Merge branch 'perf-fixes-for-linus-2' 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 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
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
136 static 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  * Does the counter have nsecs as a unit?
167  */
168 static 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  * Read out the results of a single counter:
179  */
180 static 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          * Save the full runtime - to allow normalization during printout:
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
240 static 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                  * Do a dummy execvp to get the PLT entry resolved,
267                  * so we avoid the resolver overhead on the real
268                  * execvp call.
269                  */
270                 execvp("", (char **)argv);
271
272                 /*
273                  * Tell the parent we're ready to go
274                  */
275                 close(child_ready_pipe[1]);
276
277                 /*
278                  * Wait until the parent tells us to go.
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          * Wait for the child to be ready to exec.
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          * Enable counters and exec the command:
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
321 static 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
330 static 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
342 static 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  * Print out the results of a single counter:
367  */
368 static 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
399 static 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
430 static volatile int signr = -1;
431
432 static void skip_signal(int signo)
433 {
434         signr = signo;
435 }
436
437 static 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
449 static const char * const stat_usage[] = {
450         "perf stat [<options>] <command>",
451         NULL
452 };
453
454 static 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
475 int 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         /* Set attrs and nr_counters if no event is selected and !null_run */
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          * We dont want to block the signals - that would cause
498          * child tasks to inherit that and Ctrl-C would not work.
499          * What we want is for Ctrl-C to work in the exec()-ed
500          * task, but being ignored by perf stat itself:
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 }