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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
48#include <sys/prctl.h>
49#include <math.h>
50
51static struct perf_event_attr default_attrs[] = {
52
53 { .type = PERF_TYPE_SOFTWARE, .config = PERF_COUNT_SW_TASK_CLOCK },
54 { .type = PERF_TYPE_SOFTWARE, .config = PERF_COUNT_SW_CONTEXT_SWITCHES},
55 { .type = PERF_TYPE_SOFTWARE, .config = PERF_COUNT_SW_CPU_MIGRATIONS },
56 { .type = PERF_TYPE_SOFTWARE, .config = PERF_COUNT_SW_PAGE_FAULTS },
57
58 { .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_CPU_CYCLES },
59 { .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_INSTRUCTIONS },
60 { .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_CACHE_REFERENCES},
61 { .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_CACHE_MISSES },
62
63};
64
65static int system_wide = 0;
66static unsigned int nr_cpus = 0;
67static int run_idx = 0;
68
69static int run_count = 1;
70static int inherit = 1;
71static int scale = 1;
72static pid_t target_pid = -1;
73static pid_t child_pid = -1;
74static int null_run = 0;
75
76static int fd[MAX_NR_CPUS][MAX_COUNTERS];
77
78static int event_scaled[MAX_COUNTERS];
79
80struct stats
81{
82 double n, mean, M2;
83};
84
85static void update_stats(struct stats *stats, u64 val)
86{
87 double delta;
88
89 stats->n++;
90 delta = val - stats->mean;
91 stats->mean += delta / stats->n;
92 stats->M2 += delta*(val - stats->mean);
93}
94
95static double avg_stats(struct stats *stats)
96{
97 return stats->mean;
98}
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116static double stddev_stats(struct stats *stats)
117{
118 double variance = stats->M2 / (stats->n - 1);
119 double variance_mean = variance / stats->n;
120
121 return sqrt(variance_mean);
122}
123
124struct stats event_res_stats[MAX_COUNTERS][3];
125struct stats runtime_nsecs_stats;
126struct stats walltime_nsecs_stats;
127struct stats runtime_cycles_stats;
128
129#define MATCH_EVENT(t, c, counter) \
130 (attrs[counter].type == PERF_TYPE_##t && \
131 attrs[counter].config == PERF_COUNT_##c)
132
133#define ERR_PERF_OPEN \
134"Error: counter %d, sys_perf_event_open() syscall returned with %d (%s)\n"
135
136static void create_perf_stat_counter(int counter, int pid)
137{
138 struct perf_event_attr *attr = attrs + counter;
139
140 if (scale)
141 attr->read_format = PERF_FORMAT_TOTAL_TIME_ENABLED |
142 PERF_FORMAT_TOTAL_TIME_RUNNING;
143
144 if (system_wide) {
145 unsigned int cpu;
146
147 for (cpu = 0; cpu < nr_cpus; cpu++) {
148 fd[cpu][counter] = sys_perf_event_open(attr, -1, cpu, -1, 0);
149 if (fd[cpu][counter] < 0 && verbose)
150 fprintf(stderr, ERR_PERF_OPEN, counter,
151 fd[cpu][counter], strerror(errno));
152 }
153 } else {
154 attr->inherit = inherit;
155 attr->disabled = 1;
156 attr->enable_on_exec = 1;
157
158 fd[0][counter] = sys_perf_event_open(attr, pid, -1, -1, 0);
159 if (fd[0][counter] < 0 && verbose)
160 fprintf(stderr, ERR_PERF_OPEN, counter,
161 fd[0][counter], strerror(errno));
162 }
163}
164
165
166
167
168static inline int nsec_counter(int counter)
169{
170 if (MATCH_EVENT(SOFTWARE, SW_CPU_CLOCK, counter) ||
171 MATCH_EVENT(SOFTWARE, SW_TASK_CLOCK, counter))
172 return 1;
173
174 return 0;
175}
176
177
178
179
180static void read_counter(int counter)
181{
182 u64 count[3], single_count[3];
183 unsigned int cpu;
184 size_t res, nv;
185 int scaled;
186 int i;
187
188 count[0] = count[1] = count[2] = 0;
189
190 nv = scale ? 3 : 1;
191 for (cpu = 0; cpu < nr_cpus; cpu++) {
192 if (fd[cpu][counter] < 0)
193 continue;
194
195 res = read(fd[cpu][counter], single_count, nv * sizeof(u64));
196 assert(res == nv * sizeof(u64));
197
198 close(fd[cpu][counter]);
199 fd[cpu][counter] = -1;
200
201 count[0] += single_count[0];
202 if (scale) {
203 count[1] += single_count[1];
204 count[2] += single_count[2];
205 }
206 }
207
208 scaled = 0;
209 if (scale) {
210 if (count[2] == 0) {
211 event_scaled[counter] = -1;
212 count[0] = 0;
213 return;
214 }
215
216 if (count[2] < count[1]) {
217 event_scaled[counter] = 1;
218 count[0] = (unsigned long long)
219 ((double)count[0] * count[1] / count[2] + 0.5);
220 }
221 }
222
223 for (i = 0; i < 3; i++)
224 update_stats(&event_res_stats[counter][i], count[i]);
225
226 if (verbose) {
227 fprintf(stderr, "%s: %Ld %Ld %Ld\n", event_name(counter),
228 count[0], count[1], count[2]);
229 }
230
231
232
233
234 if (MATCH_EVENT(SOFTWARE, SW_TASK_CLOCK, counter))
235 update_stats(&runtime_nsecs_stats, count[0]);
236 if (MATCH_EVENT(HARDWARE, HW_CPU_CYCLES, counter))
237 update_stats(&runtime_cycles_stats, count[0]);
238}
239
240static int run_perf_stat(int argc __used, const char **argv)
241{
242 unsigned long long t0, t1;
243 int status = 0;
244 int counter;
245 int pid;
246 int child_ready_pipe[2], go_pipe[2];
247 char buf;
248
249 if (!system_wide)
250 nr_cpus = 1;
251
252 if (pipe(child_ready_pipe) < 0 || pipe(go_pipe) < 0) {
253 perror("failed to create pipes");
254 exit(1);
255 }
256
257 if ((pid = fork()) < 0)
258 perror("failed to fork");
259
260 if (!pid) {
261 close(child_ready_pipe[0]);
262 close(go_pipe[1]);
263 fcntl(go_pipe[0], F_SETFD, FD_CLOEXEC);
264
265
266
267
268
269
270 execvp("", (char **)argv);
271
272
273
274
275 close(child_ready_pipe[1]);
276
277
278
279
280 if (read(go_pipe[0], &buf, 1) == -1)
281 perror("unable to read pipe");
282
283 execvp(argv[0], (char **)argv);
284
285 perror(argv[0]);
286 exit(-1);
287 }
288
289 child_pid = pid;
290
291
292
293
294 close(child_ready_pipe[1]);
295 close(go_pipe[0]);
296 if (read(child_ready_pipe[0], &buf, 1) == -1)
297 perror("unable to read pipe");
298 close(child_ready_pipe[0]);
299
300 for (counter = 0; counter < nr_counters; counter++)
301 create_perf_stat_counter(counter, pid);
302
303
304
305
306 t0 = rdclock();
307
308 close(go_pipe[1]);
309 wait(&status);
310
311 t1 = rdclock();
312
313 update_stats(&walltime_nsecs_stats, t1 - t0);
314
315 for (counter = 0; counter < nr_counters; counter++)
316 read_counter(counter);
317
318 return WEXITSTATUS(status);
319}
320
321static void print_noise(int counter, double avg)
322{
323 if (run_count == 1)
324 return;
325
326 fprintf(stderr, " ( +- %7.3f%% )",
327 100 * stddev_stats(&event_res_stats[counter][0]) / avg);
328}
329
330static void nsec_printout(int counter, double avg)
331{
332 double msecs = avg / 1e6;
333
334 fprintf(stderr, " %14.6f %-24s", msecs, event_name(counter));
335
336 if (MATCH_EVENT(SOFTWARE, SW_TASK_CLOCK, counter)) {
337 fprintf(stderr, " # %10.3f CPUs ",
338 avg / avg_stats(&walltime_nsecs_stats));
339 }
340}
341
342static void abs_printout(int counter, double avg)
343{
344 double total, ratio = 0.0;
345
346 fprintf(stderr, " %14.0f %-24s", avg, event_name(counter));
347
348 if (MATCH_EVENT(HARDWARE, HW_INSTRUCTIONS, counter)) {
349 total = avg_stats(&runtime_cycles_stats);
350
351 if (total)
352 ratio = avg / total;
353
354 fprintf(stderr, " # %10.3f IPC ", ratio);
355 } else {
356 total = avg_stats(&runtime_nsecs_stats);
357
358 if (total)
359 ratio = 1000.0 * avg / total;
360
361 fprintf(stderr, " # %10.3f M/sec", ratio);
362 }
363}
364
365
366
367
368static void print_counter(int counter)
369{
370 double avg = avg_stats(&event_res_stats[counter][0]);
371 int scaled = event_scaled[counter];
372
373 if (scaled == -1) {
374 fprintf(stderr, " %14s %-24s\n",
375 "<not counted>", event_name(counter));
376 return;
377 }
378
379 if (nsec_counter(counter))
380 nsec_printout(counter, avg);
381 else
382 abs_printout(counter, avg);
383
384 print_noise(counter, avg);
385
386 if (scaled) {
387 double avg_enabled, avg_running;
388
389 avg_enabled = avg_stats(&event_res_stats[counter][1]);
390 avg_running = avg_stats(&event_res_stats[counter][2]);
391
392 fprintf(stderr, " (scaled from %.2f%%)",
393 100 * avg_running / avg_enabled);
394 }
395
396 fprintf(stderr, "\n");
397}
398
399static void print_stat(int argc, const char **argv)
400{
401 int i, counter;
402
403 fflush(stdout);
404
405 fprintf(stderr, "\n");
406 fprintf(stderr, " Performance counter stats for \'%s", argv[0]);
407
408 for (i = 1; i < argc; i++)
409 fprintf(stderr, " %s", argv[i]);
410
411 fprintf(stderr, "\'");
412 if (run_count > 1)
413 fprintf(stderr, " (%d runs)", run_count);
414 fprintf(stderr, ":\n\n");
415
416 for (counter = 0; counter < nr_counters; counter++)
417 print_counter(counter);
418
419 fprintf(stderr, "\n");
420 fprintf(stderr, " %14.9f seconds time elapsed",
421 avg_stats(&walltime_nsecs_stats)/1e9);
422 if (run_count > 1) {
423 fprintf(stderr, " ( +- %7.3f%% )",
424 100*stddev_stats(&walltime_nsecs_stats) /
425 avg_stats(&walltime_nsecs_stats));
426 }
427 fprintf(stderr, "\n\n");
428}
429
430static volatile int signr = -1;
431
432static void skip_signal(int signo)
433{
434 signr = signo;
435}
436
437static void sig_atexit(void)
438{
439 if (child_pid != -1)
440 kill(child_pid, SIGTERM);
441
442 if (signr == -1)
443 return;
444
445 signal(signr, SIG_DFL);
446 kill(getpid(), signr);
447}
448
449static const char * const stat_usage[] = {
450 "perf stat [<options>] <command>",
451 NULL
452};
453
454static const struct option options[] = {
455 OPT_CALLBACK('e', "event", NULL, "event",
456 "event selector. use 'perf list' to list available events",
457 parse_events),
458 OPT_BOOLEAN('i', "inherit", &inherit,
459 "child tasks inherit counters"),
460 OPT_INTEGER('p', "pid", &target_pid,
461 "stat events on existing pid"),
462 OPT_BOOLEAN('a', "all-cpus", &system_wide,
463 "system-wide collection from all CPUs"),
464 OPT_BOOLEAN('c', "scale", &scale,
465 "scale/normalize counters"),
466 OPT_BOOLEAN('v', "verbose", &verbose,
467 "be more verbose (show counter open errors, etc)"),
468 OPT_INTEGER('r', "repeat", &run_count,
469 "repeat command and print average + stddev (max: 100)"),
470 OPT_BOOLEAN('n', "null", &null_run,
471 "null run - dont start any counters"),
472 OPT_END()
473};
474
475int cmd_stat(int argc, const char **argv, const char *prefix __used)
476{
477 int status;
478
479 argc = parse_options(argc, argv, options, stat_usage,
480 PARSE_OPT_STOP_AT_NON_OPTION);
481 if (!argc)
482 usage_with_options(stat_usage, options);
483 if (run_count <= 0)
484 usage_with_options(stat_usage, options);
485
486
487 if (!null_run && !nr_counters) {
488 memcpy(attrs, default_attrs, sizeof(default_attrs));
489 nr_counters = ARRAY_SIZE(default_attrs);
490 }
491
492 nr_cpus = sysconf(_SC_NPROCESSORS_ONLN);
493 assert(nr_cpus <= MAX_NR_CPUS);
494 assert((int)nr_cpus >= 0);
495
496
497
498
499
500
501
502 atexit(sig_atexit);
503 signal(SIGINT, skip_signal);
504 signal(SIGALRM, skip_signal);
505 signal(SIGABRT, skip_signal);
506
507 status = 0;
508 for (run_idx = 0; run_idx < run_count; run_idx++) {
509 if (run_count != 1 && verbose)
510 fprintf(stderr, "[ perf stat: executing run #%d ... ]\n", run_idx + 1);
511 status = run_perf_stat(argc, argv);
512 }
513
514 print_stat(argc, argv);
515
516 return status;
517}
518
