Root/tools/perf/builtin-stat.c

1/*
2 * builtin-stat.c
3 *
4 * Builtin stat command: Give a precise performance counters summary
5 * overview about any workload, CPU or specific PID.
6 *
7 * Sample output:
8
9   $ perf stat ~/hackbench 10
10   Time: 0.104
11
12    Performance counter stats for '/home/mingo/hackbench':
13
14       1255.538611 task clock ticks # 10.143 CPU utilization factor
15             54011 context switches # 0.043 M/sec
16               385 CPU migrations # 0.000 M/sec
17             17755 pagefaults # 0.014 M/sec
18        3808323185 CPU cycles # 3033.219 M/sec
19        1575111190 instructions # 1254.530 M/sec
20          17367895 cache references # 13.833 M/sec
21           7674421 cache misses # 6.112 M/sec
22
23    Wall-clock time elapsed: 123.786620 msecs
24
25 *
26 * Copyright (C) 2008, Red Hat Inc, Ingo Molnar <mingo@redhat.com>
27 *
28 * Improvements and fixes by:
29 *
30 * Arjan van de Ven <arjan@linux.intel.com>
31 * Yanmin Zhang <yanmin.zhang@intel.com>
32 * Wu Fengguang <fengguang.wu@intel.com>
33 * Mike Galbraith <efault@gmx.de>
34 * Paul Mackerras <paulus@samba.org>
35 * Jaswinder Singh Rajput <jaswinder@kernel.org>
36 *
37 * Released under the GPL v2. (and only v2, not any later version)
38 */
39
40#include "perf.h"
41#include "builtin.h"
42#include "util/util.h"
43#include "util/parse-options.h"
44#include "util/parse-events.h"
45#include "util/event.h"
46#include "util/debug.h"
47#include "util/header.h"
48#include "util/cpumap.h"
49
50#include <sys/prctl.h>
51#include <math.h>
52
53static struct perf_event_attr default_attrs[] = {
54
55  { .type = PERF_TYPE_SOFTWARE, .config = PERF_COUNT_SW_TASK_CLOCK },
56  { .type = PERF_TYPE_SOFTWARE, .config = PERF_COUNT_SW_CONTEXT_SWITCHES },
57  { .type = PERF_TYPE_SOFTWARE, .config = PERF_COUNT_SW_CPU_MIGRATIONS },
58  { .type = PERF_TYPE_SOFTWARE, .config = PERF_COUNT_SW_PAGE_FAULTS },
59
60  { .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_CPU_CYCLES },
61  { .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_INSTRUCTIONS },
62  { .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_BRANCH_INSTRUCTIONS },
63  { .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_BRANCH_MISSES },
64  { .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_CACHE_REFERENCES },
65  { .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_CACHE_MISSES },
66
67};
68
69static int system_wide = 0;
70static unsigned int nr_cpus = 0;
71static int run_idx = 0;
72
73static int run_count = 1;
74static int inherit = 1;
75static int scale = 1;
76static pid_t target_pid = -1;
77static pid_t child_pid = -1;
78static int null_run = 0;
79
80static int fd[MAX_NR_CPUS][MAX_COUNTERS];
81
82static int event_scaled[MAX_COUNTERS];
83
84static volatile int done = 0;
85
86struct stats
87{
88    double n, mean, M2;
89};
90
91static void update_stats(struct stats *stats, u64 val)
92{
93    double delta;
94
95    stats->n++;
96    delta = val - stats->mean;
97    stats->mean += delta / stats->n;
98    stats->M2 += delta*(val - stats->mean);
99}
100
101static double avg_stats(struct stats *stats)
102{
103    return stats->mean;
104}
105
106/*
107 * http://en.wikipedia.org/wiki/Algorithms_for_calculating_variance
108 *
109 * (\Sum n_i^2) - ((\Sum n_i)^2)/n
110 * s^2 = -------------------------------
111 * n - 1
112 *
113 * http://en.wikipedia.org/wiki/Stddev
114 *
115 * The std dev of the mean is related to the std dev by:
116 *
117 * s
118 * s_mean = -------
119 * sqrt(n)
120 *
121 */
122static double stddev_stats(struct stats *stats)
123{
124    double variance = stats->M2 / (stats->n - 1);
125    double variance_mean = variance / stats->n;
126
127    return sqrt(variance_mean);
128}
129
130struct stats event_res_stats[MAX_COUNTERS][3];
131struct stats runtime_nsecs_stats;
132struct stats walltime_nsecs_stats;
133struct stats runtime_cycles_stats;
134struct stats runtime_branches_stats;
135
136#define MATCH_EVENT(t, c, counter) \
137    (attrs[counter].type == PERF_TYPE_##t && \
138     attrs[counter].config == PERF_COUNT_##c)
139
140#define ERR_PERF_OPEN \
141"Error: counter %d, sys_perf_event_open() syscall returned with %d (%s)\n"
142
143static void create_perf_stat_counter(int counter, int pid)
144{
145    struct perf_event_attr *attr = attrs + counter;
146
147    if (scale)
148        attr->read_format = PERF_FORMAT_TOTAL_TIME_ENABLED |
149                    PERF_FORMAT_TOTAL_TIME_RUNNING;
150
151    if (system_wide) {
152        unsigned int cpu;
153
154        for (cpu = 0; cpu < nr_cpus; cpu++) {
155            fd[cpu][counter] = sys_perf_event_open(attr, -1, cpumap[cpu], -1, 0);
156            if (fd[cpu][counter] < 0 && verbose)
157                fprintf(stderr, ERR_PERF_OPEN, counter,
158                    fd[cpu][counter], strerror(errno));
159        }
160    } else {
161        attr->inherit = inherit;
162        attr->disabled = 1;
163        attr->enable_on_exec = 1;
164
165        fd[0][counter] = sys_perf_event_open(attr, pid, -1, -1, 0);
166        if (fd[0][counter] < 0 && verbose)
167            fprintf(stderr, ERR_PERF_OPEN, counter,
168                fd[0][counter], strerror(errno));
169    }
170}
171
172/*
173 * Does the counter have nsecs as a unit?
174 */
175static inline int nsec_counter(int counter)
176{
177    if (MATCH_EVENT(SOFTWARE, SW_CPU_CLOCK, counter) ||
178        MATCH_EVENT(SOFTWARE, SW_TASK_CLOCK, counter))
179        return 1;
180
181    return 0;
182}
183
184/*
185 * Read out the results of a single counter:
186 */
187static void read_counter(int counter)
188{
189    u64 count[3], single_count[3];
190    unsigned int cpu;
191    size_t res, nv;
192    int scaled;
193    int i;
194
195    count[0] = count[1] = count[2] = 0;
196
197    nv = scale ? 3 : 1;
198    for (cpu = 0; cpu < nr_cpus; cpu++) {
199        if (fd[cpu][counter] < 0)
200            continue;
201
202        res = read(fd[cpu][counter], single_count, nv * sizeof(u64));
203        assert(res == nv * sizeof(u64));
204
205        close(fd[cpu][counter]);
206        fd[cpu][counter] = -1;
207
208        count[0] += single_count[0];
209        if (scale) {
210            count[1] += single_count[1];
211            count[2] += single_count[2];
212        }
213    }
214
215    scaled = 0;
216    if (scale) {
217        if (count[2] == 0) {
218            event_scaled[counter] = -1;
219            count[0] = 0;
220            return;
221        }
222
223        if (count[2] < count[1]) {
224            event_scaled[counter] = 1;
225            count[0] = (unsigned long long)
226                ((double)count[0] * count[1] / count[2] + 0.5);
227        }
228    }
229
230    for (i = 0; i < 3; i++)
231        update_stats(&event_res_stats[counter][i], count[i]);
232
233    if (verbose) {
234        fprintf(stderr, "%s: %Ld %Ld %Ld\n", event_name(counter),
235                count[0], count[1], count[2]);
236    }
237
238    /*
239     * Save the full runtime - to allow normalization during printout:
240     */
241    if (MATCH_EVENT(SOFTWARE, SW_TASK_CLOCK, counter))
242        update_stats(&runtime_nsecs_stats, count[0]);
243    if (MATCH_EVENT(HARDWARE, HW_CPU_CYCLES, counter))
244        update_stats(&runtime_cycles_stats, count[0]);
245    if (MATCH_EVENT(HARDWARE, HW_BRANCH_INSTRUCTIONS, counter))
246        update_stats(&runtime_branches_stats, count[0]);
247}
248
249static int run_perf_stat(int argc __used, const char **argv)
250{
251    unsigned long long t0, t1;
252    int status = 0;
253    int counter;
254    int pid = target_pid;
255    int child_ready_pipe[2], go_pipe[2];
256    const bool forks = (target_pid == -1 && argc > 0);
257    char buf;
258
259    if (!system_wide)
260        nr_cpus = 1;
261
262    if (forks && (pipe(child_ready_pipe) < 0 || pipe(go_pipe) < 0)) {
263        perror("failed to create pipes");
264        exit(1);
265    }
266
267    if (forks) {
268        if ((pid = fork()) < 0)
269            perror("failed to fork");
270
271        if (!pid) {
272            close(child_ready_pipe[0]);
273            close(go_pipe[1]);
274            fcntl(go_pipe[0], F_SETFD, FD_CLOEXEC);
275
276            /*
277             * Do a dummy execvp to get the PLT entry resolved,
278             * so we avoid the resolver overhead on the real
279             * execvp call.
280             */
281            execvp("", (char **)argv);
282
283            /*
284             * Tell the parent we're ready to go
285             */
286            close(child_ready_pipe[1]);
287
288            /*
289             * Wait until the parent tells us to go.
290             */
291            if (read(go_pipe[0], &buf, 1) == -1)
292                perror("unable to read pipe");
293
294            execvp(argv[0], (char **)argv);
295
296            perror(argv[0]);
297            exit(-1);
298        }
299
300        child_pid = pid;
301
302        /*
303         * Wait for the child to be ready to exec.
304         */
305        close(child_ready_pipe[1]);
306        close(go_pipe[0]);
307        if (read(child_ready_pipe[0], &buf, 1) == -1)
308            perror("unable to read pipe");
309        close(child_ready_pipe[0]);
310    }
311
312    for (counter = 0; counter < nr_counters; counter++)
313        create_perf_stat_counter(counter, pid);
314
315    /*
316     * Enable counters and exec the command:
317     */
318    t0 = rdclock();
319
320    if (forks) {
321        close(go_pipe[1]);
322        wait(&status);
323    } else {
324        while(!done);
325    }
326
327    t1 = rdclock();
328
329    update_stats(&walltime_nsecs_stats, t1 - t0);
330
331    for (counter = 0; counter < nr_counters; counter++)
332        read_counter(counter);
333
334    return WEXITSTATUS(status);
335}
336
337static void print_noise(int counter, double avg)
338{
339    if (run_count == 1)
340        return;
341
342    fprintf(stderr, " ( +- %7.3f%% )",
343            100 * stddev_stats(&event_res_stats[counter][0]) / avg);
344}
345
346static void nsec_printout(int counter, double avg)
347{
348    double msecs = avg / 1e6;
349
350    fprintf(stderr, " %14.6f %-24s", msecs, event_name(counter));
351
352    if (MATCH_EVENT(SOFTWARE, SW_TASK_CLOCK, counter)) {
353        fprintf(stderr, " # %10.3f CPUs ",
354                avg / avg_stats(&walltime_nsecs_stats));
355    }
356}
357
358static void abs_printout(int counter, double avg)
359{
360    double total, ratio = 0.0;
361
362    fprintf(stderr, " %14.0f %-24s", avg, event_name(counter));
363
364    if (MATCH_EVENT(HARDWARE, HW_INSTRUCTIONS, counter)) {
365        total = avg_stats(&runtime_cycles_stats);
366
367        if (total)
368            ratio = avg / total;
369
370        fprintf(stderr, " # %10.3f IPC ", ratio);
371    } else if (MATCH_EVENT(HARDWARE, HW_BRANCH_MISSES, counter) &&
372            runtime_branches_stats.n != 0) {
373        total = avg_stats(&runtime_branches_stats);
374
375        if (total)
376            ratio = avg * 100 / total;
377
378        fprintf(stderr, " # %10.3f %% ", ratio);
379
380    } else if (runtime_nsecs_stats.n != 0) {
381        total = avg_stats(&runtime_nsecs_stats);
382
383        if (total)
384            ratio = 1000.0 * avg / total;
385
386        fprintf(stderr, " # %10.3f M/sec", ratio);
387    }
388}
389
390/*
391 * Print out the results of a single counter:
392 */
393static void print_counter(int counter)
394{
395    double avg = avg_stats(&event_res_stats[counter][0]);
396    int scaled = event_scaled[counter];
397
398    if (scaled == -1) {
399        fprintf(stderr, " %14s %-24s\n",
400            "<not counted>", event_name(counter));
401        return;
402    }
403
404    if (nsec_counter(counter))
405        nsec_printout(counter, avg);
406    else
407        abs_printout(counter, avg);
408
409    print_noise(counter, avg);
410
411    if (scaled) {
412        double avg_enabled, avg_running;
413
414        avg_enabled = avg_stats(&event_res_stats[counter][1]);
415        avg_running = avg_stats(&event_res_stats[counter][2]);
416
417        fprintf(stderr, " (scaled from %.2f%%)",
418                100 * avg_running / avg_enabled);
419    }
420
421    fprintf(stderr, "\n");
422}
423
424static void print_stat(int argc, const char **argv)
425{
426    int i, counter;
427
428    fflush(stdout);
429
430    fprintf(stderr, "\n");
431    fprintf(stderr, " Performance counter stats for ");
432    if(target_pid == -1) {
433        fprintf(stderr, "\'%s", argv[0]);
434        for (i = 1; i < argc; i++)
435            fprintf(stderr, " %s", argv[i]);
436    }else
437        fprintf(stderr, "task pid \'%d", target_pid);
438
439    fprintf(stderr, "\'");
440    if (run_count > 1)
441        fprintf(stderr, " (%d runs)", run_count);
442    fprintf(stderr, ":\n\n");
443
444    for (counter = 0; counter < nr_counters; counter++)
445        print_counter(counter);
446
447    fprintf(stderr, "\n");
448    fprintf(stderr, " %14.9f seconds time elapsed",
449            avg_stats(&walltime_nsecs_stats)/1e9);
450    if (run_count > 1) {
451        fprintf(stderr, " ( +- %7.3f%% )",
452                100*stddev_stats(&walltime_nsecs_stats) /
453                avg_stats(&walltime_nsecs_stats));
454    }
455    fprintf(stderr, "\n\n");
456}
457
458static volatile int signr = -1;
459
460static void skip_signal(int signo)
461{
462    if(target_pid != -1)
463        done = 1;
464
465    signr = signo;
466}
467
468static void sig_atexit(void)
469{
470    if (child_pid != -1)
471        kill(child_pid, SIGTERM);
472
473    if (signr == -1)
474        return;
475
476    signal(signr, SIG_DFL);
477    kill(getpid(), signr);
478}
479
480static const char * const stat_usage[] = {
481    "perf stat [<options>] [<command>]",
482    NULL
483};
484
485static const struct option options[] = {
486    OPT_CALLBACK('e', "event", NULL, "event",
487             "event selector. use 'perf list' to list available events",
488             parse_events),
489    OPT_BOOLEAN('i', "inherit", &inherit,
490            "child tasks inherit counters"),
491    OPT_INTEGER('p', "pid", &target_pid,
492            "stat events on existing pid"),
493    OPT_BOOLEAN('a', "all-cpus", &system_wide,
494            "system-wide collection from all CPUs"),
495    OPT_BOOLEAN('c', "scale", &scale,
496            "scale/normalize counters"),
497    OPT_BOOLEAN('v', "verbose", &verbose,
498            "be more verbose (show counter open errors, etc)"),
499    OPT_INTEGER('r', "repeat", &run_count,
500            "repeat command and print average + stddev (max: 100)"),
501    OPT_BOOLEAN('n', "null", &null_run,
502            "null run - dont start any counters"),
503    OPT_END()
504};
505
506int cmd_stat(int argc, const char **argv, const char *prefix __used)
507{
508    int status;
509
510    argc = parse_options(argc, argv, options, stat_usage,
511        PARSE_OPT_STOP_AT_NON_OPTION);
512    if (!argc && target_pid == -1)
513        usage_with_options(stat_usage, options);
514    if (run_count <= 0)
515        usage_with_options(stat_usage, options);
516
517    /* Set attrs and nr_counters if no event is selected and !null_run */
518    if (!null_run && !nr_counters) {
519        memcpy(attrs, default_attrs, sizeof(default_attrs));
520        nr_counters = ARRAY_SIZE(default_attrs);
521    }
522
523    if (system_wide)
524        nr_cpus = read_cpu_map();
525    else
526        nr_cpus = 1;
527
528    /*
529     * We dont want to block the signals - that would cause
530     * child tasks to inherit that and Ctrl-C would not work.
531     * What we want is for Ctrl-C to work in the exec()-ed
532     * task, but being ignored by perf stat itself:
533     */
534    atexit(sig_atexit);
535    signal(SIGINT, skip_signal);
536    signal(SIGALRM, skip_signal);
537    signal(SIGABRT, skip_signal);
538
539    status = 0;
540    for (run_idx = 0; run_idx < run_count; run_idx++) {
541        if (run_count != 1 && verbose)
542            fprintf(stderr, "[ perf stat: executing run #%d ... ]\n", run_idx + 1);
543        status = run_perf_stat(argc, argv);
544    }
545
546    print_stat(argc, argv);
547
548    return status;
549}
550

Archive Download this file

Branches:
ben-wpan
ben-wpan-stefan
javiroman/ks7010
jz-2.6.34
jz-2.6.34-rc5
jz-2.6.34-rc6
jz-2.6.34-rc7
jz-2.6.35
jz-2.6.36
jz-2.6.37
jz-2.6.38
jz-2.6.39
jz-3.0
jz-3.1
jz-3.11
jz-3.12
jz-3.13
jz-3.15
jz-3.16
jz-3.18-dt
jz-3.2
jz-3.3
jz-3.4
jz-3.5
jz-3.6
jz-3.6-rc2-pwm
jz-3.9
jz-3.9-clk
jz-3.9-rc8
jz47xx
jz47xx-2.6.38
master

Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9



interactive