c373683
[firefly-linux-kernel-4.4.55.git] /
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
48 #include <sys/prctl.h>
49 #include <math.h>
50
51 static 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
65 static int                      system_wide                     =  0;
66 static unsigned int             nr_cpus                         =  0;
67 static int                      run_idx                         =  0;
68
69 static int                      run_count                       =  1;
70 static int                      inherit                         =  1;
71 static int                      scale                           =  1;
72 static pid_t                    target_pid                      = -1;
73 static pid_t                    child_pid                       = -1;
74 static int                      null_run                        =  0;
75
76 static int                      fd[MAX_NR_CPUS][MAX_COUNTERS];
77
78 static int                      event_scaled[MAX_COUNTERS];
79
80 struct stats
81 {
82         double n, mean, M2;
83 };
84
85 static 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
95 static double avg_stats(struct stats *stats)
96 {
97         return stats->mean;
98 }
99
100 /*
101  * http://en.wikipedia.org/wiki/Algorithms_for_calculating_variance
102  *
103  *       (\Sum n_i^2) - ((\Sum n_i)^2)/n
104  * s^2 = -------------------------------
105  *                  n - 1
106  *
107  * http://en.wikipedia.org/wiki/Stddev
108  *
109  * The std dev of the mean is related to the std dev by:
110  *
111  *             s
112  * s_mean = -------
113  *          sqrt(n)
114  *
115  */
116 static 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
124 struct stats                    event_res_stats[MAX_COUNTERS][3];
125 struct stats                    runtime_nsecs_stats;
126 struct stats                    walltime_nsecs_stats;
127 struct stats                    runtime_cycles_stats;
128 struct stats                    runtime_branches_stats;
129
130 #define MATCH_EVENT(t, c, counter)                      \
131         (attrs[counter].type == PERF_TYPE_##t &&        \
132          attrs[counter].config == PERF_COUNT_##c)
133
134 #define ERR_PERF_OPEN \
135 "Error: counter %d, sys_perf_event_open() syscall returned with %d (%s)\n"
136
137 static void create_perf_stat_counter(int counter, int pid)
138 {
139         struct perf_event_attr *attr = attrs + counter;
140
141         if (scale)
142                 attr->read_format = PERF_FORMAT_TOTAL_TIME_ENABLED |
143                                     PERF_FORMAT_TOTAL_TIME_RUNNING;
144
145         if (system_wide) {
146                 unsigned int cpu;
147
148                 for (cpu = 0; cpu < nr_cpus; cpu++) {
149                         fd[cpu][counter] = sys_perf_event_open(attr, -1, cpu, -1, 0);
150                         if (fd[cpu][counter] < 0 && verbose)
151                                 fprintf(stderr, ERR_PERF_OPEN, counter,
152                                         fd[cpu][counter], strerror(errno));
153                 }
154         } else {
155                 attr->inherit        = inherit;
156                 attr->disabled       = 1;
157                 attr->enable_on_exec = 1;
158
159                 fd[0][counter] = sys_perf_event_open(attr, pid, -1, -1, 0);
160                 if (fd[0][counter] < 0 && verbose)
161                         fprintf(stderr, ERR_PERF_OPEN, counter,
162                                 fd[0][counter], strerror(errno));
163         }
164 }
165
166 /*
167  * Does the counter have nsecs as a unit?
168  */
169 static inline int nsec_counter(int counter)
170 {
171         if (MATCH_EVENT(SOFTWARE, SW_CPU_CLOCK, counter) ||
172             MATCH_EVENT(SOFTWARE, SW_TASK_CLOCK, counter))
173                 return 1;
174
175         return 0;
176 }
177
178 /*
179  * Read out the results of a single counter:
180  */
181 static void read_counter(int counter)
182 {
183         u64 count[3], single_count[3];
184         unsigned int cpu;
185         size_t res, nv;
186         int scaled;
187         int i;
188
189         count[0] = count[1] = count[2] = 0;
190
191         nv = scale ? 3 : 1;
192         for (cpu = 0; cpu < nr_cpus; cpu++) {
193                 if (fd[cpu][counter] < 0)
194                         continue;
195
196                 res = read(fd[cpu][counter], single_count, nv * sizeof(u64));
197                 assert(res == nv * sizeof(u64));
198
199                 close(fd[cpu][counter]);
200                 fd[cpu][counter] = -1;
201
202                 count[0] += single_count[0];
203                 if (scale) {
204                         count[1] += single_count[1];
205                         count[2] += single_count[2];
206                 }
207         }
208
209         scaled = 0;
210         if (scale) {
211                 if (count[2] == 0) {
212                         event_scaled[counter] = -1;
213                         count[0] = 0;
214                         return;
215                 }
216
217                 if (count[2] < count[1]) {
218                         event_scaled[counter] = 1;
219                         count[0] = (unsigned long long)
220                                 ((double)count[0] * count[1] / count[2] + 0.5);
221                 }
222         }
223
224         for (i = 0; i < 3; i++)
225                 update_stats(&event_res_stats[counter][i], count[i]);
226
227         if (verbose) {
228                 fprintf(stderr, "%s: %Ld %Ld %Ld\n", event_name(counter),
229                                 count[0], count[1], count[2]);
230         }
231
232         /*
233          * Save the full runtime - to allow normalization during printout:
234          */
235         if (MATCH_EVENT(SOFTWARE, SW_TASK_CLOCK, counter))
236                 update_stats(&runtime_nsecs_stats, count[0]);
237         if (MATCH_EVENT(HARDWARE, HW_CPU_CYCLES, counter))
238                 update_stats(&runtime_cycles_stats, count[0]);
239         if (MATCH_EVENT(HARDWARE, HW_BRANCH_INSTRUCTIONS, counter))
240                 update_stats(&runtime_branches_stats, count[0]);
241 }
242
243 static int run_perf_stat(int argc __used, const char **argv)
244 {
245         unsigned long long t0, t1;
246         int status = 0;
247         int counter;
248         int pid;
249         int child_ready_pipe[2], go_pipe[2];
250         char buf;
251
252         if (!system_wide)
253                 nr_cpus = 1;
254
255         if (pipe(child_ready_pipe) < 0 || pipe(go_pipe) < 0) {
256                 perror("failed to create pipes");
257                 exit(1);
258         }
259
260         if ((pid = fork()) < 0)
261                 perror("failed to fork");
262
263         if (!pid) {
264                 close(child_ready_pipe[0]);
265                 close(go_pipe[1]);
266                 fcntl(go_pipe[0], F_SETFD, FD_CLOEXEC);
267
268                 /*
269                  * Do a dummy execvp to get the PLT entry resolved,
270                  * so we avoid the resolver overhead on the real
271                  * execvp call.
272                  */
273                 execvp("", (char **)argv);
274
275                 /*
276                  * Tell the parent we're ready to go
277                  */
278                 close(child_ready_pipe[1]);
279
280                 /*
281                  * Wait until the parent tells us to go.
282                  */
283                 if (read(go_pipe[0], &buf, 1) == -1)
284                         perror("unable to read pipe");
285
286                 execvp(argv[0], (char **)argv);
287
288                 perror(argv[0]);
289                 exit(-1);
290         }
291
292         child_pid = pid;
293
294         /*
295          * Wait for the child to be ready to exec.
296          */
297         close(child_ready_pipe[1]);
298         close(go_pipe[0]);
299         if (read(child_ready_pipe[0], &buf, 1) == -1)
300                 perror("unable to read pipe");
301         close(child_ready_pipe[0]);
302
303         for (counter = 0; counter < nr_counters; counter++)
304                 create_perf_stat_counter(counter, pid);
305
306         /*
307          * Enable counters and exec the command:
308          */
309         t0 = rdclock();
310
311         close(go_pipe[1]);
312         wait(&status);
313
314         t1 = rdclock();
315
316         update_stats(&walltime_nsecs_stats, t1 - t0);
317
318         for (counter = 0; counter < nr_counters; counter++)
319                 read_counter(counter);
320
321         return WEXITSTATUS(status);
322 }
323
324 static void print_noise(int counter, double avg)
325 {
326         if (run_count == 1)
327                 return;
328
329         fprintf(stderr, "   ( +- %7.3f%% )",
330                         100 * stddev_stats(&event_res_stats[counter][0]) / avg);
331 }
332
333 static void nsec_printout(int counter, double avg)
334 {
335         double msecs = avg / 1e6;
336
337         fprintf(stderr, " %14.6f  %-24s", msecs, event_name(counter));
338
339         if (MATCH_EVENT(SOFTWARE, SW_TASK_CLOCK, counter)) {
340                 fprintf(stderr, " # %10.3f CPUs ",
341                                 avg / avg_stats(&walltime_nsecs_stats));
342         }
343 }
344
345 static void abs_printout(int counter, double avg)
346 {
347         double total, ratio = 0.0;
348
349         fprintf(stderr, " %14.0f  %-24s", avg, event_name(counter));
350
351         if (MATCH_EVENT(HARDWARE, HW_INSTRUCTIONS, counter)) {
352                 total = avg_stats(&runtime_cycles_stats);
353
354                 if (total)
355                         ratio = avg / total;
356
357                 fprintf(stderr, " # %10.3f IPC  ", ratio);
358         } else if (MATCH_EVENT(HARDWARE, HW_BRANCH_MISSES, counter)) {
359                 total = avg_stats(&runtime_branches_stats);
360
361                 if (total)
362                         ratio = avg * 100 / total;
363
364                 fprintf(stderr, " # %10.3f %%  ", ratio);
365
366         } else {
367                 total = avg_stats(&runtime_nsecs_stats);
368
369                 if (total)
370                         ratio = 1000.0 * avg / total;
371
372                 fprintf(stderr, " # %10.3f M/sec", ratio);
373         }
374 }
375
376 /*
377  * Print out the results of a single counter:
378  */
379 static void print_counter(int counter)
380 {
381         double avg = avg_stats(&event_res_stats[counter][0]);
382         int scaled = event_scaled[counter];
383
384         if (scaled == -1) {
385                 fprintf(stderr, " %14s  %-24s\n",
386                         "<not counted>", event_name(counter));
387                 return;
388         }
389
390         if (nsec_counter(counter))
391                 nsec_printout(counter, avg);
392         else
393                 abs_printout(counter, avg);
394
395         print_noise(counter, avg);
396
397         if (scaled) {
398                 double avg_enabled, avg_running;
399
400                 avg_enabled = avg_stats(&event_res_stats[counter][1]);
401                 avg_running = avg_stats(&event_res_stats[counter][2]);
402
403                 fprintf(stderr, "  (scaled from %.2f%%)",
404                                 100 * avg_running / avg_enabled);
405         }
406
407         fprintf(stderr, "\n");
408 }
409
410 static void print_stat(int argc, const char **argv)
411 {
412         int i, counter;
413
414         fflush(stdout);
415
416         fprintf(stderr, "\n");
417         fprintf(stderr, " Performance counter stats for \'%s", argv[0]);
418
419         for (i = 1; i < argc; i++)
420                 fprintf(stderr, " %s", argv[i]);
421
422         fprintf(stderr, "\'");
423         if (run_count > 1)
424                 fprintf(stderr, " (%d runs)", run_count);
425         fprintf(stderr, ":\n\n");
426
427         for (counter = 0; counter < nr_counters; counter++)
428                 print_counter(counter);
429
430         fprintf(stderr, "\n");
431         fprintf(stderr, " %14.9f  seconds time elapsed",
432                         avg_stats(&walltime_nsecs_stats)/1e9);
433         if (run_count > 1) {
434                 fprintf(stderr, "   ( +- %7.3f%% )",
435                                 100*stddev_stats(&walltime_nsecs_stats) /
436                                 avg_stats(&walltime_nsecs_stats));
437         }
438         fprintf(stderr, "\n\n");
439 }
440
441 static volatile int signr = -1;
442
443 static void skip_signal(int signo)
444 {
445         signr = signo;
446 }
447
448 static void sig_atexit(void)
449 {
450         if (child_pid != -1)
451                 kill(child_pid, SIGTERM);
452
453         if (signr == -1)
454                 return;
455
456         signal(signr, SIG_DFL);
457         kill(getpid(), signr);
458 }
459
460 static const char * const stat_usage[] = {
461         "perf stat [<options>] <command>",
462         NULL
463 };
464
465 static const struct option options[] = {
466         OPT_CALLBACK('e', "event", NULL, "event",
467                      "event selector. use 'perf list' to list available events",
468                      parse_events),
469         OPT_BOOLEAN('i', "inherit", &inherit,
470                     "child tasks inherit counters"),
471         OPT_INTEGER('p', "pid", &target_pid,
472                     "stat events on existing pid"),
473         OPT_BOOLEAN('a', "all-cpus", &system_wide,
474                     "system-wide collection from all CPUs"),
475         OPT_BOOLEAN('c', "scale", &scale,
476                     "scale/normalize counters"),
477         OPT_BOOLEAN('v', "verbose", &verbose,
478                     "be more verbose (show counter open errors, etc)"),
479         OPT_INTEGER('r', "repeat", &run_count,
480                     "repeat command and print average + stddev (max: 100)"),
481         OPT_BOOLEAN('n', "null", &null_run,
482                     "null run - dont start any counters"),
483         OPT_END()
484 };
485
486 int cmd_stat(int argc, const char **argv, const char *prefix __used)
487 {
488         int status;
489
490         argc = parse_options(argc, argv, options, stat_usage,
491                 PARSE_OPT_STOP_AT_NON_OPTION);
492         if (!argc)
493                 usage_with_options(stat_usage, options);
494         if (run_count <= 0)
495                 usage_with_options(stat_usage, options);
496
497         /* Set attrs and nr_counters if no event is selected and !null_run */
498         if (!null_run && !nr_counters) {
499                 memcpy(attrs, default_attrs, sizeof(default_attrs));
500                 nr_counters = ARRAY_SIZE(default_attrs);
501         }
502
503         nr_cpus = sysconf(_SC_NPROCESSORS_ONLN);
504         assert(nr_cpus <= MAX_NR_CPUS);
505         assert((int)nr_cpus >= 0);
506
507         /*
508          * We dont want to block the signals - that would cause
509          * child tasks to inherit that and Ctrl-C would not work.
510          * What we want is for Ctrl-C to work in the exec()-ed
511          * task, but being ignored by perf stat itself:
512          */
513         atexit(sig_atexit);
514         signal(SIGINT,  skip_signal);
515         signal(SIGALRM, skip_signal);
516         signal(SIGABRT, skip_signal);
517
518         status = 0;
519         for (run_idx = 0; run_idx < run_count; run_idx++) {
520                 if (run_count != 1 && verbose)
521                         fprintf(stderr, "[ perf stat: executing run #%d ... ]\n", run_idx + 1);
522                 status = run_perf_stat(argc, argv);
523         }
524
525         print_stat(argc, argv);
526
527         return status;
528 }