Merge branch 'x86-tsc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...
[cascardo/linux.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/evsel.h"
22 #include "util/debug.h"
23 #include "util/session.h"
24 #include "util/symbol.h"
25 #include "util/cpumap.h"
26
27 #include <unistd.h>
28 #include <sched.h>
29 #include <sys/mman.h>
30
31 #define FD(e, x, y) (*(int *)xyarray__entry(e->fd, x, y))
32
33 enum write_mode_t {
34         WRITE_FORCE,
35         WRITE_APPEND
36 };
37
38 static u64                      user_interval                   = ULLONG_MAX;
39 static u64                      default_interval                =      0;
40 static u64                      sample_type;
41
42 static struct cpu_map           *cpus;
43 static unsigned int             page_size;
44 static unsigned int             mmap_pages                      =    128;
45 static unsigned int             user_freq                       = UINT_MAX;
46 static int                      freq                            =   1000;
47 static int                      output;
48 static int                      pipe_output                     =      0;
49 static const char               *output_name                    = "perf.data";
50 static int                      group                           =      0;
51 static int                      realtime_prio                   =      0;
52 static bool                     raw_samples                     =  false;
53 static bool                     sample_id_all_avail             =   true;
54 static bool                     system_wide                     =  false;
55 static pid_t                    target_pid                      =     -1;
56 static pid_t                    target_tid                      =     -1;
57 static struct thread_map        *threads;
58 static pid_t                    child_pid                       =     -1;
59 static bool                     no_inherit                      =  false;
60 static enum write_mode_t        write_mode                      = WRITE_FORCE;
61 static bool                     call_graph                      =  false;
62 static bool                     inherit_stat                    =  false;
63 static bool                     no_samples                      =  false;
64 static bool                     sample_address                  =  false;
65 static bool                     sample_time                     =  false;
66 static bool                     no_buildid                      =  false;
67 static bool                     no_buildid_cache                =  false;
68
69 static long                     samples                         =      0;
70 static u64                      bytes_written                   =      0;
71
72 static struct pollfd            *event_array;
73
74 static int                      nr_poll                         =      0;
75 static int                      nr_cpu                          =      0;
76
77 static int                      file_new                        =      1;
78 static off_t                    post_processing_offset;
79
80 static struct perf_session      *session;
81 static const char               *cpu_list;
82
83 struct mmap_data {
84         void                    *base;
85         unsigned int            mask;
86         unsigned int            prev;
87 };
88
89 static struct mmap_data         mmap_array[MAX_NR_CPUS];
90
91 static unsigned long mmap_read_head(struct mmap_data *md)
92 {
93         struct perf_event_mmap_page *pc = md->base;
94         long head;
95
96         head = pc->data_head;
97         rmb();
98
99         return head;
100 }
101
102 static void mmap_write_tail(struct mmap_data *md, unsigned long tail)
103 {
104         struct perf_event_mmap_page *pc = md->base;
105
106         /*
107          * ensure all reads are done before we write the tail out.
108          */
109         /* mb(); */
110         pc->data_tail = tail;
111 }
112
113 static void advance_output(size_t size)
114 {
115         bytes_written += size;
116 }
117
118 static void write_output(void *buf, size_t size)
119 {
120         while (size) {
121                 int ret = write(output, buf, size);
122
123                 if (ret < 0)
124                         die("failed to write");
125
126                 size -= ret;
127                 buf += ret;
128
129                 bytes_written += ret;
130         }
131 }
132
133 static int process_synthesized_event(event_t *event,
134                                      struct sample_data *sample __used,
135                                      struct perf_session *self __used)
136 {
137         write_output(event, event->header.size);
138         return 0;
139 }
140
141 static void mmap_read(struct mmap_data *md)
142 {
143         unsigned int head = mmap_read_head(md);
144         unsigned int old = md->prev;
145         unsigned char *data = md->base + page_size;
146         unsigned long size;
147         void *buf;
148         int diff;
149
150         /*
151          * If we're further behind than half the buffer, there's a chance
152          * the writer will bite our tail and mess up the samples under us.
153          *
154          * If we somehow ended up ahead of the head, we got messed up.
155          *
156          * In either case, truncate and restart at head.
157          */
158         diff = head - old;
159         if (diff < 0) {
160                 fprintf(stderr, "WARNING: failed to keep up with mmap data\n");
161                 /*
162                  * head points to a known good entry, start there.
163                  */
164                 old = head;
165         }
166
167         if (old != head)
168                 samples++;
169
170         size = head - old;
171
172         if ((old & md->mask) + size != (head & md->mask)) {
173                 buf = &data[old & md->mask];
174                 size = md->mask + 1 - (old & md->mask);
175                 old += size;
176
177                 write_output(buf, size);
178         }
179
180         buf = &data[old & md->mask];
181         size = head - old;
182         old += size;
183
184         write_output(buf, size);
185
186         md->prev = old;
187         mmap_write_tail(md, old);
188 }
189
190 static volatile int done = 0;
191 static volatile int signr = -1;
192
193 static void sig_handler(int sig)
194 {
195         done = 1;
196         signr = sig;
197 }
198
199 static void sig_atexit(void)
200 {
201         if (child_pid > 0)
202                 kill(child_pid, SIGTERM);
203
204         if (signr == -1 || signr == SIGUSR1)
205                 return;
206
207         signal(signr, SIG_DFL);
208         kill(getpid(), signr);
209 }
210
211 static int group_fd;
212
213 static struct perf_header_attr *get_header_attr(struct perf_event_attr *a, int nr)
214 {
215         struct perf_header_attr *h_attr;
216
217         if (nr < session->header.attrs) {
218                 h_attr = session->header.attr[nr];
219         } else {
220                 h_attr = perf_header_attr__new(a);
221                 if (h_attr != NULL)
222                         if (perf_header__add_attr(&session->header, h_attr) < 0) {
223                                 perf_header_attr__delete(h_attr);
224                                 h_attr = NULL;
225                         }
226         }
227
228         return h_attr;
229 }
230
231 static void create_counter(struct perf_evsel *evsel, int cpu)
232 {
233         char *filter = evsel->filter;
234         struct perf_event_attr *attr = &evsel->attr;
235         struct perf_header_attr *h_attr;
236         int track = !evsel->idx; /* only the first counter needs these */
237         int thread_index;
238         int ret;
239         struct {
240                 u64 count;
241                 u64 time_enabled;
242                 u64 time_running;
243                 u64 id;
244         } read_data;
245         /*
246          * Check if parse_single_tracepoint_event has already asked for
247          * PERF_SAMPLE_TIME.
248          *
249          * XXX this is kludgy but short term fix for problems introduced by
250          * eac23d1c that broke 'perf script' by having different sample_types
251          * when using multiple tracepoint events when we use a perf binary
252          * that tries to use sample_id_all on an older kernel.
253          *
254          * We need to move counter creation to perf_session, support
255          * different sample_types, etc.
256          */
257         bool time_needed = attr->sample_type & PERF_SAMPLE_TIME;
258
259         attr->read_format       = PERF_FORMAT_TOTAL_TIME_ENABLED |
260                                   PERF_FORMAT_TOTAL_TIME_RUNNING |
261                                   PERF_FORMAT_ID;
262
263         attr->sample_type       |= PERF_SAMPLE_IP | PERF_SAMPLE_TID;
264
265         if (nr_counters > 1)
266                 attr->sample_type |= PERF_SAMPLE_ID;
267
268         /*
269          * We default some events to a 1 default interval. But keep
270          * it a weak assumption overridable by the user.
271          */
272         if (!attr->sample_period || (user_freq != UINT_MAX &&
273                                      user_interval != ULLONG_MAX)) {
274                 if (freq) {
275                         attr->sample_type       |= PERF_SAMPLE_PERIOD;
276                         attr->freq              = 1;
277                         attr->sample_freq       = freq;
278                 } else {
279                         attr->sample_period = default_interval;
280                 }
281         }
282
283         if (no_samples)
284                 attr->sample_freq = 0;
285
286         if (inherit_stat)
287                 attr->inherit_stat = 1;
288
289         if (sample_address) {
290                 attr->sample_type       |= PERF_SAMPLE_ADDR;
291                 attr->mmap_data = track;
292         }
293
294         if (call_graph)
295                 attr->sample_type       |= PERF_SAMPLE_CALLCHAIN;
296
297         if (system_wide)
298                 attr->sample_type       |= PERF_SAMPLE_CPU;
299
300         if (sample_id_all_avail &&
301             (sample_time || system_wide || !no_inherit || cpu_list))
302                 attr->sample_type       |= PERF_SAMPLE_TIME;
303
304         if (raw_samples) {
305                 attr->sample_type       |= PERF_SAMPLE_TIME;
306                 attr->sample_type       |= PERF_SAMPLE_RAW;
307                 attr->sample_type       |= PERF_SAMPLE_CPU;
308         }
309
310         attr->mmap              = track;
311         attr->comm              = track;
312         attr->inherit           = !no_inherit;
313         if (target_pid == -1 && target_tid == -1 && !system_wide) {
314                 attr->disabled = 1;
315                 attr->enable_on_exec = 1;
316         }
317 retry_sample_id:
318         attr->sample_id_all = sample_id_all_avail ? 1 : 0;
319
320         for (thread_index = 0; thread_index < threads->nr; thread_index++) {
321 try_again:
322                 FD(evsel, nr_cpu, thread_index) = sys_perf_event_open(attr, threads->map[thread_index], cpu, group_fd, 0);
323
324                 if (FD(evsel, nr_cpu, thread_index) < 0) {
325                         int err = errno;
326
327                         if (err == EPERM || err == EACCES)
328                                 die("Permission error - are you root?\n"
329                                         "\t Consider tweaking"
330                                         " /proc/sys/kernel/perf_event_paranoid.\n");
331                         else if (err ==  ENODEV && cpu_list) {
332                                 die("No such device - did you specify"
333                                         " an out-of-range profile CPU?\n");
334                         } else if (err == EINVAL && sample_id_all_avail) {
335                                 /*
336                                  * Old kernel, no attr->sample_id_type_all field
337                                  */
338                                 sample_id_all_avail = false;
339                                 if (!sample_time && !raw_samples && !time_needed)
340                                         attr->sample_type &= ~PERF_SAMPLE_TIME;
341
342                                 goto retry_sample_id;
343                         }
344
345                         /*
346                          * If it's cycles then fall back to hrtimer
347                          * based cpu-clock-tick sw counter, which
348                          * is always available even if no PMU support:
349                          */
350                         if (attr->type == PERF_TYPE_HARDWARE
351                                         && attr->config == PERF_COUNT_HW_CPU_CYCLES) {
352
353                                 if (verbose)
354                                         warning(" ... trying to fall back to cpu-clock-ticks\n");
355                                 attr->type = PERF_TYPE_SOFTWARE;
356                                 attr->config = PERF_COUNT_SW_CPU_CLOCK;
357                                 goto try_again;
358                         }
359                         printf("\n");
360                         error("sys_perf_event_open() syscall returned with %d (%s).  /bin/dmesg may provide additional information.\n",
361                               FD(evsel, nr_cpu, thread_index), strerror(err));
362
363 #if defined(__i386__) || defined(__x86_64__)
364                         if (attr->type == PERF_TYPE_HARDWARE && err == EOPNOTSUPP)
365                                 die("No hardware sampling interrupt available."
366                                     " No APIC? If so then you can boot the kernel"
367                                     " with the \"lapic\" boot parameter to"
368                                     " force-enable it.\n");
369 #endif
370
371                         die("No CONFIG_PERF_EVENTS=y kernel support configured?\n");
372                         exit(-1);
373                 }
374
375                 h_attr = get_header_attr(attr, evsel->idx);
376                 if (h_attr == NULL)
377                         die("nomem\n");
378
379                 if (!file_new) {
380                         if (memcmp(&h_attr->attr, attr, sizeof(*attr))) {
381                                 fprintf(stderr, "incompatible append\n");
382                                 exit(-1);
383                         }
384                 }
385
386                 if (read(FD(evsel, nr_cpu, thread_index), &read_data, sizeof(read_data)) == -1) {
387                         perror("Unable to read perf file descriptor");
388                         exit(-1);
389                 }
390
391                 if (perf_header_attr__add_id(h_attr, read_data.id) < 0) {
392                         pr_warning("Not enough memory to add id\n");
393                         exit(-1);
394                 }
395
396                 assert(FD(evsel, nr_cpu, thread_index) >= 0);
397                 fcntl(FD(evsel, nr_cpu, thread_index), F_SETFL, O_NONBLOCK);
398
399                 /*
400                  * First counter acts as the group leader:
401                  */
402                 if (group && group_fd == -1)
403                         group_fd = FD(evsel, nr_cpu, thread_index);
404
405                 if (evsel->idx || thread_index) {
406                         struct perf_evsel *first;
407                         first = list_entry(evsel_list.next, struct perf_evsel, node);
408                         ret = ioctl(FD(evsel, nr_cpu, thread_index),
409                                     PERF_EVENT_IOC_SET_OUTPUT,
410                                     FD(first, nr_cpu, 0));
411                         if (ret) {
412                                 error("failed to set output: %d (%s)\n", errno,
413                                                 strerror(errno));
414                                 exit(-1);
415                         }
416                 } else {
417                         mmap_array[nr_cpu].prev = 0;
418                         mmap_array[nr_cpu].mask = mmap_pages*page_size - 1;
419                         mmap_array[nr_cpu].base = mmap(NULL, (mmap_pages+1)*page_size,
420                                 PROT_READ | PROT_WRITE, MAP_SHARED, FD(evsel, nr_cpu, thread_index), 0);
421                         if (mmap_array[nr_cpu].base == MAP_FAILED) {
422                                 error("failed to mmap with %d (%s)\n", errno, strerror(errno));
423                                 exit(-1);
424                         }
425
426                         event_array[nr_poll].fd = FD(evsel, nr_cpu, thread_index);
427                         event_array[nr_poll].events = POLLIN;
428                         nr_poll++;
429                 }
430
431                 if (filter != NULL) {
432                         ret = ioctl(FD(evsel, nr_cpu, thread_index),
433                                     PERF_EVENT_IOC_SET_FILTER, filter);
434                         if (ret) {
435                                 error("failed to set filter with %d (%s)\n", errno,
436                                                 strerror(errno));
437                                 exit(-1);
438                         }
439                 }
440         }
441
442         if (!sample_type)
443                 sample_type = attr->sample_type;
444 }
445
446 static void open_counters(int cpu)
447 {
448         struct perf_evsel *pos;
449
450         group_fd = -1;
451
452         list_for_each_entry(pos, &evsel_list, node)
453                 create_counter(pos, cpu);
454
455         nr_cpu++;
456 }
457
458 static int process_buildids(void)
459 {
460         u64 size = lseek(output, 0, SEEK_CUR);
461
462         if (size == 0)
463                 return 0;
464
465         session->fd = output;
466         return __perf_session__process_events(session, post_processing_offset,
467                                               size - post_processing_offset,
468                                               size, &build_id__mark_dso_hit_ops);
469 }
470
471 static void atexit_header(void)
472 {
473         if (!pipe_output) {
474                 session->header.data_size += bytes_written;
475
476                 if (!no_buildid)
477                         process_buildids();
478                 perf_header__write(&session->header, output, true);
479                 perf_session__delete(session);
480                 symbol__exit();
481         }
482 }
483
484 static void event__synthesize_guest_os(struct machine *machine, void *data)
485 {
486         int err;
487         struct perf_session *psession = data;
488
489         if (machine__is_host(machine))
490                 return;
491
492         /*
493          *As for guest kernel when processing subcommand record&report,
494          *we arrange module mmap prior to guest kernel mmap and trigger
495          *a preload dso because default guest module symbols are loaded
496          *from guest kallsyms instead of /lib/modules/XXX/XXX. This
497          *method is used to avoid symbol missing when the first addr is
498          *in module instead of in guest kernel.
499          */
500         err = event__synthesize_modules(process_synthesized_event,
501                                         psession, machine);
502         if (err < 0)
503                 pr_err("Couldn't record guest kernel [%d]'s reference"
504                        " relocation symbol.\n", machine->pid);
505
506         /*
507          * We use _stext for guest kernel because guest kernel's /proc/kallsyms
508          * have no _text sometimes.
509          */
510         err = event__synthesize_kernel_mmap(process_synthesized_event,
511                                             psession, machine, "_text");
512         if (err < 0)
513                 err = event__synthesize_kernel_mmap(process_synthesized_event,
514                                                     psession, machine, "_stext");
515         if (err < 0)
516                 pr_err("Couldn't record guest kernel [%d]'s reference"
517                        " relocation symbol.\n", machine->pid);
518 }
519
520 static struct perf_event_header finished_round_event = {
521         .size = sizeof(struct perf_event_header),
522         .type = PERF_RECORD_FINISHED_ROUND,
523 };
524
525 static void mmap_read_all(void)
526 {
527         int i;
528
529         for (i = 0; i < nr_cpu; i++) {
530                 if (mmap_array[i].base)
531                         mmap_read(&mmap_array[i]);
532         }
533
534         if (perf_header__has_feat(&session->header, HEADER_TRACE_INFO))
535                 write_output(&finished_round_event, sizeof(finished_round_event));
536 }
537
538 static int __cmd_record(int argc, const char **argv)
539 {
540         int i;
541         struct stat st;
542         int flags;
543         int err;
544         unsigned long waking = 0;
545         int child_ready_pipe[2], go_pipe[2];
546         const bool forks = argc > 0;
547         char buf;
548         struct machine *machine;
549
550         page_size = sysconf(_SC_PAGE_SIZE);
551
552         atexit(sig_atexit);
553         signal(SIGCHLD, sig_handler);
554         signal(SIGINT, sig_handler);
555         signal(SIGUSR1, sig_handler);
556
557         if (forks && (pipe(child_ready_pipe) < 0 || pipe(go_pipe) < 0)) {
558                 perror("failed to create pipes");
559                 exit(-1);
560         }
561
562         if (!strcmp(output_name, "-"))
563                 pipe_output = 1;
564         else if (!stat(output_name, &st) && st.st_size) {
565                 if (write_mode == WRITE_FORCE) {
566                         char oldname[PATH_MAX];
567                         snprintf(oldname, sizeof(oldname), "%s.old",
568                                  output_name);
569                         unlink(oldname);
570                         rename(output_name, oldname);
571                 }
572         } else if (write_mode == WRITE_APPEND) {
573                 write_mode = WRITE_FORCE;
574         }
575
576         flags = O_CREAT|O_RDWR;
577         if (write_mode == WRITE_APPEND)
578                 file_new = 0;
579         else
580                 flags |= O_TRUNC;
581
582         if (pipe_output)
583                 output = STDOUT_FILENO;
584         else
585                 output = open(output_name, flags, S_IRUSR | S_IWUSR);
586         if (output < 0) {
587                 perror("failed to create output file");
588                 exit(-1);
589         }
590
591         session = perf_session__new(output_name, O_WRONLY,
592                                     write_mode == WRITE_FORCE, false, NULL);
593         if (session == NULL) {
594                 pr_err("Not enough memory for reading perf file header\n");
595                 return -1;
596         }
597
598         if (!no_buildid)
599                 perf_header__set_feat(&session->header, HEADER_BUILD_ID);
600
601         if (!file_new) {
602                 err = perf_header__read(session, output);
603                 if (err < 0)
604                         goto out_delete_session;
605         }
606
607         if (have_tracepoints(&evsel_list))
608                 perf_header__set_feat(&session->header, HEADER_TRACE_INFO);
609
610         /*
611          * perf_session__delete(session) will be called at atexit_header()
612          */
613         atexit(atexit_header);
614
615         if (forks) {
616                 child_pid = fork();
617                 if (child_pid < 0) {
618                         perror("failed to fork");
619                         exit(-1);
620                 }
621
622                 if (!child_pid) {
623                         if (pipe_output)
624                                 dup2(2, 1);
625                         close(child_ready_pipe[0]);
626                         close(go_pipe[1]);
627                         fcntl(go_pipe[0], F_SETFD, FD_CLOEXEC);
628
629                         /*
630                          * Do a dummy execvp to get the PLT entry resolved,
631                          * so we avoid the resolver overhead on the real
632                          * execvp call.
633                          */
634                         execvp("", (char **)argv);
635
636                         /*
637                          * Tell the parent we're ready to go
638                          */
639                         close(child_ready_pipe[1]);
640
641                         /*
642                          * Wait until the parent tells us to go.
643                          */
644                         if (read(go_pipe[0], &buf, 1) == -1)
645                                 perror("unable to read pipe");
646
647                         execvp(argv[0], (char **)argv);
648
649                         perror(argv[0]);
650                         kill(getppid(), SIGUSR1);
651                         exit(-1);
652                 }
653
654                 if (!system_wide && target_tid == -1 && target_pid == -1)
655                         threads->map[0] = child_pid;
656
657                 close(child_ready_pipe[1]);
658                 close(go_pipe[0]);
659                 /*
660                  * wait for child to settle
661                  */
662                 if (read(child_ready_pipe[0], &buf, 1) == -1) {
663                         perror("unable to read pipe");
664                         exit(-1);
665                 }
666                 close(child_ready_pipe[0]);
667         }
668
669         if (!system_wide && no_inherit && !cpu_list) {
670                 open_counters(-1);
671         } else {
672                 for (i = 0; i < cpus->nr; i++)
673                         open_counters(cpus->map[i]);
674         }
675
676         perf_session__set_sample_type(session, sample_type);
677
678         if (pipe_output) {
679                 err = perf_header__write_pipe(output);
680                 if (err < 0)
681                         return err;
682         } else if (file_new) {
683                 err = perf_header__write(&session->header, output, false);
684                 if (err < 0)
685                         return err;
686         }
687
688         post_processing_offset = lseek(output, 0, SEEK_CUR);
689
690         perf_session__set_sample_id_all(session, sample_id_all_avail);
691
692         if (pipe_output) {
693                 err = event__synthesize_attrs(&session->header,
694                                               process_synthesized_event,
695                                               session);
696                 if (err < 0) {
697                         pr_err("Couldn't synthesize attrs.\n");
698                         return err;
699                 }
700
701                 err = event__synthesize_event_types(process_synthesized_event,
702                                                     session);
703                 if (err < 0) {
704                         pr_err("Couldn't synthesize event_types.\n");
705                         return err;
706                 }
707
708                 if (have_tracepoints(&evsel_list)) {
709                         /*
710                          * FIXME err <= 0 here actually means that
711                          * there were no tracepoints so its not really
712                          * an error, just that we don't need to
713                          * synthesize anything.  We really have to
714                          * return this more properly and also
715                          * propagate errors that now are calling die()
716                          */
717                         err = event__synthesize_tracing_data(output, &evsel_list,
718                                                              process_synthesized_event,
719                                                              session);
720                         if (err <= 0) {
721                                 pr_err("Couldn't record tracing data.\n");
722                                 return err;
723                         }
724                         advance_output(err);
725                 }
726         }
727
728         machine = perf_session__find_host_machine(session);
729         if (!machine) {
730                 pr_err("Couldn't find native kernel information.\n");
731                 return -1;
732         }
733
734         err = event__synthesize_kernel_mmap(process_synthesized_event,
735                                             session, machine, "_text");
736         if (err < 0)
737                 err = event__synthesize_kernel_mmap(process_synthesized_event,
738                                                     session, machine, "_stext");
739         if (err < 0)
740                 pr_err("Couldn't record kernel reference relocation symbol\n"
741                        "Symbol resolution may be skewed if relocation was used (e.g. kexec).\n"
742                        "Check /proc/kallsyms permission or run as root.\n");
743
744         err = event__synthesize_modules(process_synthesized_event,
745                                         session, machine);
746         if (err < 0)
747                 pr_err("Couldn't record kernel module information.\n"
748                        "Symbol resolution may be skewed if relocation was used (e.g. kexec).\n"
749                        "Check /proc/modules permission or run as root.\n");
750
751         if (perf_guest)
752                 perf_session__process_machines(session, event__synthesize_guest_os);
753
754         if (!system_wide)
755                 event__synthesize_thread(target_tid, process_synthesized_event,
756                                          session);
757         else
758                 event__synthesize_threads(process_synthesized_event, session);
759
760         if (realtime_prio) {
761                 struct sched_param param;
762
763                 param.sched_priority = realtime_prio;
764                 if (sched_setscheduler(0, SCHED_FIFO, &param)) {
765                         pr_err("Could not set realtime priority.\n");
766                         exit(-1);
767                 }
768         }
769
770         /*
771          * Let the child rip
772          */
773         if (forks)
774                 close(go_pipe[1]);
775
776         for (;;) {
777                 int hits = samples;
778                 int thread;
779
780                 mmap_read_all();
781
782                 if (hits == samples) {
783                         if (done)
784                                 break;
785                         err = poll(event_array, nr_poll, -1);
786                         waking++;
787                 }
788
789                 if (done) {
790                         for (i = 0; i < nr_cpu; i++) {
791                                 struct perf_evsel *pos;
792
793                                 list_for_each_entry(pos, &evsel_list, node) {
794                                         for (thread = 0;
795                                                 thread < threads->nr;
796                                                 thread++)
797                                                 ioctl(FD(pos, i, thread),
798                                                         PERF_EVENT_IOC_DISABLE);
799                                 }
800                         }
801                 }
802         }
803
804         if (quiet || signr == SIGUSR1)
805                 return 0;
806
807         fprintf(stderr, "[ perf record: Woken up %ld times to write data ]\n", waking);
808
809         /*
810          * Approximate RIP event size: 24 bytes.
811          */
812         fprintf(stderr,
813                 "[ perf record: Captured and wrote %.3f MB %s (~%lld samples) ]\n",
814                 (double)bytes_written / 1024.0 / 1024.0,
815                 output_name,
816                 bytes_written / 24);
817
818         return 0;
819
820 out_delete_session:
821         perf_session__delete(session);
822         return err;
823 }
824
825 static const char * const record_usage[] = {
826         "perf record [<options>] [<command>]",
827         "perf record [<options>] -- <command> [<options>]",
828         NULL
829 };
830
831 static bool force, append_file;
832
833 const struct option record_options[] = {
834         OPT_CALLBACK('e', "event", NULL, "event",
835                      "event selector. use 'perf list' to list available events",
836                      parse_events),
837         OPT_CALLBACK(0, "filter", NULL, "filter",
838                      "event filter", parse_filter),
839         OPT_INTEGER('p', "pid", &target_pid,
840                     "record events on existing process id"),
841         OPT_INTEGER('t', "tid", &target_tid,
842                     "record events on existing thread id"),
843         OPT_INTEGER('r', "realtime", &realtime_prio,
844                     "collect data with this RT SCHED_FIFO priority"),
845         OPT_BOOLEAN('R', "raw-samples", &raw_samples,
846                     "collect raw sample records from all opened counters"),
847         OPT_BOOLEAN('a', "all-cpus", &system_wide,
848                             "system-wide collection from all CPUs"),
849         OPT_BOOLEAN('A', "append", &append_file,
850                             "append to the output file to do incremental profiling"),
851         OPT_STRING('C', "cpu", &cpu_list, "cpu",
852                     "list of cpus to monitor"),
853         OPT_BOOLEAN('f', "force", &force,
854                         "overwrite existing data file (deprecated)"),
855         OPT_U64('c', "count", &user_interval, "event period to sample"),
856         OPT_STRING('o', "output", &output_name, "file",
857                     "output file name"),
858         OPT_BOOLEAN('i', "no-inherit", &no_inherit,
859                     "child tasks do not inherit counters"),
860         OPT_UINTEGER('F', "freq", &user_freq, "profile at this frequency"),
861         OPT_UINTEGER('m', "mmap-pages", &mmap_pages, "number of mmap data pages"),
862         OPT_BOOLEAN('g', "call-graph", &call_graph,
863                     "do call-graph (stack chain/backtrace) recording"),
864         OPT_INCR('v', "verbose", &verbose,
865                     "be more verbose (show counter open errors, etc)"),
866         OPT_BOOLEAN('q', "quiet", &quiet, "don't print any message"),
867         OPT_BOOLEAN('s', "stat", &inherit_stat,
868                     "per thread counts"),
869         OPT_BOOLEAN('d', "data", &sample_address,
870                     "Sample addresses"),
871         OPT_BOOLEAN('T', "timestamp", &sample_time, "Sample timestamps"),
872         OPT_BOOLEAN('n', "no-samples", &no_samples,
873                     "don't sample"),
874         OPT_BOOLEAN('N', "no-buildid-cache", &no_buildid_cache,
875                     "do not update the buildid cache"),
876         OPT_BOOLEAN('B', "no-buildid", &no_buildid,
877                     "do not collect buildids in perf.data"),
878         OPT_END()
879 };
880
881 int cmd_record(int argc, const char **argv, const char *prefix __used)
882 {
883         int err = -ENOMEM;
884         struct perf_evsel *pos;
885
886         argc = parse_options(argc, argv, record_options, record_usage,
887                             PARSE_OPT_STOP_AT_NON_OPTION);
888         if (!argc && target_pid == -1 && target_tid == -1 &&
889                 !system_wide && !cpu_list)
890                 usage_with_options(record_usage, record_options);
891
892         if (force && append_file) {
893                 fprintf(stderr, "Can't overwrite and append at the same time."
894                                 " You need to choose between -f and -A");
895                 usage_with_options(record_usage, record_options);
896         } else if (append_file) {
897                 write_mode = WRITE_APPEND;
898         } else {
899                 write_mode = WRITE_FORCE;
900         }
901
902         symbol__init();
903
904         if (no_buildid_cache || no_buildid)
905                 disable_buildid_cache();
906
907         if (list_empty(&evsel_list) && perf_evsel_list__create_default() < 0) {
908                 pr_err("Not enough memory for event selector list\n");
909                 goto out_symbol_exit;
910         }
911
912         if (target_pid != -1)
913                 target_tid = target_pid;
914
915         threads = thread_map__new(target_pid, target_tid);
916         if (threads == NULL) {
917                 pr_err("Problems finding threads of monitor\n");
918                 usage_with_options(record_usage, record_options);
919         }
920
921         cpus = cpu_map__new(cpu_list);
922         if (cpus == NULL) {
923                 perror("failed to parse CPUs map");
924                 return -1;
925         }
926
927         list_for_each_entry(pos, &evsel_list, node) {
928                 if (perf_evsel__alloc_fd(pos, cpus->nr, threads->nr) < 0)
929                         goto out_free_fd;
930         }
931         event_array = malloc((sizeof(struct pollfd) * MAX_NR_CPUS *
932                               MAX_COUNTERS * threads->nr));
933         if (!event_array)
934                 goto out_free_fd;
935
936         if (user_interval != ULLONG_MAX)
937                 default_interval = user_interval;
938         if (user_freq != UINT_MAX)
939                 freq = user_freq;
940
941         /*
942          * User specified count overrides default frequency.
943          */
944         if (default_interval)
945                 freq = 0;
946         else if (freq) {
947                 default_interval = freq;
948         } else {
949                 fprintf(stderr, "frequency and count are zero, aborting\n");
950                 err = -EINVAL;
951                 goto out_free_event_array;
952         }
953
954         err = __cmd_record(argc, argv);
955
956 out_free_event_array:
957         free(event_array);
958 out_free_fd:
959         thread_map__delete(threads);
960         threads = NULL;
961 out_symbol_exit:
962         symbol__exit();
963         return err;
964 }