Merge branch 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[linux-2.6.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 #include "builtin.h"
9
10 #include "perf.h"
11
12 #include "util/util.h"
13 #include "util/parse-options.h"
14 #include "util/parse-events.h"
15 #include "util/string.h"
16
17 #include "util/header.h"
18 #include "util/event.h"
19 #include "util/debug.h"
20 #include "util/trace-event.h"
21
22 #include <unistd.h>
23 #include <sched.h>
24
25 #define ALIGN(x, a)             __ALIGN_MASK(x, (typeof(x))(a)-1)
26 #define __ALIGN_MASK(x, mask)   (((x)+(mask))&~(mask))
27
28 static int                      fd[MAX_NR_CPUS][MAX_COUNTERS];
29
30 static long                     default_interval                = 100000;
31
32 static int                      nr_cpus                         = 0;
33 static unsigned int             page_size;
34 static unsigned int             mmap_pages                      = 128;
35 static int                      freq                            = 0;
36 static int                      output;
37 static const char               *output_name                    = "perf.data";
38 static int                      group                           = 0;
39 static unsigned int             realtime_prio                   = 0;
40 static int                      raw_samples                     = 0;
41 static int                      system_wide                     = 0;
42 static int                      profile_cpu                     = -1;
43 static pid_t                    target_pid                      = -1;
44 static int                      inherit                         = 1;
45 static int                      force                           = 0;
46 static int                      append_file                     = 0;
47 static int                      call_graph                      = 0;
48 static int                      inherit_stat                    = 0;
49 static int                      no_samples                      = 0;
50 static int                      sample_address                  = 0;
51 static int                      multiplex                       = 0;
52 static int                      multiplex_fd                    = -1;
53
54 static long                     samples;
55 static struct timeval           last_read;
56 static struct timeval           this_read;
57
58 static u64                      bytes_written;
59
60 static struct pollfd            event_array[MAX_NR_CPUS * MAX_COUNTERS];
61
62 static int                      nr_poll;
63 static int                      nr_cpu;
64
65 static int                      file_new = 1;
66
67 struct perf_header              *header;
68
69 struct mmap_data {
70         int                     counter;
71         void                    *base;
72         unsigned int            mask;
73         unsigned int            prev;
74 };
75
76 static struct mmap_data         mmap_array[MAX_NR_CPUS][MAX_COUNTERS];
77
78 static unsigned long mmap_read_head(struct mmap_data *md)
79 {
80         struct perf_event_mmap_page *pc = md->base;
81         long head;
82
83         head = pc->data_head;
84         rmb();
85
86         return head;
87 }
88
89 static void mmap_write_tail(struct mmap_data *md, unsigned long tail)
90 {
91         struct perf_event_mmap_page *pc = md->base;
92
93         /*
94          * ensure all reads are done before we write the tail out.
95          */
96         /* mb(); */
97         pc->data_tail = tail;
98 }
99
100 static void write_output(void *buf, size_t size)
101 {
102         while (size) {
103                 int ret = write(output, buf, size);
104
105                 if (ret < 0)
106                         die("failed to write");
107
108                 size -= ret;
109                 buf += ret;
110
111                 bytes_written += ret;
112         }
113 }
114
115 static void mmap_read(struct mmap_data *md)
116 {
117         unsigned int head = mmap_read_head(md);
118         unsigned int old = md->prev;
119         unsigned char *data = md->base + page_size;
120         unsigned long size;
121         void *buf;
122         int diff;
123
124         gettimeofday(&this_read, NULL);
125
126         /*
127          * If we're further behind than half the buffer, there's a chance
128          * the writer will bite our tail and mess up the samples under us.
129          *
130          * If we somehow ended up ahead of the head, we got messed up.
131          *
132          * In either case, truncate and restart at head.
133          */
134         diff = head - old;
135         if (diff < 0) {
136                 struct timeval iv;
137                 unsigned long msecs;
138
139                 timersub(&this_read, &last_read, &iv);
140                 msecs = iv.tv_sec*1000 + iv.tv_usec/1000;
141
142                 fprintf(stderr, "WARNING: failed to keep up with mmap data."
143                                 "  Last read %lu msecs ago.\n", msecs);
144
145                 /*
146                  * head points to a known good entry, start there.
147                  */
148                 old = head;
149         }
150
151         last_read = this_read;
152
153         if (old != head)
154                 samples++;
155
156         size = head - old;
157
158         if ((old & md->mask) + size != (head & md->mask)) {
159                 buf = &data[old & md->mask];
160                 size = md->mask + 1 - (old & md->mask);
161                 old += size;
162
163                 write_output(buf, size);
164         }
165
166         buf = &data[old & md->mask];
167         size = head - old;
168         old += size;
169
170         write_output(buf, size);
171
172         md->prev = old;
173         mmap_write_tail(md, old);
174 }
175
176 static volatile int done = 0;
177 static volatile int signr = -1;
178
179 static void sig_handler(int sig)
180 {
181         done = 1;
182         signr = sig;
183 }
184
185 static void sig_atexit(void)
186 {
187         if (signr == -1)
188                 return;
189
190         signal(signr, SIG_DFL);
191         kill(getpid(), signr);
192 }
193
194 static pid_t pid_synthesize_comm_event(pid_t pid, int full)
195 {
196         struct comm_event comm_ev;
197         char filename[PATH_MAX];
198         char bf[BUFSIZ];
199         FILE *fp;
200         size_t size = 0;
201         DIR *tasks;
202         struct dirent dirent, *next;
203         pid_t tgid = 0;
204
205         snprintf(filename, sizeof(filename), "/proc/%d/status", pid);
206
207         fp = fopen(filename, "r");
208         if (fp == NULL) {
209                 /*
210                  * We raced with a task exiting - just return:
211                  */
212                 if (verbose)
213                         fprintf(stderr, "couldn't open %s\n", filename);
214                 return 0;
215         }
216
217         memset(&comm_ev, 0, sizeof(comm_ev));
218         while (!comm_ev.comm[0] || !comm_ev.pid) {
219                 if (fgets(bf, sizeof(bf), fp) == NULL)
220                         goto out_failure;
221
222                 if (memcmp(bf, "Name:", 5) == 0) {
223                         char *name = bf + 5;
224                         while (*name && isspace(*name))
225                                 ++name;
226                         size = strlen(name) - 1;
227                         memcpy(comm_ev.comm, name, size++);
228                 } else if (memcmp(bf, "Tgid:", 5) == 0) {
229                         char *tgids = bf + 5;
230                         while (*tgids && isspace(*tgids))
231                                 ++tgids;
232                         tgid = comm_ev.pid = atoi(tgids);
233                 }
234         }
235
236         comm_ev.header.type = PERF_RECORD_COMM;
237         size = ALIGN(size, sizeof(u64));
238         comm_ev.header.size = sizeof(comm_ev) - (sizeof(comm_ev.comm) - size);
239
240         if (!full) {
241                 comm_ev.tid = pid;
242
243                 write_output(&comm_ev, comm_ev.header.size);
244                 goto out_fclose;
245         }
246
247         snprintf(filename, sizeof(filename), "/proc/%d/task", pid);
248
249         tasks = opendir(filename);
250         while (!readdir_r(tasks, &dirent, &next) && next) {
251                 char *end;
252                 pid = strtol(dirent.d_name, &end, 10);
253                 if (*end)
254                         continue;
255
256                 comm_ev.tid = pid;
257
258                 write_output(&comm_ev, comm_ev.header.size);
259         }
260         closedir(tasks);
261
262 out_fclose:
263         fclose(fp);
264         return tgid;
265
266 out_failure:
267         fprintf(stderr, "couldn't get COMM and pgid, malformed %s\n",
268                 filename);
269         exit(EXIT_FAILURE);
270 }
271
272 static void pid_synthesize_mmap_samples(pid_t pid, pid_t tgid)
273 {
274         char filename[PATH_MAX];
275         FILE *fp;
276
277         snprintf(filename, sizeof(filename), "/proc/%d/maps", pid);
278
279         fp = fopen(filename, "r");
280         if (fp == NULL) {
281                 /*
282                  * We raced with a task exiting - just return:
283                  */
284                 if (verbose)
285                         fprintf(stderr, "couldn't open %s\n", filename);
286                 return;
287         }
288         while (1) {
289                 char bf[BUFSIZ], *pbf = bf;
290                 struct mmap_event mmap_ev = {
291                         .header = { .type = PERF_RECORD_MMAP },
292                 };
293                 int n;
294                 size_t size;
295                 if (fgets(bf, sizeof(bf), fp) == NULL)
296                         break;
297
298                 /* 00400000-0040c000 r-xp 00000000 fd:01 41038  /bin/cat */
299                 n = hex2u64(pbf, &mmap_ev.start);
300                 if (n < 0)
301                         continue;
302                 pbf += n + 1;
303                 n = hex2u64(pbf, &mmap_ev.len);
304                 if (n < 0)
305                         continue;
306                 pbf += n + 3;
307                 if (*pbf == 'x') { /* vm_exec */
308                         char *execname = strchr(bf, '/');
309
310                         /* Catch VDSO */
311                         if (execname == NULL)
312                                 execname = strstr(bf, "[vdso]");
313
314                         if (execname == NULL)
315                                 continue;
316
317                         size = strlen(execname);
318                         execname[size - 1] = '\0'; /* Remove \n */
319                         memcpy(mmap_ev.filename, execname, size);
320                         size = ALIGN(size, sizeof(u64));
321                         mmap_ev.len -= mmap_ev.start;
322                         mmap_ev.header.size = (sizeof(mmap_ev) -
323                                                (sizeof(mmap_ev.filename) - size));
324                         mmap_ev.pid = tgid;
325                         mmap_ev.tid = pid;
326
327                         write_output(&mmap_ev, mmap_ev.header.size);
328                 }
329         }
330
331         fclose(fp);
332 }
333
334 static void synthesize_all(void)
335 {
336         DIR *proc;
337         struct dirent dirent, *next;
338
339         proc = opendir("/proc");
340
341         while (!readdir_r(proc, &dirent, &next) && next) {
342                 char *end;
343                 pid_t pid, tgid;
344
345                 pid = strtol(dirent.d_name, &end, 10);
346                 if (*end) /* only interested in proper numerical dirents */
347                         continue;
348
349                 tgid = pid_synthesize_comm_event(pid, 1);
350                 pid_synthesize_mmap_samples(pid, tgid);
351         }
352
353         closedir(proc);
354 }
355
356 static int group_fd;
357
358 static struct perf_header_attr *get_header_attr(struct perf_event_attr *a, int nr)
359 {
360         struct perf_header_attr *h_attr;
361
362         if (nr < header->attrs) {
363                 h_attr = header->attr[nr];
364         } else {
365                 h_attr = perf_header_attr__new(a);
366                 perf_header__add_attr(header, h_attr);
367         }
368
369         return h_attr;
370 }
371
372 static void create_counter(int counter, int cpu, pid_t pid)
373 {
374         struct perf_event_attr *attr = attrs + counter;
375         struct perf_header_attr *h_attr;
376         int track = !counter; /* only the first counter needs these */
377         struct {
378                 u64 count;
379                 u64 time_enabled;
380                 u64 time_running;
381                 u64 id;
382         } read_data;
383
384         attr->read_format       = PERF_FORMAT_TOTAL_TIME_ENABLED |
385                                   PERF_FORMAT_TOTAL_TIME_RUNNING |
386                                   PERF_FORMAT_ID;
387
388         attr->sample_type       |= PERF_SAMPLE_IP | PERF_SAMPLE_TID;
389
390         if (freq) {
391                 attr->sample_type       |= PERF_SAMPLE_PERIOD;
392                 attr->freq              = 1;
393                 attr->sample_freq       = freq;
394         }
395
396         if (no_samples)
397                 attr->sample_freq = 0;
398
399         if (inherit_stat)
400                 attr->inherit_stat = 1;
401
402         if (sample_address)
403                 attr->sample_type       |= PERF_SAMPLE_ADDR;
404
405         if (call_graph)
406                 attr->sample_type       |= PERF_SAMPLE_CALLCHAIN;
407
408         if (raw_samples) {
409                 attr->sample_type       |= PERF_SAMPLE_TIME;
410                 attr->sample_type       |= PERF_SAMPLE_RAW;
411                 attr->sample_type       |= PERF_SAMPLE_CPU;
412         }
413
414         attr->mmap              = track;
415         attr->comm              = track;
416         attr->inherit           = (cpu < 0) && inherit;
417         attr->disabled          = 1;
418
419 try_again:
420         fd[nr_cpu][counter] = sys_perf_event_open(attr, pid, cpu, group_fd, 0);
421
422         if (fd[nr_cpu][counter] < 0) {
423                 int err = errno;
424
425                 if (err == EPERM)
426                         die("Permission error - are you root?\n");
427                 else if (err ==  ENODEV && profile_cpu != -1)
428                         die("No such device - did you specify an out-of-range profile CPU?\n");
429
430                 /*
431                  * If it's cycles then fall back to hrtimer
432                  * based cpu-clock-tick sw counter, which
433                  * is always available even if no PMU support:
434                  */
435                 if (attr->type == PERF_TYPE_HARDWARE
436                         && attr->config == PERF_COUNT_HW_CPU_CYCLES) {
437
438                         if (verbose)
439                                 warning(" ... trying to fall back to cpu-clock-ticks\n");
440                         attr->type = PERF_TYPE_SOFTWARE;
441                         attr->config = PERF_COUNT_SW_CPU_CLOCK;
442                         goto try_again;
443                 }
444                 printf("\n");
445                 error("perfcounter syscall returned with %d (%s)\n",
446                         fd[nr_cpu][counter], strerror(err));
447                 die("No CONFIG_PERF_EVENTS=y kernel support configured?\n");
448                 exit(-1);
449         }
450
451         h_attr = get_header_attr(attr, counter);
452
453         if (!file_new) {
454                 if (memcmp(&h_attr->attr, attr, sizeof(*attr))) {
455                         fprintf(stderr, "incompatible append\n");
456                         exit(-1);
457                 }
458         }
459
460         if (read(fd[nr_cpu][counter], &read_data, sizeof(read_data)) == -1) {
461                 perror("Unable to read perf file descriptor\n");
462                 exit(-1);
463         }
464
465         perf_header_attr__add_id(h_attr, read_data.id);
466
467         assert(fd[nr_cpu][counter] >= 0);
468         fcntl(fd[nr_cpu][counter], F_SETFL, O_NONBLOCK);
469
470         /*
471          * First counter acts as the group leader:
472          */
473         if (group && group_fd == -1)
474                 group_fd = fd[nr_cpu][counter];
475         if (multiplex && multiplex_fd == -1)
476                 multiplex_fd = fd[nr_cpu][counter];
477
478         if (multiplex && fd[nr_cpu][counter] != multiplex_fd) {
479                 int ret;
480
481                 ret = ioctl(fd[nr_cpu][counter], PERF_EVENT_IOC_SET_OUTPUT, multiplex_fd);
482                 assert(ret != -1);
483         } else {
484                 event_array[nr_poll].fd = fd[nr_cpu][counter];
485                 event_array[nr_poll].events = POLLIN;
486                 nr_poll++;
487
488                 mmap_array[nr_cpu][counter].counter = counter;
489                 mmap_array[nr_cpu][counter].prev = 0;
490                 mmap_array[nr_cpu][counter].mask = mmap_pages*page_size - 1;
491                 mmap_array[nr_cpu][counter].base = mmap(NULL, (mmap_pages+1)*page_size,
492                                 PROT_READ|PROT_WRITE, MAP_SHARED, fd[nr_cpu][counter], 0);
493                 if (mmap_array[nr_cpu][counter].base == MAP_FAILED) {
494                         error("failed to mmap with %d (%s)\n", errno, strerror(errno));
495                         exit(-1);
496                 }
497         }
498
499         ioctl(fd[nr_cpu][counter], PERF_EVENT_IOC_ENABLE);
500 }
501
502 static void open_counters(int cpu, pid_t pid)
503 {
504         int counter;
505
506         group_fd = -1;
507         for (counter = 0; counter < nr_counters; counter++)
508                 create_counter(counter, cpu, pid);
509
510         nr_cpu++;
511 }
512
513 static void atexit_header(void)
514 {
515         header->data_size += bytes_written;
516
517         perf_header__write(header, output);
518 }
519
520 static int __cmd_record(int argc, const char **argv)
521 {
522         int i, counter;
523         struct stat st;
524         pid_t pid = 0;
525         int flags;
526         int ret;
527         unsigned long waking = 0;
528
529         page_size = sysconf(_SC_PAGE_SIZE);
530         nr_cpus = sysconf(_SC_NPROCESSORS_ONLN);
531         assert(nr_cpus <= MAX_NR_CPUS);
532         assert(nr_cpus >= 0);
533
534         atexit(sig_atexit);
535         signal(SIGCHLD, sig_handler);
536         signal(SIGINT, sig_handler);
537
538         if (!stat(output_name, &st) && st.st_size) {
539                 if (!force && !append_file) {
540                         fprintf(stderr, "Error, output file %s exists, use -A to append or -f to overwrite.\n",
541                                         output_name);
542                         exit(-1);
543                 }
544         } else {
545                 append_file = 0;
546         }
547
548         flags = O_CREAT|O_RDWR;
549         if (append_file)
550                 file_new = 0;
551         else
552                 flags |= O_TRUNC;
553
554         output = open(output_name, flags, S_IRUSR|S_IWUSR);
555         if (output < 0) {
556                 perror("failed to create output file");
557                 exit(-1);
558         }
559
560         if (!file_new)
561                 header = perf_header__read(output);
562         else
563                 header = perf_header__new();
564
565
566         if (raw_samples) {
567                 read_tracing_data(attrs, nr_counters);
568         } else {
569                 for (i = 0; i < nr_counters; i++) {
570                         if (attrs[i].sample_type & PERF_SAMPLE_RAW) {
571                                 read_tracing_data(attrs, nr_counters);
572                                 break;
573                         }
574                 }
575         }
576         atexit(atexit_header);
577
578         if (!system_wide) {
579                 pid = target_pid;
580                 if (pid == -1)
581                         pid = getpid();
582
583                 open_counters(profile_cpu, pid);
584         } else {
585                 if (profile_cpu != -1) {
586                         open_counters(profile_cpu, target_pid);
587                 } else {
588                         for (i = 0; i < nr_cpus; i++)
589                                 open_counters(i, target_pid);
590                 }
591         }
592
593         if (file_new)
594                 perf_header__write(header, output);
595
596         if (!system_wide) {
597                 pid_t tgid = pid_synthesize_comm_event(pid, 0);
598                 pid_synthesize_mmap_samples(pid, tgid);
599         } else
600                 synthesize_all();
601
602         if (target_pid == -1 && argc) {
603                 pid = fork();
604                 if (pid < 0)
605                         perror("failed to fork");
606
607                 if (!pid) {
608                         if (execvp(argv[0], (char **)argv)) {
609                                 perror(argv[0]);
610                                 exit(-1);
611                         }
612                 }
613         }
614
615         if (realtime_prio) {
616                 struct sched_param param;
617
618                 param.sched_priority = realtime_prio;
619                 if (sched_setscheduler(0, SCHED_FIFO, &param)) {
620                         printf("Could not set realtime priority.\n");
621                         exit(-1);
622                 }
623         }
624
625         for (;;) {
626                 int hits = samples;
627
628                 for (i = 0; i < nr_cpu; i++) {
629                         for (counter = 0; counter < nr_counters; counter++) {
630                                 if (mmap_array[i][counter].base)
631                                         mmap_read(&mmap_array[i][counter]);
632                         }
633                 }
634
635                 if (hits == samples) {
636                         if (done)
637                                 break;
638                         ret = poll(event_array, nr_poll, -1);
639                         waking++;
640                 }
641
642                 if (done) {
643                         for (i = 0; i < nr_cpu; i++) {
644                                 for (counter = 0; counter < nr_counters; counter++)
645                                         ioctl(fd[i][counter], PERF_EVENT_IOC_DISABLE);
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_INTEGER('p', "pid", &target_pid,
675                     "record events on existing pid"),
676         OPT_INTEGER('r', "realtime", &realtime_prio,
677                     "collect data with this RT SCHED_FIFO priority"),
678         OPT_BOOLEAN('R', "raw-samples", &raw_samples,
679                     "collect raw sample records from all opened counters"),
680         OPT_BOOLEAN('a', "all-cpus", &system_wide,
681                             "system-wide collection from all CPUs"),
682         OPT_BOOLEAN('A', "append", &append_file,
683                             "append to the output file to do incremental profiling"),
684         OPT_INTEGER('C', "profile_cpu", &profile_cpu,
685                             "CPU to profile on"),
686         OPT_BOOLEAN('f', "force", &force,
687                         "overwrite existing data file"),
688         OPT_LONG('c', "count", &default_interval,
689                     "event period to sample"),
690         OPT_STRING('o', "output", &output_name, "file",
691                     "output file name"),
692         OPT_BOOLEAN('i', "inherit", &inherit,
693                     "child tasks inherit counters"),
694         OPT_INTEGER('F', "freq", &freq,
695                     "profile at this frequency"),
696         OPT_INTEGER('m', "mmap-pages", &mmap_pages,
697                     "number of mmap data pages"),
698         OPT_BOOLEAN('g', "call-graph", &call_graph,
699                     "do call-graph (stack chain/backtrace) recording"),
700         OPT_BOOLEAN('v', "verbose", &verbose,
701                     "be more verbose (show counter open errors, etc)"),
702         OPT_BOOLEAN('s', "stat", &inherit_stat,
703                     "per thread counts"),
704         OPT_BOOLEAN('d', "data", &sample_address,
705                     "Sample addresses"),
706         OPT_BOOLEAN('n', "no-samples", &no_samples,
707                     "don't sample"),
708         OPT_BOOLEAN('M', "multiplex", &multiplex,
709                     "multiplex counter output in a single channel"),
710         OPT_END()
711 };
712
713 int cmd_record(int argc, const char **argv, const char *prefix __used)
714 {
715         int counter;
716
717         argc = parse_options(argc, argv, options, record_usage,
718                 PARSE_OPT_STOP_AT_NON_OPTION);
719         if (!argc && target_pid == -1 && !system_wide)
720                 usage_with_options(record_usage, options);
721
722         if (!nr_counters) {
723                 nr_counters     = 1;
724                 attrs[0].type   = PERF_TYPE_HARDWARE;
725                 attrs[0].config = PERF_COUNT_HW_CPU_CYCLES;
726         }
727
728         for (counter = 0; counter < nr_counters; counter++) {
729                 if (attrs[counter].sample_period)
730                         continue;
731
732                 attrs[counter].sample_period = default_interval;
733         }
734
735         return __cmd_record(argc, argv);
736 }