Merge branch 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[linux-2.6.git] / 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
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 int                      target_pid                      = -1;
73 static int                      null_run                        =  0;
74
75 static int                      fd[MAX_NR_CPUS][MAX_COUNTERS];
76
77 static int                      event_scaled[MAX_COUNTERS];
78
79 struct stats
80 {
81         double n, mean, M2;
82 };
83
84 static void update_stats(struct stats *stats, u64 val)
85 {
86         double delta;
87
88         stats->n++;
89         delta = val - stats->mean;
90         stats->mean += delta / stats->n;
91         stats->M2 += delta*(val - stats->mean);
92 }
93
94 static double avg_stats(struct stats *stats)
95 {
96         return stats->mean;
97 }
98
99 /*
100  * http://en.wikipedia.org/wiki/Algorithms_for_calculating_variance
101  *
102  *       (\Sum n_i^2) - ((\Sum n_i)^2)/n
103  * s^2 = -------------------------------
104  *                  n - 1
105  *
106  * http://en.wikipedia.org/wiki/Stddev
107  *
108  * The std dev of the mean is related to the std dev by:
109  *
110  *             s
111  * s_mean = -------
112  *          sqrt(n)
113  *
114  */
115 static double stddev_stats(struct stats *stats)
116 {
117         double variance = stats->M2 / (stats->n - 1);
118         double variance_mean = variance / stats->n;
119
120         return sqrt(variance_mean);
121 }
122
123 struct stats                    event_res_stats[MAX_COUNTERS][3];
124 struct stats                    runtime_nsecs_stats;
125 struct stats                    walltime_nsecs_stats;
126 struct stats                    runtime_cycles_stats;
127
128 #define MATCH_EVENT(t, c, counter)                      \
129         (attrs[counter].type == PERF_TYPE_##t &&        \
130          attrs[counter].config == PERF_COUNT_##c)
131
132 #define ERR_PERF_OPEN \
133 "Error: counter %d, sys_perf_event_open() syscall returned with %d (%s)\n"
134
135 static void create_perf_stat_counter(int counter, int pid)
136 {
137         struct perf_event_attr *attr = attrs + counter;
138
139         if (scale)
140                 attr->read_format = PERF_FORMAT_TOTAL_TIME_ENABLED |
141                                     PERF_FORMAT_TOTAL_TIME_RUNNING;
142
143         if (system_wide) {
144                 unsigned int cpu;
145
146                 for (cpu = 0; cpu < nr_cpus; cpu++) {
147                         fd[cpu][counter] = sys_perf_event_open(attr, -1, cpu, -1, 0);
148                         if (fd[cpu][counter] < 0 && verbose)
149                                 fprintf(stderr, ERR_PERF_OPEN, counter,
150                                         fd[cpu][counter], strerror(errno));
151                 }
152         } else {
153                 attr->inherit        = inherit;
154                 attr->disabled       = 1;
155                 attr->enable_on_exec = 1;
156
157                 fd[0][counter] = sys_perf_event_open(attr, pid, -1, -1, 0);
158                 if (fd[0][counter] < 0 && verbose)
159                         fprintf(stderr, ERR_PERF_OPEN, counter,
160                                 fd[0][counter], strerror(errno));
161         }
162 }
163
164 /*
165  * Does the counter have nsecs as a unit?
166  */
167 static inline int nsec_counter(int counter)
168 {
169         if (MATCH_EVENT(SOFTWARE, SW_CPU_CLOCK, counter) ||
170             MATCH_EVENT(SOFTWARE, SW_TASK_CLOCK, counter))
171                 return 1;
172
173         return 0;
174 }
175
176 /*
177  * Read out the results of a single counter:
178  */
179 static void read_counter(int counter)
180 {
181         u64 count[3], single_count[3];
182         unsigned int cpu;
183         size_t res, nv;
184         int scaled;
185         int i;
186
187         count[0] = count[1] = count[2] = 0;
188
189         nv = scale ? 3 : 1;
190         for (cpu = 0; cpu < nr_cpus; cpu++) {
191                 if (fd[cpu][counter] < 0)
192                         continue;
193
194                 res = read(fd[cpu][counter], single_count, nv * sizeof(u64));
195                 assert(res == nv * sizeof(u64));
196
197                 close(fd[cpu][counter]);
198                 fd[cpu][counter] = -1;
199
200                 count[0] += single_count[0];
201                 if (scale) {
202                         count[1] += single_count[1];
203                         count[2] += single_count[2];
204                 }
205         }
206
207         scaled = 0;
208         if (scale) {
209                 if (count[2] == 0) {
210                         event_scaled[counter] = -1;
211                         count[0] = 0;
212                         return;
213                 }
214
215                 if (count[2] < count[1]) {
216                         event_scaled[counter] = 1;
217                         count[0] = (unsigned long long)
218                                 ((double)count[0] * count[1] / count[2] + 0.5);
219                 }
220         }
221
222         for (i = 0; i < 3; i++)
223                 update_stats(&event_res_stats[counter][i], count[i]);
224
225         if (verbose) {
226                 fprintf(stderr, "%s: %Ld %Ld %Ld\n", event_name(counter),
227                                 count[0], count[1], count[2]);
228         }
229
230         /*
231          * Save the full runtime - to allow normalization during printout:
232          */
233         if (MATCH_EVENT(SOFTWARE, SW_TASK_CLOCK, counter))
234                 update_stats(&runtime_nsecs_stats, count[0]);
235         if (MATCH_EVENT(HARDWARE, HW_CPU_CYCLES, counter))
236                 update_stats(&runtime_cycles_stats, count[0]);
237 }
238
239 static int run_perf_stat(int argc __used, const char **argv)
240 {
241         unsigned long long t0, t1;
242         int status = 0;
243         int counter;
244         int pid;
245         int child_ready_pipe[2], go_pipe[2];
246         char buf;
247
248         if (!system_wide)
249                 nr_cpus = 1;
250
251         if (pipe(child_ready_pipe) < 0 || pipe(go_pipe) < 0) {
252                 perror("failed to create pipes");
253                 exit(1);
254         }
255
256         if ((pid = fork()) < 0)
257                 perror("failed to fork");
258
259         if (!pid) {
260                 close(child_ready_pipe[0]);
261                 close(go_pipe[1]);
262                 fcntl(go_pipe[0], F_SETFD, FD_CLOEXEC);
263
264                 /*
265                  * Do a dummy execvp to get the PLT entry resolved,
266                  * so we avoid the resolver overhead on the real
267                  * execvp call.
268                  */
269                 execvp("", (char **)argv);
270
271                 /*
272                  * Tell the parent we're ready to go
273                  */
274                 close(child_ready_pipe[1]);
275
276                 /*
277                  * Wait until the parent tells us to go.
278                  */
279                 if (read(go_pipe[0], &buf, 1) == -1)
280                         perror("unable to read pipe");
281
282                 execvp(argv[0], (char **)argv);
283
284                 perror(argv[0]);
285                 exit(-1);
286         }
287
288         /*
289          * Wait for the child to be ready to exec.
290          */
291         close(child_ready_pipe[1]);
292         close(go_pipe[0]);
293         if (read(child_ready_pipe[0], &buf, 1) == -1)
294                 perror("unable to read pipe");
295         close(child_ready_pipe[0]);
296
297         for (counter = 0; counter < nr_counters; counter++)
298                 create_perf_stat_counter(counter, pid);
299
300         /*
301          * Enable counters and exec the command:
302          */
303         t0 = rdclock();
304
305         close(go_pipe[1]);
306         wait(&status);
307
308         t1 = rdclock();
309
310         update_stats(&walltime_nsecs_stats, t1 - t0);
311
312         for (counter = 0; counter < nr_counters; counter++)
313                 read_counter(counter);
314
315         return WEXITSTATUS(status);
316 }
317
318 static void print_noise(int counter, double avg)
319 {
320         if (run_count == 1)
321                 return;
322
323         fprintf(stderr, "   ( +- %7.3f%% )",
324                         100 * stddev_stats(&event_res_stats[counter][0]) / avg);
325 }
326
327 static void nsec_printout(int counter, double avg)
328 {
329         double msecs = avg / 1e6;
330
331         fprintf(stderr, " %14.6f  %-24s", msecs, event_name(counter));
332
333         if (MATCH_EVENT(SOFTWARE, SW_TASK_CLOCK, counter)) {
334                 fprintf(stderr, " # %10.3f CPUs ",
335                                 avg / avg_stats(&walltime_nsecs_stats));
336         }
337 }
338
339 static void abs_printout(int counter, double avg)
340 {
341         double total, ratio = 0.0;
342
343         fprintf(stderr, " %14.0f  %-24s", avg, event_name(counter));
344
345         if (MATCH_EVENT(HARDWARE, HW_INSTRUCTIONS, counter)) {
346                 total = avg_stats(&runtime_cycles_stats);
347
348                 if (total)
349                         ratio = avg / total;
350
351                 fprintf(stderr, " # %10.3f IPC  ", ratio);
352         } else {
353                 total = avg_stats(&runtime_nsecs_stats);
354
355                 if (total)
356                         ratio = 1000.0 * avg / total;
357
358                 fprintf(stderr, " # %10.3f M/sec", ratio);
359         }
360 }
361
362 /*
363  * Print out the results of a single counter:
364  */
365 static void print_counter(int counter)
366 {
367         double avg = avg_stats(&event_res_stats[counter][0]);
368         int scaled = event_scaled[counter];
369
370         if (scaled == -1) {
371                 fprintf(stderr, " %14s  %-24s\n",
372                         "<not counted>", event_name(counter));
373                 return;
374         }
375
376         if (nsec_counter(counter))
377                 nsec_printout(counter, avg);
378         else
379                 abs_printout(counter, avg);
380
381         print_noise(counter, avg);
382
383         if (scaled) {
384                 double avg_enabled, avg_running;
385
386                 avg_enabled = avg_stats(&event_res_stats[counter][1]);
387                 avg_running = avg_stats(&event_res_stats[counter][2]);
388
389                 fprintf(stderr, "  (scaled from %.2f%%)",
390                                 100 * avg_running / avg_enabled);
391         }
392
393         fprintf(stderr, "\n");
394 }
395
396 static void print_stat(int argc, const char **argv)
397 {
398         int i, counter;
399
400         fflush(stdout);
401
402         fprintf(stderr, "\n");
403         fprintf(stderr, " Performance counter stats for \'%s", argv[0]);
404
405         for (i = 1; i < argc; i++)
406                 fprintf(stderr, " %s", argv[i]);
407
408         fprintf(stderr, "\'");
409         if (run_count > 1)
410                 fprintf(stderr, " (%d runs)", run_count);
411         fprintf(stderr, ":\n\n");
412
413         for (counter = 0; counter < nr_counters; counter++)
414                 print_counter(counter);
415
416         fprintf(stderr, "\n");
417         fprintf(stderr, " %14.9f  seconds time elapsed",
418                         avg_stats(&walltime_nsecs_stats)/1e9);
419         if (run_count > 1) {
420                 fprintf(stderr, "   ( +- %7.3f%% )",
421                                 100*stddev_stats(&walltime_nsecs_stats) /
422                                 avg_stats(&walltime_nsecs_stats));
423         }
424         fprintf(stderr, "\n\n");
425 }
426
427 static volatile int signr = -1;
428
429 static void skip_signal(int signo)
430 {
431         signr = signo;
432 }
433
434 static void sig_atexit(void)
435 {
436         if (signr == -1)
437                 return;
438
439         signal(signr, SIG_DFL);
440         kill(getpid(), signr);
441 }
442
443 static const char * const stat_usage[] = {
444         "perf stat [<options>] <command>",
445         NULL
446 };
447
448 static const struct option options[] = {
449         OPT_CALLBACK('e', "event", NULL, "event",
450                      "event selector. use 'perf list' to list available events",
451                      parse_events),
452         OPT_BOOLEAN('i', "inherit", &inherit,
453                     "child tasks inherit counters"),
454         OPT_INTEGER('p', "pid", &target_pid,
455                     "stat events on existing pid"),
456         OPT_BOOLEAN('a', "all-cpus", &system_wide,
457                     "system-wide collection from all CPUs"),
458         OPT_BOOLEAN('c', "scale", &scale,
459                     "scale/normalize counters"),
460         OPT_BOOLEAN('v', "verbose", &verbose,
461                     "be more verbose (show counter open errors, etc)"),
462         OPT_INTEGER('r', "repeat", &run_count,
463                     "repeat command and print average + stddev (max: 100)"),
464         OPT_BOOLEAN('n', "null", &null_run,
465                     "null run - dont start any counters"),
466         OPT_END()
467 };
468
469 int cmd_stat(int argc, const char **argv, const char *prefix __used)
470 {
471         int status;
472
473         argc = parse_options(argc, argv, options, stat_usage,
474                 PARSE_OPT_STOP_AT_NON_OPTION);
475         if (!argc)
476                 usage_with_options(stat_usage, options);
477         if (run_count <= 0)
478                 usage_with_options(stat_usage, options);
479
480         /* Set attrs and nr_counters if no event is selected and !null_run */
481         if (!null_run && !nr_counters) {
482                 memcpy(attrs, default_attrs, sizeof(default_attrs));
483                 nr_counters = ARRAY_SIZE(default_attrs);
484         }
485
486         nr_cpus = sysconf(_SC_NPROCESSORS_ONLN);
487         assert(nr_cpus <= MAX_NR_CPUS);
488         assert((int)nr_cpus >= 0);
489
490         /*
491          * We dont want to block the signals - that would cause
492          * child tasks to inherit that and Ctrl-C would not work.
493          * What we want is for Ctrl-C to work in the exec()-ed
494          * task, but being ignored by perf stat itself:
495          */
496         atexit(sig_atexit);
497         signal(SIGINT,  skip_signal);
498         signal(SIGALRM, skip_signal);
499         signal(SIGABRT, skip_signal);
500
501         status = 0;
502         for (run_idx = 0; run_idx < run_count; run_idx++) {
503                 if (run_count != 1 && verbose)
504                         fprintf(stderr, "[ perf stat: executing run #%d ... ]\n", run_idx + 1);
505                 status = run_perf_stat(argc, argv);
506         }
507
508         print_stat(argc, argv);
509
510         return status;
511 }