%*s%s%*s",
csv_output ? 0 : 18,
"<not counted>",
csv_sep,
csv_output ? 0 : -24,
event_name(counter));
if (counter->cgrp)
fprintf(stderr, "%s%s", csv_sep, counter->cgrp->name);
fputc('\n', stderr);
return;
}
if (nsec_counter(counter))
nsec_printout(-1, counter, avg);
else
abs_printout(-1, counter, avg);
if (csv_output) {
fputc('\n', stderr);
return;
}
print_noise(counter, avg);
if (scaled) {
double avg_enabled, avg_running;
avg_enabled = avg_stats(&ps->res_stats[1]);
avg_running = avg_stats(&ps->res_stats[2]);
fprintf(stderr, " (scaled from %.2f%%)",
100 * avg_running / avg_enabled);
}
fprintf(stderr, "\n");
}
/*
* Print out the results of a single counter:
* does not use aggregated count in system-wide
*/
static void print_counter(struct perf_evsel *counter)
{
u64 ena, run, val;
int cpu;
for (cpu = 0; cpu < evsel_list->cpus->nr; cpu++) {
val = counter->counts->cpu[cpu].val;
ena = counter->counts->cpu[cpu].ena;
run = counter->counts->cpu[cpu].run;
if (run == 0 || ena == 0) {
fprintf(stderr, "CPU%*d%s%*s%s%*s",
csv_output ? 0 : -4,
evsel_list->cpus->map[cpu], csv_sep,
csv_output ? 0 : 18,
"<not counted>", csv_sep,
csv_output ? 0 : -24,
event_name(counter));
if (counter->cgrp)
fprintf(stderr, "%s%s", csv_sep, counter->cgrp->name);
fputc('\n', stderr);
continue;
}
if (nsec_counter(counter))
nsec_printout(cpu, counter, val);
else
abs_printout(cpu, counter, val);
if (!csv_output) {
print_noise(counter, 1.0);
if (run != ena) {
fprintf(stderr, " (scaled from %.2f%%)",
100.0 * run / ena);
}
}
fputc('\n', stderr);
}
}
static void print_stat(int argc, const char **argv)
{
struct perf_evsel *counter;
int i;
fflush(stdout);
if (!csv_output) {
fprintf(stderr, "\n");
fprintf(stderr, " Performance counter stats for ");
if(target_pid == -1 && target_tid == -1) {
fprintf(stderr, "\'%s", argv[0]);
for (i = 1; i < argc; i++)
fprintf(stderr, " %s", argv[i]);
} else if (target_pid != -1)
fprintf(stderr, "process id \'%d", target_pid);
else
fprintf(stderr, "thread id \'%d", target_tid);
fprintf(stderr, "\'");
if (run_count > 1)
fprintf(stderr, " (%d runs)", run_count);
fprintf(stderr, ":\n\n");
}
if (no_aggr) {
list_for_each_entry(counter, &evsel_list->entries, node)
print_counter(counter);
} else {
list_for_each_entry(counter, &evsel_list->entries, node)
print_counter_aggr(counter);
}
if (!csv_output) {
fprintf(stderr, "\n");
fprintf(stderr, " %18.9f seconds time elapsed",
avg_stats(&walltime_nsecs_stats)/1e9);
if (run_count > 1) {
fprintf(stderr, " ( +- %7.3f%% )",
100*stddev_stats(&walltime_nsecs_stats) /
avg_stats(&walltime_nsecs_stats));
}
fprintf(stderr, "\n\n");
}
}
static volatile int signr = -1;
static void skip_signal(int signo)
{
if(child_pid == -1)
done = 1;
signr = signo;
}
static void sig_atexit(void)
{
if (child_pid != -1)
kill(child_pid, SIGTERM);
if (signr == -1)
return;
signal(signr, SIG_DFL);
kill(getpid(), signr);
}
static const char * const stat_usage[] = {
"perf stat [<options>] [<command>]",
NULL
};
static int stat__set_big_num(const struct option *opt __used,
const char *s __used, int unset)
{
big_num_opt = unset ? 0 : 1;
return 0;
}
static const struct option options[] = {
OPT_CALLBACK('e', "event", &evsel_list, "event",
"event selector. use 'perf list' to list available events",
parse_events),
OPT_CALLBACK(0, "filter", &evsel_list, "filter",
"event filter", parse_filter),
OPT_BOOLEAN('i', "no-inherit", &no_inherit,
"child tasks do not inherit counters"),
OPT_INTEGER('p', "pid", &target_pid,
"stat events on existing process id"),
OPT_INTEGER('t', "tid", &target_tid,
"stat events on existing thread id"),
OPT_BOOLEAN('a', "all-cpus", &system_wide,
"system-wide collection from all CPUs"),
OPT_BOOLEAN('c', "scale", &scale,
"scale/normalize counters"),
OPT_INCR('v', "verbose", &verbose,
"be more verbose (show counter open errors, etc)"),
OPT_INTEGER('r', "repeat", &run_count,
"repeat command and print average + stddev (max: 100)"),
OPT_BOOLEAN('n', "null", &null_run,
"null run - dont start any counters"),
OPT_CALLBACK_NOOPT('B', "big-num", NULL, NULL,
"print large numbers with thousands\' separators",
stat__set_big_num),
OPT_STRING('C', "cpu", &cpu_list, "cpu",
"list of cpus to monitor in system-wide"),
OPT_BOOLEAN('A', "no-aggr", &no_aggr,
"disable CPU count aggregation"),
OPT_STRING('x', "field-separator", &csv_sep, "separator",
"print counts with custom separator"),
OPT_CALLBACK('G', "cgroup", &evsel_list, "name",
"monitor event in cgroup name only",
parse_cgroups),
OPT_END()
};
int cmd_stat(int argc, const char **argv, const char *prefix __used)
{
struct perf_evsel *pos;
int status = -ENOMEM;
setlocale(LC_ALL, "");
evsel_list = perf_evlist__new(NULL, NULL);
if (evsel_list == NULL)
return -ENOMEM;
argc = parse_options(argc, argv, options, stat_usage,
PARSE_OPT_STOP_AT_NON_OPTION);
if (csv_sep)
csv_output = true;
else
csv_sep = DEFAULT_SEPARATOR;
/*
* let the spreadsheet do the pretty-printing
*/
if (csv_output) {
/* User explicitely passed -B? */
if (big_num_opt == 1) {
fprintf(stderr, "-B option not supported with -x\n");
usage_with_options(stat_usage, options);
} else /* Nope, so disable big number formatting */
big_num = false;
} else if (big_num_opt == 0) /* User passed --no-big-num */
big_num = false;
if (!argc && target_pid == -1 && target_tid == -1)
usage_with_options(stat_usage, options);
if (run_count <= 0)
usage_with_options(stat_usage, options);
/* no_aggr, cgroup are for system-wide only */
if ((no_aggr || nr_cgroups) && !system_wide) {
fprintf(stderr, "both cgroup and no-aggregation "
"modes only available in system-wide mode\n");
usage_with_options(stat_usage, options);
}
/* Set attrs and nr_counters if no event is selected and !null_run */
if (!null_run && !evsel_list->nr_entries) {
size_t c;
for (c = 0; c < ARRAY_SIZE(default_attrs); ++c) {
pos = perf_evsel__new(&default_attrs[c], c);
if (pos == NULL)
goto out;
perf_evlist__add(evsel_list, pos);
}
}
if (target_pid != -1)
target_tid = target_pid;
evsel_list->threads = thread_map__new(target_pid, target_tid);
if (evsel_list->threads == NULL) {
pr_err("Problems finding threads of monitor\n");
usage_with_options(stat_usage, options);
}
if (system_wide)
evsel_list->cpus = cpu_map__new(cpu_list);
else
evsel_list->cpus = cpu_map__dummy_new();
if (evsel_list->cpus == NULL) {
perror("failed to parse CPUs map");
usage_with_options(stat_usage, options);
return -1;
}
list_for_each_entry(pos, &evsel_list->entries, node) {
if (perf_evsel__alloc_stat_priv(pos) < 0 ||
perf_evsel__alloc_counts(pos, evsel_list->cpus->nr) < 0 ||
perf_evsel__alloc_fd(pos, evsel_list->cpus->nr, evsel_list->threads->nr) < 0)
goto out_free_fd;
}
/*
* We dont want to block the signals - that would cause
* child tasks to inherit that and Ctrl-C would not work.
* What we want is for Ctrl-C to work in the exec()-ed
* task, but being ignored by perf stat itself:
*/
atexit(sig_atexit);
signal(SIGINT, skip_signal);
signal(SIGALRM, skip_signal);
signal(SIGABRT, skip_signal);
status = 0;
for (run_idx = 0; run_idx < run_count; run_idx++) {
if (run_count != 1 && verbose)
fprintf(stderr, "[ perf stat: executing run #%d ... ]\n", run_idx + 1);
status = run_perf_stat(argc, argv);
}
if (status != -1)
print_stat(argc, argv);
out_free_fd:
list_for_each_entry(pos, &evsel_list->entries, node)
perf_evsel__free_stat_priv(pos);
perf_evlist__delete_maps(evsel_list);
out:
perf_evlist__delete(evsel_list);
return status;
}