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Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs...
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / tools / perf / builtin-stat.c
blob95db31cff6fdbb63e714dc0725998d7ef76103ea
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
53 static 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
69 static int system_wide = 0;
70 static unsigned int nr_cpus = 0;
71 static int run_idx = 0;
72
73 static int run_count = 1;
74 static int inherit = 1;
75 static int scale = 1;
76 static pid_t target_pid = -1;
77 static pid_t child_pid = -1;
78 static int null_run = 0;
79
80 static int fd[MAX_NR_CPUS][MAX_COUNTERS];
81
82 static int event_scaled[MAX_COUNTERS];
83
84 static volatile int done = 0;
85
86 struct stats
87 {
88 double n, mean, M2;
89 };
90
91 static 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
101 static 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 */
122 static 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
130 struct stats event_res_stats[MAX_COUNTERS][3];
131 struct stats runtime_nsecs_stats;
132 struct stats walltime_nsecs_stats;
133 struct stats runtime_cycles_stats;
134 struct 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
143 static 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 */
175 static 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 */
187 static 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
249 static 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
337 static 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
346 static 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
358 static 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 */
393 static 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
424 static 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
458 static volatile int signr = -1;
459
460 static void skip_signal(int signo)
461 {
462 if(target_pid != -1)
463 done = 1;
464
465 signr = signo;
466 }
467
468 static 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
480 static const char * const stat_usage[] = {
481 "perf stat [<options>] [<command>]",
482 NULL
483 };
484
485 static 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
506 int 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 }
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