dc61f1b68b40a745ce65dca57259e4277af74e63
[linux-3.10.git] / tools / perf / builtin-record.c
1 /*
2  * builtin-record.c
3  *
4  * Builtin record command: Record the profile of a workload
5  * (or a CPU, or a PID) into the perf.data output file - for
6  * later analysis via perf report.
7  */
8 #define _FILE_OFFSET_BITS 64
9
10 #include "builtin.h"
11
12 #include "perf.h"
13
14 #include "util/build-id.h"
15 #include "util/util.h"
16 #include "util/parse-options.h"
17 #include "util/parse-events.h"
18
19 #include "util/header.h"
20 #include "util/event.h"
21 #include "util/debug.h"
22 #include "util/session.h"
23 #include "util/symbol.h"
24 #include "util/cpumap.h"
25
26 #include <unistd.h>
27 #include <sched.h>
28
29 static int                      *fd[MAX_NR_CPUS][MAX_COUNTERS];
30
31 static long                     default_interval                =      0;
32
33 static int                      nr_cpus                         =      0;
34 static unsigned int             page_size;
35 static unsigned int             mmap_pages                      =    128;
36 static int                      freq                            =   1000;
37 static int                      output;
38 static const char               *output_name                    = "perf.data";
39 static int                      group                           =      0;
40 static unsigned int             realtime_prio                   =      0;
41 static int                      raw_samples                     =      0;
42 static int                      system_wide                     =      0;
43 static int                      profile_cpu                     =     -1;
44 static pid_t                    target_pid                      =     -1;
45 static pid_t                    target_tid                      =     -1;
46 static pid_t                    *all_tids                       =      NULL;
47 static int                      thread_num                      =      0;
48 static pid_t                    child_pid                       =     -1;
49 static int                      inherit                         =      1;
50 static int                      force                           =      0;
51 static int                      append_file                     =      0;
52 static int                      call_graph                      =      0;
53 static int                      inherit_stat                    =      0;
54 static int                      no_samples                      =      0;
55 static int                      sample_address                  =      0;
56 static int                      multiplex                       =      0;
57 static int                      multiplex_fd                    =     -1;
58
59 static long                     samples                         =      0;
60 static struct timeval           last_read;
61 static struct timeval           this_read;
62
63 static u64                      bytes_written                   =      0;
64
65 static struct pollfd            *event_array;
66
67 static int                      nr_poll                         =      0;
68 static int                      nr_cpu                          =      0;
69
70 static int                      file_new                        =      1;
71 static off_t                    post_processing_offset;
72
73 static struct perf_session      *session;
74
75 struct mmap_data {
76         int                     counter;
77         void                    *base;
78         unsigned int            mask;
79         unsigned int            prev;
80 };
81
82 static struct mmap_data         *mmap_array[MAX_NR_CPUS][MAX_COUNTERS];
83
84 static unsigned long mmap_read_head(struct mmap_data *md)
85 {
86         struct perf_event_mmap_page *pc = md->base;
87         long head;
88
89         head = pc->data_head;
90         rmb();
91
92         return head;
93 }
94
95 static void mmap_write_tail(struct mmap_data *md, unsigned long tail)
96 {
97         struct perf_event_mmap_page *pc = md->base;
98
99         /*
100          * ensure all reads are done before we write the tail out.
101          */
102         /* mb(); */
103         pc->data_tail = tail;
104 }
105
106 static void write_output(void *buf, size_t size)
107 {
108         while (size) {
109                 int ret = write(output, buf, size);
110
111                 if (ret < 0)
112                         die("failed to write");
113
114                 size -= ret;
115                 buf += ret;
116
117                 bytes_written += ret;
118         }
119 }
120
121 static int process_synthesized_event(event_t *event,
122                                      struct perf_session *self __used)
123 {
124         write_output(event, event->header.size);
125         return 0;
126 }
127
128 static void mmap_read(struct mmap_data *md)
129 {
130         unsigned int head = mmap_read_head(md);
131         unsigned int old = md->prev;
132         unsigned char *data = md->base + page_size;
133         unsigned long size;
134         void *buf;
135         int diff;
136
137         gettimeofday(&this_read, NULL);
138
139         /*
140          * If we're further behind than half the buffer, there's a chance
141          * the writer will bite our tail and mess up the samples under us.
142          *
143          * If we somehow ended up ahead of the head, we got messed up.
144          *
145          * In either case, truncate and restart at head.
146          */
147         diff = head - old;
148         if (diff < 0) {
149                 struct timeval iv;
150                 unsigned long msecs;
151
152                 timersub(&this_read, &last_read, &iv);
153                 msecs = iv.tv_sec*1000 + iv.tv_usec/1000;
154
155                 fprintf(stderr, "WARNING: failed to keep up with mmap data."
156                                 "  Last read %lu msecs ago.\n", msecs);
157
158                 /*
159                  * head points to a known good entry, start there.
160                  */
161                 old = head;
162         }
163
164         last_read = this_read;
165
166         if (old != head)
167                 samples++;
168
169         size = head - old;
170
171         if ((old & md->mask) + size != (head & md->mask)) {
172                 buf = &data[old & md->mask];
173                 size = md->mask + 1 - (old & md->mask);
174                 old += size;
175
176                 write_output(buf, size);
177         }
178
179         buf = &data[old & md->mask];
180         size = head - old;
181         old += size;
182
183         write_output(buf, size);
184
185         md->prev = old;
186         mmap_write_tail(md, old);
187 }
188
189 static volatile int done = 0;
190 static volatile int signr = -1;
191
192 static void sig_handler(int sig)
193 {
194         done = 1;
195         signr = sig;
196 }
197
198 static void sig_atexit(void)
199 {
200         if (child_pid != -1)
201                 kill(child_pid, SIGTERM);
202
203         if (signr == -1)
204                 return;
205
206         signal(signr, SIG_DFL);
207         kill(getpid(), signr);
208 }
209
210 static int group_fd;
211
212 static struct perf_header_attr *get_header_attr(struct perf_event_attr *a, int nr)
213 {
214         struct perf_header_attr *h_attr;
215
216         if (nr < session->header.attrs) {
217                 h_attr = session->header.attr[nr];
218         } else {
219                 h_attr = perf_header_attr__new(a);
220                 if (h_attr != NULL)
221                         if (perf_header__add_attr(&session->header, h_attr) < 0) {
222                                 perf_header_attr__delete(h_attr);
223                                 h_attr = NULL;
224                         }
225         }
226
227         return h_attr;
228 }
229
230 static void create_counter(int counter, int cpu)
231 {
232         char *filter = filters[counter];
233         struct perf_event_attr *attr = attrs + counter;
234         struct perf_header_attr *h_attr;
235         int track = !counter; /* only the first counter needs these */
236         int thread_index;
237         int ret;
238         struct {
239                 u64 count;
240                 u64 time_enabled;
241                 u64 time_running;
242                 u64 id;
243         } read_data;
244
245         attr->read_format       = PERF_FORMAT_TOTAL_TIME_ENABLED |
246                                   PERF_FORMAT_TOTAL_TIME_RUNNING |
247                                   PERF_FORMAT_ID;
248
249         attr->sample_type       |= PERF_SAMPLE_IP | PERF_SAMPLE_TID;
250
251         if (nr_counters > 1)
252                 attr->sample_type |= PERF_SAMPLE_ID;
253
254         if (freq) {
255                 attr->sample_type       |= PERF_SAMPLE_PERIOD;
256                 attr->freq              = 1;
257                 attr->sample_freq       = freq;
258         }
259
260         if (no_samples)
261                 attr->sample_freq = 0;
262
263         if (inherit_stat)
264                 attr->inherit_stat = 1;
265
266         if (sample_address)
267                 attr->sample_type       |= PERF_SAMPLE_ADDR;
268
269         if (call_graph)
270                 attr->sample_type       |= PERF_SAMPLE_CALLCHAIN;
271
272         if (raw_samples) {
273                 attr->sample_type       |= PERF_SAMPLE_TIME;
274                 attr->sample_type       |= PERF_SAMPLE_RAW;
275                 attr->sample_type       |= PERF_SAMPLE_CPU;
276         }
277
278         attr->mmap              = track;
279         attr->comm              = track;
280         attr->inherit           = inherit;
281         if (target_pid == -1 && !system_wide) {
282                 attr->disabled = 1;
283                 attr->enable_on_exec = 1;
284         }
285
286         for (thread_index = 0; thread_index < thread_num; thread_index++) {
287 try_again:
288                 fd[nr_cpu][counter][thread_index] = sys_perf_event_open(attr,
289                                 all_tids[thread_index], cpu, group_fd, 0);
290
291                 if (fd[nr_cpu][counter][thread_index] < 0) {
292                         int err = errno;
293
294                         if (err == EPERM || err == EACCES)
295                                 die("Permission error - are you root?\n"
296                                         "\t Consider tweaking"
297                                         " /proc/sys/kernel/perf_event_paranoid.\n");
298                         else if (err ==  ENODEV && profile_cpu != -1) {
299                                 die("No such device - did you specify"
300                                         " an out-of-range profile CPU?\n");
301                         }
302
303                         /*
304                          * If it's cycles then fall back to hrtimer
305                          * based cpu-clock-tick sw counter, which
306                          * is always available even if no PMU support:
307                          */
308                         if (attr->type == PERF_TYPE_HARDWARE
309                                         && attr->config == PERF_COUNT_HW_CPU_CYCLES) {
310
311                                 if (verbose)
312                                         warning(" ... trying to fall back to cpu-clock-ticks\n");
313                                 attr->type = PERF_TYPE_SOFTWARE;
314                                 attr->config = PERF_COUNT_SW_CPU_CLOCK;
315                                 goto try_again;
316                         }
317                         printf("\n");
318                         error("perfcounter syscall returned with %d (%s)\n",
319                                         fd[nr_cpu][counter][thread_index], strerror(err));
320
321 #if defined(__i386__) || defined(__x86_64__)
322                         if (attr->type == PERF_TYPE_HARDWARE && err == EOPNOTSUPP)
323                                 die("No hardware sampling interrupt available."
324                                     " No APIC? If so then you can boot the kernel"
325                                     " with the \"lapic\" boot parameter to"
326                                     " force-enable it.\n");
327 #endif
328
329                         die("No CONFIG_PERF_EVENTS=y kernel support configured?\n");
330                         exit(-1);
331                 }
332
333                 h_attr = get_header_attr(attr, counter);
334                 if (h_attr == NULL)
335                         die("nomem\n");
336
337                 if (!file_new) {
338                         if (memcmp(&h_attr->attr, attr, sizeof(*attr))) {
339                                 fprintf(stderr, "incompatible append\n");
340                                 exit(-1);
341                         }
342                 }
343
344                 if (read(fd[nr_cpu][counter][thread_index], &read_data, sizeof(read_data)) == -1) {
345                         perror("Unable to read perf file descriptor\n");
346                         exit(-1);
347                 }
348
349                 if (perf_header_attr__add_id(h_attr, read_data.id) < 0) {
350                         pr_warning("Not enough memory to add id\n");
351                         exit(-1);
352                 }
353
354                 assert(fd[nr_cpu][counter][thread_index] >= 0);
355                 fcntl(fd[nr_cpu][counter][thread_index], F_SETFL, O_NONBLOCK);
356
357                 /*
358                  * First counter acts as the group leader:
359                  */
360                 if (group && group_fd == -1)
361                         group_fd = fd[nr_cpu][counter][thread_index];
362                 if (multiplex && multiplex_fd == -1)
363                         multiplex_fd = fd[nr_cpu][counter][thread_index];
364
365                 if (multiplex && fd[nr_cpu][counter][thread_index] != multiplex_fd) {
366
367                         ret = ioctl(fd[nr_cpu][counter][thread_index], PERF_EVENT_IOC_SET_OUTPUT, multiplex_fd);
368                         assert(ret != -1);
369                 } else {
370                         event_array[nr_poll].fd = fd[nr_cpu][counter][thread_index];
371                         event_array[nr_poll].events = POLLIN;
372                         nr_poll++;
373
374                         mmap_array[nr_cpu][counter][thread_index].counter = counter;
375                         mmap_array[nr_cpu][counter][thread_index].prev = 0;
376                         mmap_array[nr_cpu][counter][thread_index].mask = mmap_pages*page_size - 1;
377                         mmap_array[nr_cpu][counter][thread_index].base = mmap(NULL, (mmap_pages+1)*page_size,
378                                 PROT_READ|PROT_WRITE, MAP_SHARED, fd[nr_cpu][counter][thread_index], 0);
379                         if (mmap_array[nr_cpu][counter][thread_index].base == MAP_FAILED) {
380                                 error("failed to mmap with %d (%s)\n", errno, strerror(errno));
381                                 exit(-1);
382                         }
383                 }
384
385                 if (filter != NULL) {
386                         ret = ioctl(fd[nr_cpu][counter][thread_index],
387                                         PERF_EVENT_IOC_SET_FILTER, filter);
388                         if (ret) {
389                                 error("failed to set filter with %d (%s)\n", errno,
390                                                 strerror(errno));
391                                 exit(-1);
392                         }
393                 }
394         }
395 }
396
397 static void open_counters(int cpu)
398 {
399         int counter;
400
401         group_fd = -1;
402         for (counter = 0; counter < nr_counters; counter++)
403                 create_counter(counter, cpu);
404
405         nr_cpu++;
406 }
407
408 static int process_buildids(void)
409 {
410         u64 size = lseek(output, 0, SEEK_CUR);
411
412         if (size == 0)
413                 return 0;
414
415         session->fd = output;
416         return __perf_session__process_events(session, post_processing_offset,
417                                               size - post_processing_offset,
418                                               size, &build_id__mark_dso_hit_ops);
419 }
420
421 static void atexit_header(void)
422 {
423         session->header.data_size += bytes_written;
424
425         process_buildids();
426         perf_header__write(&session->header, output, true);
427 }
428
429 static int __cmd_record(int argc, const char **argv)
430 {
431         int i, counter;
432         struct stat st;
433         pid_t pid = 0;
434         int flags;
435         int err;
436         unsigned long waking = 0;
437         int child_ready_pipe[2], go_pipe[2];
438         const bool forks = argc > 0;
439         char buf;
440
441         page_size = sysconf(_SC_PAGE_SIZE);
442
443         atexit(sig_atexit);
444         signal(SIGCHLD, sig_handler);
445         signal(SIGINT, sig_handler);
446
447         if (forks && (pipe(child_ready_pipe) < 0 || pipe(go_pipe) < 0)) {
448                 perror("failed to create pipes");
449                 exit(-1);
450         }
451
452         if (!stat(output_name, &st) && st.st_size) {
453                 if (!force) {
454                         if (!append_file) {
455                                 pr_err("Error, output file %s exists, use -A "
456                                        "to append or -f to overwrite.\n",
457                                        output_name);
458                                 exit(-1);
459                         }
460                 } else {
461                         char oldname[PATH_MAX];
462                         snprintf(oldname, sizeof(oldname), "%s.old",
463                                  output_name);
464                         unlink(oldname);
465                         rename(output_name, oldname);
466                 }
467         } else {
468                 append_file = 0;
469         }
470
471         flags = O_CREAT|O_RDWR;
472         if (append_file)
473                 file_new = 0;
474         else
475                 flags |= O_TRUNC;
476
477         output = open(output_name, flags, S_IRUSR|S_IWUSR);
478         if (output < 0) {
479                 perror("failed to create output file");
480                 exit(-1);
481         }
482
483         session = perf_session__new(output_name, O_WRONLY, force);
484         if (session == NULL) {
485                 pr_err("Not enough memory for reading perf file header\n");
486                 return -1;
487         }
488
489         if (!file_new) {
490                 err = perf_header__read(&session->header, output);
491                 if (err < 0)
492                         return err;
493         }
494
495         if (raw_samples) {
496                 perf_header__set_feat(&session->header, HEADER_TRACE_INFO);
497         } else {
498                 for (i = 0; i < nr_counters; i++) {
499                         if (attrs[i].sample_type & PERF_SAMPLE_RAW) {
500                                 perf_header__set_feat(&session->header, HEADER_TRACE_INFO);
501                                 break;
502                         }
503                 }
504         }
505
506         atexit(atexit_header);
507
508         if (forks) {
509                 child_pid = fork();
510                 if (pid < 0) {
511                         perror("failed to fork");
512                         exit(-1);
513                 }
514
515                 if (!child_pid) {
516                         close(child_ready_pipe[0]);
517                         close(go_pipe[1]);
518                         fcntl(go_pipe[0], F_SETFD, FD_CLOEXEC);
519
520                         /*
521                          * Do a dummy execvp to get the PLT entry resolved,
522                          * so we avoid the resolver overhead on the real
523                          * execvp call.
524                          */
525                         execvp("", (char **)argv);
526
527                         /*
528                          * Tell the parent we're ready to go
529                          */
530                         close(child_ready_pipe[1]);
531
532                         /*
533                          * Wait until the parent tells us to go.
534                          */
535                         if (read(go_pipe[0], &buf, 1) == -1)
536                                 perror("unable to read pipe");
537
538                         execvp(argv[0], (char **)argv);
539
540                         perror(argv[0]);
541                         exit(-1);
542                 }
543
544                 if (!system_wide && target_tid == -1 && target_pid == -1)
545                         all_tids[0] = child_pid;
546
547                 close(child_ready_pipe[1]);
548                 close(go_pipe[0]);
549                 /*
550                  * wait for child to settle
551                  */
552                 if (read(child_ready_pipe[0], &buf, 1) == -1) {
553                         perror("unable to read pipe");
554                         exit(-1);
555                 }
556                 close(child_ready_pipe[0]);
557         }
558
559         if ((!system_wide && !inherit) || profile_cpu != -1) {
560                 open_counters(profile_cpu);
561         } else {
562                 nr_cpus = read_cpu_map();
563                 for (i = 0; i < nr_cpus; i++)
564                         open_counters(cpumap[i]);
565         }
566
567         if (file_new) {
568                 err = perf_header__write(&session->header, output, false);
569                 if (err < 0)
570                         return err;
571         }
572
573         post_processing_offset = lseek(output, 0, SEEK_CUR);
574
575         err = event__synthesize_kernel_mmap(process_synthesized_event,
576                                             session, "_text");
577         if (err < 0)
578                 err = event__synthesize_kernel_mmap(process_synthesized_event,
579                                                     session, "_stext");
580         if (err < 0) {
581                 pr_err("Couldn't record kernel reference relocation symbol.\n");
582                 return err;
583         }
584
585         err = event__synthesize_modules(process_synthesized_event, session);
586         if (err < 0) {
587                 pr_err("Couldn't record kernel reference relocation symbol.\n");
588                 return err;
589         }
590
591         if (!system_wide && profile_cpu == -1)
592                 event__synthesize_thread(target_tid, process_synthesized_event,
593                                          session);
594         else
595                 event__synthesize_threads(process_synthesized_event, session);
596
597         if (realtime_prio) {
598                 struct sched_param param;
599
600                 param.sched_priority = realtime_prio;
601                 if (sched_setscheduler(0, SCHED_FIFO, &param)) {
602                         pr_err("Could not set realtime priority.\n");
603                         exit(-1);
604                 }
605         }
606
607         /*
608          * Let the child rip
609          */
610         if (forks)
611                 close(go_pipe[1]);
612
613         for (;;) {
614                 int hits = samples;
615                 int thread;
616
617                 for (i = 0; i < nr_cpu; i++) {
618                         for (counter = 0; counter < nr_counters; counter++) {
619                                 for (thread = 0;
620                                         thread < thread_num; thread++) {
621                                         if (mmap_array[i][counter][thread].base)
622                                                 mmap_read(&mmap_array[i][counter][thread]);
623                                 }
624
625                         }
626                 }
627
628                 if (hits == samples) {
629                         if (done)
630                                 break;
631                         err = poll(event_array, nr_poll, -1);
632                         waking++;
633                 }
634
635                 if (done) {
636                         for (i = 0; i < nr_cpu; i++) {
637                                 for (counter = 0;
638                                         counter < nr_counters;
639                                         counter++) {
640                                         for (thread = 0;
641                                                 thread < thread_num;
642                                                 thread++)
643                                                 ioctl(fd[i][counter][thread],
644                                                         PERF_EVENT_IOC_DISABLE);
645                                 }
646                         }
647                 }
648         }
649
650         fprintf(stderr, "[ perf record: Woken up %ld times to write data ]\n", waking);
651
652         /*
653          * Approximate RIP event size: 24 bytes.
654          */
655         fprintf(stderr,
656                 "[ perf record: Captured and wrote %.3f MB %s (~%lld samples) ]\n",
657                 (double)bytes_written / 1024.0 / 1024.0,
658                 output_name,
659                 bytes_written / 24);
660
661         return 0;
662 }
663
664 static const char * const record_usage[] = {
665         "perf record [<options>] [<command>]",
666         "perf record [<options>] -- <command> [<options>]",
667         NULL
668 };
669
670 static const struct option options[] = {
671         OPT_CALLBACK('e', "event", NULL, "event",
672                      "event selector. use 'perf list' to list available events",
673                      parse_events),
674         OPT_CALLBACK(0, "filter", NULL, "filter",
675                      "event filter", parse_filter),
676         OPT_INTEGER('p', "pid", &target_pid,
677                     "record events on existing process id"),
678         OPT_INTEGER('t', "tid", &target_tid,
679                     "record events on existing thread id"),
680         OPT_INTEGER('r', "realtime", &realtime_prio,
681                     "collect data with this RT SCHED_FIFO priority"),
682         OPT_BOOLEAN('R', "raw-samples", &raw_samples,
683                     "collect raw sample records from all opened counters"),
684         OPT_BOOLEAN('a', "all-cpus", &system_wide,
685                             "system-wide collection from all CPUs"),
686         OPT_BOOLEAN('A', "append", &append_file,
687                             "append to the output file to do incremental profiling"),
688         OPT_INTEGER('C', "profile_cpu", &profile_cpu,
689                             "CPU to profile on"),
690         OPT_BOOLEAN('f', "force", &force,
691                         "overwrite existing data file"),
692         OPT_LONG('c', "count", &default_interval,
693                     "event period to sample"),
694         OPT_STRING('o', "output", &output_name, "file",
695                     "output file name"),
696         OPT_BOOLEAN('i', "inherit", &inherit,
697                     "child tasks inherit counters"),
698         OPT_INTEGER('F', "freq", &freq,
699                     "profile at this frequency"),
700         OPT_INTEGER('m', "mmap-pages", &mmap_pages,
701                     "number of mmap data pages"),
702         OPT_BOOLEAN('g', "call-graph", &call_graph,
703                     "do call-graph (stack chain/backtrace) recording"),
704         OPT_BOOLEAN('v', "verbose", &verbose,
705                     "be more verbose (show counter open errors, etc)"),
706         OPT_BOOLEAN('s', "stat", &inherit_stat,
707                     "per thread counts"),
708         OPT_BOOLEAN('d', "data", &sample_address,
709                     "Sample addresses"),
710         OPT_BOOLEAN('n', "no-samples", &no_samples,
711                     "don't sample"),
712         OPT_BOOLEAN('M', "multiplex", &multiplex,
713                     "multiplex counter output in a single channel"),
714         OPT_END()
715 };
716
717 int cmd_record(int argc, const char **argv, const char *prefix __used)
718 {
719         int counter;
720         int i,j;
721
722         argc = parse_options(argc, argv, options, record_usage,
723                             PARSE_OPT_STOP_AT_NON_OPTION);
724         if (!argc && target_pid == -1 && target_tid == -1 &&
725                 !system_wide && profile_cpu == -1)
726                 usage_with_options(record_usage, options);
727
728         symbol__init();
729
730         if (!nr_counters) {
731                 nr_counters     = 1;
732                 attrs[0].type   = PERF_TYPE_HARDWARE;
733                 attrs[0].config = PERF_COUNT_HW_CPU_CYCLES;
734         }
735
736         if (target_pid != -1) {
737                 target_tid = target_pid;
738                 thread_num = find_all_tid(target_pid, &all_tids);
739                 if (thread_num <= 0) {
740                         fprintf(stderr, "Can't find all threads of pid %d\n",
741                                         target_pid);
742                         usage_with_options(record_usage, options);
743                 }
744         } else {
745                 all_tids=malloc(sizeof(pid_t));
746                 if (!all_tids)
747                         return -ENOMEM;
748
749                 all_tids[0] = target_tid;
750                 thread_num = 1;
751         }
752
753         for (i = 0; i < MAX_NR_CPUS; i++) {
754                 for (j = 0; j < MAX_COUNTERS; j++) {
755                         fd[i][j] = malloc(sizeof(int)*thread_num);
756                         mmap_array[i][j] = zalloc(
757                                 sizeof(struct mmap_data)*thread_num);
758                         if (!fd[i][j] || !mmap_array[i][j])
759                                 return -ENOMEM;
760                 }
761         }
762         event_array = malloc(
763                 sizeof(struct pollfd)*MAX_NR_CPUS*MAX_COUNTERS*thread_num);
764         if (!event_array)
765                 return -ENOMEM;
766
767         /*
768          * User specified count overrides default frequency.
769          */
770         if (default_interval)
771                 freq = 0;
772         else if (freq) {
773                 default_interval = freq;
774         } else {
775                 fprintf(stderr, "frequency and count are zero, aborting\n");
776                 exit(EXIT_FAILURE);
777         }
778
779         for (counter = 0; counter < nr_counters; counter++) {
780                 if (attrs[counter].sample_period)
781                         continue;
782
783                 attrs[counter].sample_period = default_interval;
784         }
785
786         return __cmd_record(argc, argv);
787 }