Merge branch 'perf-fixes-for-linus-2' 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 pid_t                    child_pid                       = -1;
45 static int                      inherit                         = 1;
46 static int                      force                           = 0;
47 static int                      append_file                     = 0;
48 static int                      call_graph                      = 0;
49 static int                      inherit_stat                    = 0;
50 static int                      no_samples                      = 0;
51 static int                      sample_address                  = 0;
52 static int                      multiplex                       = 0;
53 static int                      multiplex_fd                    = -1;
54
55 static long                     samples;
56 static struct timeval           last_read;
57 static struct timeval           this_read;
58
59 static u64                      bytes_written;
60
61 static struct pollfd            event_array[MAX_NR_CPUS * MAX_COUNTERS];
62
63 static int                      nr_poll;
64 static int                      nr_cpu;
65
66 static int                      file_new = 1;
67
68 struct perf_header              *header;
69
70 struct mmap_data {
71         int                     counter;
72         void                    *base;
73         unsigned int            mask;
74         unsigned int            prev;
75 };
76
77 static struct mmap_data         mmap_array[MAX_NR_CPUS][MAX_COUNTERS];
78
79 static unsigned long mmap_read_head(struct mmap_data *md)
80 {
81         struct perf_event_mmap_page *pc = md->base;
82         long head;
83
84         head = pc->data_head;
85         rmb();
86
87         return head;
88 }
89
90 static void mmap_write_tail(struct mmap_data *md, unsigned long tail)
91 {
92         struct perf_event_mmap_page *pc = md->base;
93
94         /*
95          * ensure all reads are done before we write the tail out.
96          */
97         /* mb(); */
98         pc->data_tail = tail;
99 }
100
101 static void write_output(void *buf, size_t size)
102 {
103         while (size) {
104                 int ret = write(output, buf, size);
105
106                 if (ret < 0)
107                         die("failed to write");
108
109                 size -= ret;
110                 buf += ret;
111
112                 bytes_written += ret;
113         }
114 }
115
116 static void mmap_read(struct mmap_data *md)
117 {
118         unsigned int head = mmap_read_head(md);
119         unsigned int old = md->prev;
120         unsigned char *data = md->base + page_size;
121         unsigned long size;
122         void *buf;
123         int diff;
124
125         gettimeofday(&this_read, NULL);
126
127         /*
128          * If we're further behind than half the buffer, there's a chance
129          * the writer will bite our tail and mess up the samples under us.
130          *
131          * If we somehow ended up ahead of the head, we got messed up.
132          *
133          * In either case, truncate and restart at head.
134          */
135         diff = head - old;
136         if (diff < 0) {
137                 struct timeval iv;
138                 unsigned long msecs;
139
140                 timersub(&this_read, &last_read, &iv);
141                 msecs = iv.tv_sec*1000 + iv.tv_usec/1000;
142
143                 fprintf(stderr, "WARNING: failed to keep up with mmap data."
144                                 "  Last read %lu msecs ago.\n", msecs);
145
146                 /*
147                  * head points to a known good entry, start there.
148                  */
149                 old = head;
150         }
151
152         last_read = this_read;
153
154         if (old != head)
155                 samples++;
156
157         size = head - old;
158
159         if ((old & md->mask) + size != (head & md->mask)) {
160                 buf = &data[old & md->mask];
161                 size = md->mask + 1 - (old & md->mask);
162                 old += size;
163
164                 write_output(buf, size);
165         }
166
167         buf = &data[old & md->mask];
168         size = head - old;
169         old += size;
170
171         write_output(buf, size);
172
173         md->prev = old;
174         mmap_write_tail(md, old);
175 }
176
177 static volatile int done = 0;
178 static volatile int signr = -1;
179
180 static void sig_handler(int sig)
181 {
182         done = 1;
183         signr = sig;
184 }
185
186 static void sig_atexit(void)
187 {
188         if (child_pid != -1)
189                 kill(child_pid, SIGTERM);
190
191         if (signr == -1)
192                 return;
193
194         signal(signr, SIG_DFL);
195         kill(getpid(), signr);
196 }
197
198 static pid_t pid_synthesize_comm_event(pid_t pid, int full)
199 {
200         struct comm_event comm_ev;
201         char filename[PATH_MAX];
202         char bf[BUFSIZ];
203         FILE *fp;
204         size_t size = 0;
205         DIR *tasks;
206         struct dirent dirent, *next;
207         pid_t tgid = 0;
208
209         snprintf(filename, sizeof(filename), "/proc/%d/status", pid);
210
211         fp = fopen(filename, "r");
212         if (fp == NULL) {
213                 /*
214                  * We raced with a task exiting - just return:
215                  */
216                 if (verbose)
217                         fprintf(stderr, "couldn't open %s\n", filename);
218                 return 0;
219         }
220
221         memset(&comm_ev, 0, sizeof(comm_ev));
222         while (!comm_ev.comm[0] || !comm_ev.pid) {
223                 if (fgets(bf, sizeof(bf), fp) == NULL)
224                         goto out_failure;
225
226                 if (memcmp(bf, "Name:", 5) == 0) {
227                         char *name = bf + 5;
228                         while (*name && isspace(*name))
229                                 ++name;
230                         size = strlen(name) - 1;
231                         memcpy(comm_ev.comm, name, size++);
232                 } else if (memcmp(bf, "Tgid:", 5) == 0) {
233                         char *tgids = bf + 5;
234                         while (*tgids && isspace(*tgids))
235                                 ++tgids;
236                         tgid = comm_ev.pid = atoi(tgids);
237                 }
238         }
239
240         comm_ev.header.type = PERF_RECORD_COMM;
241         size = ALIGN(size, sizeof(u64));
242         comm_ev.header.size = sizeof(comm_ev) - (sizeof(comm_ev.comm) - size);
243
244         if (!full) {
245                 comm_ev.tid = pid;
246
247                 write_output(&comm_ev, comm_ev.header.size);
248                 goto out_fclose;
249         }
250
251         snprintf(filename, sizeof(filename), "/proc/%d/task", pid);
252
253         tasks = opendir(filename);
254         while (!readdir_r(tasks, &dirent, &next) && next) {
255                 char *end;
256                 pid = strtol(dirent.d_name, &end, 10);
257                 if (*end)
258                         continue;
259
260                 comm_ev.tid = pid;
261
262                 write_output(&comm_ev, comm_ev.header.size);
263         }
264         closedir(tasks);
265
266 out_fclose:
267         fclose(fp);
268         return tgid;
269
270 out_failure:
271         fprintf(stderr, "couldn't get COMM and pgid, malformed %s\n",
272                 filename);
273         exit(EXIT_FAILURE);
274 }
275
276 static void pid_synthesize_mmap_samples(pid_t pid, pid_t tgid)
277 {
278         char filename[PATH_MAX];
279         FILE *fp;
280
281         snprintf(filename, sizeof(filename), "/proc/%d/maps", pid);
282
283         fp = fopen(filename, "r");
284         if (fp == NULL) {
285                 /*
286                  * We raced with a task exiting - just return:
287                  */
288                 if (verbose)
289                         fprintf(stderr, "couldn't open %s\n", filename);
290                 return;
291         }
292         while (1) {
293                 char bf[BUFSIZ], *pbf = bf;
294                 struct mmap_event mmap_ev = {
295                         .header = { .type = PERF_RECORD_MMAP },
296                 };
297                 int n;
298                 size_t size;
299                 if (fgets(bf, sizeof(bf), fp) == NULL)
300                         break;
301
302                 /* 00400000-0040c000 r-xp 00000000 fd:01 41038  /bin/cat */
303                 n = hex2u64(pbf, &mmap_ev.start);
304                 if (n < 0)
305                         continue;
306                 pbf += n + 1;
307                 n = hex2u64(pbf, &mmap_ev.len);
308                 if (n < 0)
309                         continue;
310                 pbf += n + 3;
311                 if (*pbf == 'x') { /* vm_exec */
312                         char *execname = strchr(bf, '/');
313
314                         /* Catch VDSO */
315                         if (execname == NULL)
316                                 execname = strstr(bf, "[vdso]");
317
318                         if (execname == NULL)
319                                 continue;
320
321                         size = strlen(execname);
322                         execname[size - 1] = '\0'; /* Remove \n */
323                         memcpy(mmap_ev.filename, execname, size);
324                         size = ALIGN(size, sizeof(u64));
325                         mmap_ev.len -= mmap_ev.start;
326                         mmap_ev.header.size = (sizeof(mmap_ev) -
327                                                (sizeof(mmap_ev.filename) - size));
328                         mmap_ev.pid = tgid;
329                         mmap_ev.tid = pid;
330
331                         write_output(&mmap_ev, mmap_ev.header.size);
332                 }
333         }
334
335         fclose(fp);
336 }
337
338 static void synthesize_all(void)
339 {
340         DIR *proc;
341         struct dirent dirent, *next;
342
343         proc = opendir("/proc");
344
345         while (!readdir_r(proc, &dirent, &next) && next) {
346                 char *end;
347                 pid_t pid, tgid;
348
349                 pid = strtol(dirent.d_name, &end, 10);
350                 if (*end) /* only interested in proper numerical dirents */
351                         continue;
352
353                 tgid = pid_synthesize_comm_event(pid, 1);
354                 pid_synthesize_mmap_samples(pid, tgid);
355         }
356
357         closedir(proc);
358 }
359
360 static int group_fd;
361
362 static struct perf_header_attr *get_header_attr(struct perf_event_attr *a, int nr)
363 {
364         struct perf_header_attr *h_attr;
365
366         if (nr < header->attrs) {
367                 h_attr = header->attr[nr];
368         } else {
369                 h_attr = perf_header_attr__new(a);
370                 perf_header__add_attr(header, h_attr);
371         }
372
373         return h_attr;
374 }
375
376 static void create_counter(int counter, int cpu, pid_t pid)
377 {
378         struct perf_event_attr *attr = attrs + counter;
379         struct perf_header_attr *h_attr;
380         int track = !counter; /* only the first counter needs these */
381         struct {
382                 u64 count;
383                 u64 time_enabled;
384                 u64 time_running;
385                 u64 id;
386         } read_data;
387
388         attr->read_format       = PERF_FORMAT_TOTAL_TIME_ENABLED |
389                                   PERF_FORMAT_TOTAL_TIME_RUNNING |
390                                   PERF_FORMAT_ID;
391
392         attr->sample_type       |= PERF_SAMPLE_IP | PERF_SAMPLE_TID;
393
394         if (freq) {
395                 attr->sample_type       |= PERF_SAMPLE_PERIOD;
396                 attr->freq              = 1;
397                 attr->sample_freq       = freq;
398         }
399
400         if (no_samples)
401                 attr->sample_freq = 0;
402
403         if (inherit_stat)
404                 attr->inherit_stat = 1;
405
406         if (sample_address)
407                 attr->sample_type       |= PERF_SAMPLE_ADDR;
408
409         if (call_graph)
410                 attr->sample_type       |= PERF_SAMPLE_CALLCHAIN;
411
412         if (raw_samples) {
413                 attr->sample_type       |= PERF_SAMPLE_TIME;
414                 attr->sample_type       |= PERF_SAMPLE_RAW;
415                 attr->sample_type       |= PERF_SAMPLE_CPU;
416         }
417
418         attr->mmap              = track;
419         attr->comm              = track;
420         attr->inherit           = (cpu < 0) && inherit;
421         attr->disabled          = 1;
422
423 try_again:
424         fd[nr_cpu][counter] = sys_perf_event_open(attr, pid, cpu, group_fd, 0);
425
426         if (fd[nr_cpu][counter] < 0) {
427                 int err = errno;
428
429                 if (err == EPERM)
430                         die("Permission error - are you root?\n");
431                 else if (err ==  ENODEV && profile_cpu != -1)
432                         die("No such device - did you specify an out-of-range profile CPU?\n");
433
434                 /*
435                  * If it's cycles then fall back to hrtimer
436                  * based cpu-clock-tick sw counter, which
437                  * is always available even if no PMU support:
438                  */
439                 if (attr->type == PERF_TYPE_HARDWARE
440                         && attr->config == PERF_COUNT_HW_CPU_CYCLES) {
441
442                         if (verbose)
443                                 warning(" ... trying to fall back to cpu-clock-ticks\n");
444                         attr->type = PERF_TYPE_SOFTWARE;
445                         attr->config = PERF_COUNT_SW_CPU_CLOCK;
446                         goto try_again;
447                 }
448                 printf("\n");
449                 error("perfcounter syscall returned with %d (%s)\n",
450                         fd[nr_cpu][counter], strerror(err));
451                 die("No CONFIG_PERF_EVENTS=y kernel support configured?\n");
452                 exit(-1);
453         }
454
455         h_attr = get_header_attr(attr, counter);
456
457         if (!file_new) {
458                 if (memcmp(&h_attr->attr, attr, sizeof(*attr))) {
459                         fprintf(stderr, "incompatible append\n");
460                         exit(-1);
461                 }
462         }
463
464         if (read(fd[nr_cpu][counter], &read_data, sizeof(read_data)) == -1) {
465                 perror("Unable to read perf file descriptor\n");
466                 exit(-1);
467         }
468
469         perf_header_attr__add_id(h_attr, read_data.id);
470
471         assert(fd[nr_cpu][counter] >= 0);
472         fcntl(fd[nr_cpu][counter], F_SETFL, O_NONBLOCK);
473
474         /*
475          * First counter acts as the group leader:
476          */
477         if (group && group_fd == -1)
478                 group_fd = fd[nr_cpu][counter];
479         if (multiplex && multiplex_fd == -1)
480                 multiplex_fd = fd[nr_cpu][counter];
481
482         if (multiplex && fd[nr_cpu][counter] != multiplex_fd) {
483                 int ret;
484
485                 ret = ioctl(fd[nr_cpu][counter], PERF_EVENT_IOC_SET_OUTPUT, multiplex_fd);
486                 assert(ret != -1);
487         } else {
488                 event_array[nr_poll].fd = fd[nr_cpu][counter];
489                 event_array[nr_poll].events = POLLIN;
490                 nr_poll++;
491
492                 mmap_array[nr_cpu][counter].counter = counter;
493                 mmap_array[nr_cpu][counter].prev = 0;
494                 mmap_array[nr_cpu][counter].mask = mmap_pages*page_size - 1;
495                 mmap_array[nr_cpu][counter].base = mmap(NULL, (mmap_pages+1)*page_size,
496                                 PROT_READ|PROT_WRITE, MAP_SHARED, fd[nr_cpu][counter], 0);
497                 if (mmap_array[nr_cpu][counter].base == MAP_FAILED) {
498                         error("failed to mmap with %d (%s)\n", errno, strerror(errno));
499                         exit(-1);
500                 }
501         }
502
503         ioctl(fd[nr_cpu][counter], PERF_EVENT_IOC_ENABLE);
504 }
505
506 static void open_counters(int cpu, pid_t pid)
507 {
508         int counter;
509
510         group_fd = -1;
511         for (counter = 0; counter < nr_counters; counter++)
512                 create_counter(counter, cpu, pid);
513
514         nr_cpu++;
515 }
516
517 static void atexit_header(void)
518 {
519         header->data_size += bytes_written;
520
521         perf_header__write(header, output);
522 }
523
524 static int __cmd_record(int argc, const char **argv)
525 {
526         int i, counter;
527         struct stat st;
528         pid_t pid = 0;
529         int flags;
530         int ret;
531         unsigned long waking = 0;
532
533         page_size = sysconf(_SC_PAGE_SIZE);
534         nr_cpus = sysconf(_SC_NPROCESSORS_ONLN);
535         assert(nr_cpus <= MAX_NR_CPUS);
536         assert(nr_cpus >= 0);
537
538         atexit(sig_atexit);
539         signal(SIGCHLD, sig_handler);
540         signal(SIGINT, sig_handler);
541
542         if (!stat(output_name, &st) && st.st_size) {
543                 if (!force && !append_file) {
544                         fprintf(stderr, "Error, output file %s exists, use -A to append or -f to overwrite.\n",
545                                         output_name);
546                         exit(-1);
547                 }
548         } else {
549                 append_file = 0;
550         }
551
552         flags = O_CREAT|O_RDWR;
553         if (append_file)
554                 file_new = 0;
555         else
556                 flags |= O_TRUNC;
557
558         output = open(output_name, flags, S_IRUSR|S_IWUSR);
559         if (output < 0) {
560                 perror("failed to create output file");
561                 exit(-1);
562         }
563
564         if (!file_new)
565                 header = perf_header__read(output);
566         else
567                 header = perf_header__new();
568
569
570         if (raw_samples) {
571                 read_tracing_data(attrs, nr_counters);
572         } else {
573                 for (i = 0; i < nr_counters; i++) {
574                         if (attrs[i].sample_type & PERF_SAMPLE_RAW) {
575                                 read_tracing_data(attrs, nr_counters);
576                                 break;
577                         }
578                 }
579         }
580         atexit(atexit_header);
581
582         if (!system_wide) {
583                 pid = target_pid;
584                 if (pid == -1)
585                         pid = getpid();
586
587                 open_counters(profile_cpu, pid);
588         } else {
589                 if (profile_cpu != -1) {
590                         open_counters(profile_cpu, target_pid);
591                 } else {
592                         for (i = 0; i < nr_cpus; i++)
593                                 open_counters(i, target_pid);
594                 }
595         }
596
597         if (file_new)
598                 perf_header__write(header, output);
599
600         if (!system_wide) {
601                 pid_t tgid = pid_synthesize_comm_event(pid, 0);
602                 pid_synthesize_mmap_samples(pid, tgid);
603         } else
604                 synthesize_all();
605
606         if (target_pid == -1 && argc) {
607                 pid = fork();
608                 if (pid < 0)
609                         perror("failed to fork");
610
611                 if (!pid) {
612                         if (execvp(argv[0], (char **)argv)) {
613                                 perror(argv[0]);
614                                 exit(-1);
615                         }
616                 }
617
618                 child_pid = pid;
619         }
620
621         if (realtime_prio) {
622                 struct sched_param param;
623
624                 param.sched_priority = realtime_prio;
625                 if (sched_setscheduler(0, SCHED_FIFO, &param)) {
626                         printf("Could not set realtime priority.\n");
627                         exit(-1);
628                 }
629         }
630
631         for (;;) {
632                 int hits = samples;
633
634                 for (i = 0; i < nr_cpu; i++) {
635                         for (counter = 0; counter < nr_counters; counter++) {
636                                 if (mmap_array[i][counter].base)
637                                         mmap_read(&mmap_array[i][counter]);
638                         }
639                 }
640
641                 if (hits == samples) {
642                         if (done)
643                                 break;
644                         ret = poll(event_array, nr_poll, -1);
645                         waking++;
646                 }
647
648                 if (done) {
649                         for (i = 0; i < nr_cpu; i++) {
650                                 for (counter = 0; counter < nr_counters; counter++)
651                                         ioctl(fd[i][counter], PERF_EVENT_IOC_DISABLE);
652                         }
653                 }
654         }
655
656         fprintf(stderr, "[ perf record: Woken up %ld times to write data ]\n", waking);
657
658         /*
659          * Approximate RIP event size: 24 bytes.
660          */
661         fprintf(stderr,
662                 "[ perf record: Captured and wrote %.3f MB %s (~%lld samples) ]\n",
663                 (double)bytes_written / 1024.0 / 1024.0,
664                 output_name,
665                 bytes_written / 24);
666
667         return 0;
668 }
669
670 static const char * const record_usage[] = {
671         "perf record [<options>] [<command>]",
672         "perf record [<options>] -- <command> [<options>]",
673         NULL
674 };
675
676 static const struct option options[] = {
677         OPT_CALLBACK('e', "event", NULL, "event",
678                      "event selector. use 'perf list' to list available events",
679                      parse_events),
680         OPT_INTEGER('p', "pid", &target_pid,
681                     "record events on existing pid"),
682         OPT_INTEGER('r', "realtime", &realtime_prio,
683                     "collect data with this RT SCHED_FIFO priority"),
684         OPT_BOOLEAN('R', "raw-samples", &raw_samples,
685                     "collect raw sample records from all opened counters"),
686         OPT_BOOLEAN('a', "all-cpus", &system_wide,
687                             "system-wide collection from all CPUs"),
688         OPT_BOOLEAN('A', "append", &append_file,
689                             "append to the output file to do incremental profiling"),
690         OPT_INTEGER('C', "profile_cpu", &profile_cpu,
691                             "CPU to profile on"),
692         OPT_BOOLEAN('f', "force", &force,
693                         "overwrite existing data file"),
694         OPT_LONG('c', "count", &default_interval,
695                     "event period to sample"),
696         OPT_STRING('o', "output", &output_name, "file",
697                     "output file name"),
698         OPT_BOOLEAN('i', "inherit", &inherit,
699                     "child tasks inherit counters"),
700         OPT_INTEGER('F', "freq", &freq,
701                     "profile at this frequency"),
702         OPT_INTEGER('m', "mmap-pages", &mmap_pages,
703                     "number of mmap data pages"),
704         OPT_BOOLEAN('g', "call-graph", &call_graph,
705                     "do call-graph (stack chain/backtrace) recording"),
706         OPT_BOOLEAN('v', "verbose", &verbose,
707                     "be more verbose (show counter open errors, etc)"),
708         OPT_BOOLEAN('s', "stat", &inherit_stat,
709                     "per thread counts"),
710         OPT_BOOLEAN('d', "data", &sample_address,
711                     "Sample addresses"),
712         OPT_BOOLEAN('n', "no-samples", &no_samples,
713                     "don't sample"),
714         OPT_BOOLEAN('M', "multiplex", &multiplex,
715                     "multiplex counter output in a single channel"),
716         OPT_END()
717 };
718
719 int cmd_record(int argc, const char **argv, const char *prefix __used)
720 {
721         int counter;
722
723         argc = parse_options(argc, argv, options, record_usage,
724                 PARSE_OPT_STOP_AT_NON_OPTION);
725         if (!argc && target_pid == -1 && !system_wide)
726                 usage_with_options(record_usage, options);
727
728         if (!nr_counters) {
729                 nr_counters     = 1;
730                 attrs[0].type   = PERF_TYPE_HARDWARE;
731                 attrs[0].config = PERF_COUNT_HW_CPU_CYCLES;
732         }
733
734         for (counter = 0; counter < nr_counters; counter++) {
735                 if (attrs[counter].sample_period)
736                         continue;
737
738                 attrs[counter].sample_period = default_interval;
739         }
740
741         return __cmd_record(argc, argv);
742 }