/* * 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 * * Improvements and fixes by: * * Arjan van de Ven * Yanmin Zhang * Wu Fengguang * Mike Galbraith * Paul Mackerras * Jaswinder Singh Rajput * * 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 #include static struct perf_counter_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_CACHE_REFERENCES}, { .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_CACHE_MISSES }, }; #define MAX_RUN 100 static int system_wide = 0; static int verbose = 0; static unsigned int nr_cpus = 0; static int run_idx = 0; static int run_count = 1; static int inherit = 1; static int scale = 1; static int target_pid = -1; static int null_run = 0; static int fd[MAX_NR_CPUS][MAX_COUNTERS]; static u64 runtime_nsecs[MAX_RUN]; static u64 walltime_nsecs[MAX_RUN]; static u64 runtime_cycles[MAX_RUN]; static u64 event_res[MAX_RUN][MAX_COUNTERS][3]; static u64 event_scaled[MAX_RUN][MAX_COUNTERS]; struct stats { double sum; double sum_sq; }; static double avg_stats(struct stats *stats) { return stats->sum / run_count; } /* * stddev = sqrt(1/N (\Sum n_i^2) - avg(n)^2) */ static double stddev_stats(struct stats *stats) { double avg = stats->sum / run_count; return sqrt(stats->sum_sq/run_count - avg*avg); } struct stats event_res_stats[MAX_COUNTERS][3]; struct stats event_scaled_stats[MAX_COUNTERS]; struct stats runtime_nsecs_stats; struct stats walltime_nsecs_stats; struct stats runtime_cycles_stats; #define MATCH_EVENT(t, c, counter) \ (attrs[counter].type == PERF_TYPE_##t && \ attrs[counter].config == PERF_COUNT_##c) #define ERR_PERF_OPEN \ "Error: counter %d, sys_perf_counter_open() syscall returned with %d (%s)\n" static void create_perf_stat_counter(int counter, int pid) { struct perf_counter_attr *attr = attrs + counter; if (scale) attr->read_format = PERF_FORMAT_TOTAL_TIME_ENABLED | PERF_FORMAT_TOTAL_TIME_RUNNING; if (system_wide) { unsigned int cpu; for (cpu = 0; cpu < nr_cpus; cpu++) { fd[cpu][counter] = sys_perf_counter_open(attr, -1, cpu, -1, 0); if (fd[cpu][counter] < 0 && verbose) fprintf(stderr, ERR_PERF_OPEN, counter, fd[cpu][counter], strerror(errno)); } } else { attr->inherit = inherit; attr->disabled = 1; attr->enable_on_exec = 1; fd[0][counter] = sys_perf_counter_open(attr, pid, -1, -1, 0); if (fd[0][counter] < 0 && verbose) fprintf(stderr, ERR_PERF_OPEN, counter, fd[0][counter], strerror(errno)); } } /* * Does the counter have nsecs as a unit? */ static inline int nsec_counter(int counter) { if (MATCH_EVENT(SOFTWARE, SW_CPU_CLOCK, counter) || MATCH_EVENT(SOFTWARE, SW_TASK_CLOCK, counter)) return 1; return 0; } /* * Read out the results of a single counter: */ static void read_counter(int counter) { u64 *count, single_count[3]; unsigned int cpu; size_t res, nv; int scaled; count = event_res[run_idx][counter]; count[0] = count[1] = count[2] = 0; nv = scale ? 3 : 1; for (cpu = 0; cpu < nr_cpus; cpu++) { if (fd[cpu][counter] < 0) continue; res = read(fd[cpu][counter], single_count, nv * sizeof(u64)); assert(res == nv * sizeof(u64)); close(fd[cpu][counter]); fd[cpu][counter] = -1; count[0] += single_count[0]; if (scale) { count[1] += single_count[1]; count[2] += single_count[2]; } } scaled = 0; if (scale) { if (count[2] == 0) { event_scaled[run_idx][counter] = -1; count[0] = 0; return; } if (count[2] < count[1]) { event_scaled[run_idx][counter] = 1; count[0] = (unsigned long long) ((double)count[0] * count[1] / count[2] + 0.5); } } /* * Save the full runtime - to allow normalization during printout: */ if (MATCH_EVENT(SOFTWARE, SW_TASK_CLOCK, counter)) runtime_nsecs[run_idx] = count[0]; if (MATCH_EVENT(HARDWARE, HW_CPU_CYCLES, counter)) runtime_cycles[run_idx] = count[0]; } static int run_perf_stat(int argc __used, const char **argv) { unsigned long long t0, t1; int status = 0; int counter; int pid; int child_ready_pipe[2], go_pipe[2]; char buf; if (!system_wide) nr_cpus = 1; if (pipe(child_ready_pipe) < 0 || pipe(go_pipe) < 0) { perror("failed to create pipes"); exit(1); } if ((pid = fork()) < 0) perror("failed to fork"); if (!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); } /* * 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]); for (counter = 0; counter < nr_counters; counter++) create_perf_stat_counter(counter, pid); /* * Enable counters and exec the command: */ t0 = rdclock(); close(go_pipe[1]); wait(&status); t1 = rdclock(); walltime_nsecs[run_idx] = t1 - t0; for (counter = 0; counter < nr_counters; counter++) read_counter(counter); return WEXITSTATUS(status); } static void print_noise(double avg, double stddev) { if (run_count > 1) fprintf(stderr, " ( +- %7.3f%% )", 100*stddev / avg); } static void nsec_printout(int counter, double avg, double stddev) { double msecs = avg / 1e6; fprintf(stderr, " %14.6f %-24s", msecs, event_name(counter)); if (MATCH_EVENT(SOFTWARE, SW_TASK_CLOCK, counter)) { fprintf(stderr, " # %10.3f CPUs ", avg / avg_stats(&walltime_nsecs_stats)); } print_noise(avg, stddev); } static void abs_printout(int counter, double avg, double stddev) { fprintf(stderr, " %14.0f %-24s", avg, event_name(counter)); if (MATCH_EVENT(HARDWARE, HW_INSTRUCTIONS, counter)) { fprintf(stderr, " # %10.3f IPC ", avg / avg_stats(&runtime_cycles_stats)); } else { fprintf(stderr, " # %10.3f M/sec", 1000.0 * avg / avg_stats(&runtime_nsecs_stats)); } print_noise(avg, stddev); } /* * Print out the results of a single counter: */ static void print_counter(int counter) { double avg, stddev; int scaled; avg = avg_stats(&event_res_stats[counter][0]); stddev = stddev_stats(&event_res_stats[counter][0]); scaled = avg_stats(&event_scaled_stats[counter]); if (scaled == -1) { fprintf(stderr, " %14s %-24s\n", "", event_name(counter)); return; } if (nsec_counter(counter)) nsec_printout(counter, avg, stddev); else abs_printout(counter, avg, stddev); if (scaled) { double avg_enabled, avg_running; avg_enabled = avg_stats(&event_res_stats[counter][1]); avg_running = avg_stats(&event_res_stats[counter][2]); fprintf(stderr, " (scaled from %.2f%%)", 100 * avg_running / avg_enabled); } fprintf(stderr, "\n"); } static void update_stats(const char *name, int idx, struct stats *stats, u64 *val) { double sq = *val; stats->sum += *val; stats->sum_sq += sq * sq; if (verbose > 1) fprintf(stderr, "debug: %20s[%d]: %Ld\n", name, idx, *val); } /* * Calculate the averages and noises: */ static void calc_avg(void) { int i, j; if (verbose > 1) fprintf(stderr, "\n"); for (i = 0; i < run_count; i++) { update_stats("runtime", 0, &runtime_nsecs_stats, runtime_nsecs + i); update_stats("walltime", 0, &walltime_nsecs_stats, walltime_nsecs + i); update_stats("runtime_cycles", 0, &runtime_cycles_stats, runtime_cycles + i); for (j = 0; j < nr_counters; j++) { update_stats("counter/0", j, event_res_stats[j]+0, event_res[i][j]+0); update_stats("counter/1", j, event_res_stats[j]+1, event_res[i][j]+1); update_stats("counter/2", j, event_res_stats[j]+2, event_res[i][j]+2); if (event_scaled[i][j] != (u64)-1) update_stats("scaled", j, event_scaled_stats + j, event_scaled[i]+j); } } } static void print_stat(int argc, const char **argv) { int i, counter; calc_avg(); fflush(stdout); fprintf(stderr, "\n"); fprintf(stderr, " Performance counter stats for \'%s", argv[0]); for (i = 1; i < argc; i++) fprintf(stderr, " %s", argv[i]); fprintf(stderr, "\'"); if (run_count > 1) fprintf(stderr, " (%d runs)", run_count); fprintf(stderr, ":\n\n"); for (counter = 0; counter < nr_counters; counter++) print_counter(counter); fprintf(stderr, "\n"); fprintf(stderr, " %14.9f 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) { signr = signo; } static void sig_atexit(void) { if (signr == -1) return; signal(signr, SIG_DFL); kill(getpid(), signr); } static const char * const stat_usage[] = { "perf stat [] ", NULL }; static const struct option options[] = { OPT_CALLBACK('e', "event", NULL, "event", "event selector. use 'perf list' to list available events", parse_events), OPT_BOOLEAN('i', "inherit", &inherit, "child tasks inherit counters"), OPT_INTEGER('p', "pid", &target_pid, "stat events on existing pid"), OPT_BOOLEAN('a', "all-cpus", &system_wide, "system-wide collection from all CPUs"), OPT_BOOLEAN('c', "scale", &scale, "scale/normalize counters"), OPT_BOOLEAN('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_END() }; int cmd_stat(int argc, const char **argv, const char *prefix __used) { int status; argc = parse_options(argc, argv, options, stat_usage, PARSE_OPT_STOP_AT_NON_OPTION); if (!argc) usage_with_options(stat_usage, options); if (run_count <= 0 || run_count > MAX_RUN) usage_with_options(stat_usage, options); /* Set attrs and nr_counters if no event is selected and !null_run */ if (!null_run && !nr_counters) { memcpy(attrs, default_attrs, sizeof(default_attrs)); nr_counters = ARRAY_SIZE(default_attrs); } nr_cpus = sysconf(_SC_NPROCESSORS_ONLN); assert(nr_cpus <= MAX_NR_CPUS); assert((int)nr_cpus >= 0); /* * 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); } print_stat(argc, argv); return status; }