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perf_counter: Use rb_tree for symhists and threads in report
[mv-sheeva.git] / Documentation / perf_counter / builtin-report.c
1 #define _GNU_SOURCE
2 #include <sys/types.h>
3 #include <sys/stat.h>
4 #include <sys/time.h>
5 #include <unistd.h>
6 #include <stdint.h>
7 #include <stdbool.h>
8 #include <stdlib.h>
9 #include <string.h>
10 #include <limits.h>
11 #include <gelf.h>
12 #include <elf.h>
13 #include <libelf.h>
14 #include <fcntl.h>
15 #include <stdio.h>
16 #include <errno.h>
17 #include <ctype.h>
18 #include <time.h>
19 #include <getopt.h>
20 #include <assert.h>
21 #include <search.h>
22
23 #include <sys/ioctl.h>
24 #include <sys/poll.h>
25 #include <sys/prctl.h>
26 #include <sys/wait.h>
27 #include <sys/mman.h>
28 #include <sys/types.h>
29 #include <sys/stat.h>
30
31 #include <linux/unistd.h>
32 #include <linux/types.h>
33
34 #include "../../include/linux/perf_counter.h"
35 #include "util/list.h"
36 #include "util/rbtree.h"
37
38 #define SHOW_KERNEL     1
39 #define SHOW_USER       2
40 #define SHOW_HV         4
41
42 static char             const *input_name = "output.perf";
43 static int              input;
44 static int              show_mask = SHOW_KERNEL | SHOW_USER | SHOW_HV;
45
46 static unsigned long    page_size;
47 static unsigned long    mmap_window = 32;
48
49 static const char *perf_event_names[] = {
50         [PERF_EVENT_MMAP]   = " PERF_EVENT_MMAP",
51         [PERF_EVENT_MUNMAP] = " PERF_EVENT_MUNMAP",
52         [PERF_EVENT_COMM]   = " PERF_EVENT_COMM",
53 };
54
55 struct ip_event {
56         struct perf_event_header header;
57         __u64 ip;
58         __u32 pid, tid;
59 };
60 struct mmap_event {
61         struct perf_event_header header;
62         __u32 pid, tid;
63         __u64 start;
64         __u64 len;
65         __u64 pgoff;
66         char filename[PATH_MAX];
67 };
68 struct comm_event {
69         struct perf_event_header header;
70         __u32 pid,tid;
71         char comm[16];
72 };
73
74 typedef union event_union {
75         struct perf_event_header header;
76         struct ip_event ip;
77         struct mmap_event mmap;
78         struct comm_event comm;
79 } event_t;
80
81 struct section {
82         struct list_head node;
83         uint64_t         start;
84         uint64_t         end;
85         uint64_t         offset;
86         char             name[0];
87 };
88
89 static struct section *section__new(uint64_t start, uint64_t size,
90                                     uint64_t offset, char *name)
91 {
92         struct section *self = malloc(sizeof(*self) + strlen(name) + 1);
93
94         if (self != NULL) {
95                 self->start  = start;
96                 self->end    = start + size;
97                 self->offset = offset;
98                 strcpy(self->name, name);
99         }
100
101         return self;
102 }
103
104 static void section__delete(struct section *self)
105 {
106         free(self);
107 }
108
109 struct symbol {
110         struct rb_node rb_node;
111         uint64_t       start;
112         uint64_t       end;
113         char           name[0];
114 };
115
116 static struct symbol *symbol__new(uint64_t start, uint64_t len, const char *name)
117 {
118         struct symbol *self = malloc(sizeof(*self) + strlen(name) + 1);
119
120         if (self != NULL) {
121                 self->start = start;
122                 self->end   = start + len;
123                 strcpy(self->name, name);
124         }
125
126         return self;
127 }
128
129 static void symbol__delete(struct symbol *self)
130 {
131         free(self);
132 }
133
134 static size_t symbol__fprintf(struct symbol *self, FILE *fp)
135 {
136         return fprintf(fp, " %lx-%lx %s\n",
137                        self->start, self->end, self->name);
138 }
139
140 struct dso {
141         struct list_head node;
142         struct list_head sections;
143         struct rb_root   syms;
144         char             name[0];
145 };
146
147 static struct dso *dso__new(const char *name)
148 {
149         struct dso *self = malloc(sizeof(*self) + strlen(name) + 1);
150
151         if (self != NULL) {
152                 strcpy(self->name, name);
153                 INIT_LIST_HEAD(&self->sections);
154                 self->syms = RB_ROOT;
155         }
156
157         return self;
158 }
159
160 static void dso__delete_sections(struct dso *self)
161 {
162         struct section *pos, *n;
163
164         list_for_each_entry_safe(pos, n, &self->sections, node)
165                 section__delete(pos);
166 }
167
168 static void dso__delete_symbols(struct dso *self)
169 {
170         struct symbol *pos;
171         struct rb_node *next = rb_first(&self->syms);
172
173         while (next) {
174                 pos = rb_entry(next, struct symbol, rb_node);
175                 next = rb_next(&pos->rb_node);
176                 symbol__delete(pos);
177         }
178 }
179
180 static void dso__delete(struct dso *self)
181 {
182         dso__delete_sections(self);
183         dso__delete_symbols(self);
184         free(self);
185 }
186
187 static void dso__insert_symbol(struct dso *self, struct symbol *sym)
188 {
189         struct rb_node **p = &self->syms.rb_node;
190         struct rb_node *parent = NULL;
191         const uint64_t ip = sym->start;
192         struct symbol *s;
193
194         while (*p != NULL) {
195                 parent = *p;
196                 s = rb_entry(parent, struct symbol, rb_node);
197                 if (ip < s->start)
198                         p = &(*p)->rb_left;
199                 else
200                         p = &(*p)->rb_right;
201         }
202         rb_link_node(&sym->rb_node, parent, p);
203         rb_insert_color(&sym->rb_node, &self->syms);
204 }
205
206 static struct symbol *dso__find_symbol(struct dso *self, uint64_t ip)
207 {
208         if (self == NULL)
209                 return NULL;
210
211         struct rb_node *n = self->syms.rb_node;
212
213         while (n) {
214                 struct symbol *s = rb_entry(n, struct symbol, rb_node);
215
216                 if (ip < s->start)
217                         n = n->rb_left;
218                 else if (ip > s->end)
219                         n = n->rb_right;
220                 else
221                         return s;
222         }
223
224         return NULL;
225 }
226
227 /**
228  * elf_symtab__for_each_symbol - iterate thru all the symbols
229  *
230  * @self: struct elf_symtab instance to iterate
231  * @index: uint32_t index
232  * @sym: GElf_Sym iterator
233  */
234 #define elf_symtab__for_each_symbol(syms, nr_syms, index, sym) \
235         for (index = 0, gelf_getsym(syms, index, &sym);\
236              index < nr_syms; \
237              index++, gelf_getsym(syms, index, &sym))
238
239 static inline uint8_t elf_sym__type(const GElf_Sym *sym)
240 {
241         return GELF_ST_TYPE(sym->st_info);
242 }
243
244 static inline bool elf_sym__is_function(const GElf_Sym *sym)
245 {
246         return elf_sym__type(sym) == STT_FUNC &&
247                sym->st_name != 0 &&
248                sym->st_shndx != SHN_UNDEF;
249 }
250
251 static inline const char *elf_sym__name(const GElf_Sym *sym,
252                                         const Elf_Data *symstrs)
253 {
254         return symstrs->d_buf + sym->st_name;
255 }
256
257 static Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep,
258                                     GElf_Shdr *shp, const char *name,
259                                     size_t *index)
260 {
261         Elf_Scn *sec = NULL;
262         size_t cnt = 1;
263
264         while ((sec = elf_nextscn(elf, sec)) != NULL) {
265                 char *str;
266
267                 gelf_getshdr(sec, shp);
268                 str = elf_strptr(elf, ep->e_shstrndx, shp->sh_name);
269                 if (!strcmp(name, str)) {
270                         if (index)
271                                 *index = cnt;
272                         break;
273                 }
274                 ++cnt;
275         }
276
277         return sec;
278 }
279
280 static int dso__load(struct dso *self)
281 {
282         int fd = open(self->name, O_RDONLY), err = -1;
283
284         if (fd == -1)
285                 return -1;
286
287         Elf *elf = elf_begin(fd, ELF_C_READ_MMAP, NULL);
288         if (elf == NULL) {
289                 fprintf(stderr, "%s: cannot read %s ELF file.\n",
290                         __func__, self->name);
291                 goto out_close;
292         }
293
294         GElf_Ehdr ehdr;
295         if (gelf_getehdr(elf, &ehdr) == NULL) {
296                 fprintf(stderr, "%s: cannot get elf header.\n", __func__);
297                 goto out_elf_end;
298         }
299
300         GElf_Shdr shdr;
301         Elf_Scn *sec = elf_section_by_name(elf, &ehdr, &shdr, ".symtab", NULL);
302         if (sec == NULL)
303                 sec = elf_section_by_name(elf, &ehdr, &shdr, ".dynsym", NULL);
304
305         if (sec == NULL)
306                 goto out_elf_end;
307
308         if (gelf_getshdr(sec, &shdr) == NULL)
309                 goto out_elf_end;
310
311         Elf_Data *syms = elf_getdata(sec, NULL);
312         if (syms == NULL)
313                 goto out_elf_end;
314
315         sec = elf_getscn(elf, shdr.sh_link);
316         if (sec == NULL)
317                 goto out_elf_end;
318
319         Elf_Data *symstrs = elf_getdata(sec, NULL);
320         if (symstrs == NULL)
321                 goto out_elf_end;
322
323         const uint32_t nr_syms = shdr.sh_size / shdr.sh_entsize;
324
325         GElf_Sym sym;
326         uint32_t index;
327         elf_symtab__for_each_symbol(syms, nr_syms, index, sym) {
328                 if (!elf_sym__is_function(&sym))
329                         continue;
330                 struct symbol *f = symbol__new(sym.st_value, sym.st_size,
331                                                elf_sym__name(&sym, symstrs));
332                 if (f == NULL)
333                         goto out_elf_end;
334
335                 dso__insert_symbol(self, f);
336         }
337
338         err = 0;
339 out_elf_end:
340         elf_end(elf);
341 out_close:
342         close(fd);
343         return err;
344 }
345
346 static size_t dso__fprintf(struct dso *self, FILE *fp)
347 {
348         size_t ret = fprintf(fp, "dso: %s\n", self->name);
349
350         struct rb_node *nd;
351         for (nd = rb_first(&self->syms); nd; nd = rb_next(nd)) {
352                 struct symbol *pos = rb_entry(nd, struct symbol, rb_node);
353                 ret += symbol__fprintf(pos, fp);
354         }
355
356         return ret;
357 }
358
359 static LIST_HEAD(dsos);
360 static struct dso *kernel_dso;
361
362 static void dsos__add(struct dso *dso)
363 {
364         list_add_tail(&dso->node, &dsos);
365 }
366
367 static struct dso *dsos__find(const char *name)
368 {
369         struct dso *pos;
370
371         list_for_each_entry(pos, &dsos, node)
372                 if (strcmp(pos->name, name) == 0)
373                         return pos;
374         return NULL;
375 }
376
377 static struct dso *dsos__findnew(const char *name)
378 {
379         struct dso *dso = dsos__find(name);
380
381         if (dso == NULL) {
382                 dso = dso__new(name);
383                 if (dso != NULL && dso__load(dso) < 0)
384                         goto out_delete_dso;
385
386                 dsos__add(dso);
387         }
388
389         return dso;
390
391 out_delete_dso:
392         dso__delete(dso);
393         return NULL;
394 }
395
396 static void dsos__fprintf(FILE *fp)
397 {
398         struct dso *pos;
399
400         list_for_each_entry(pos, &dsos, node)
401                 dso__fprintf(pos, fp);
402 }
403
404 static int load_kallsyms(void)
405 {
406         kernel_dso = dso__new("[kernel]");
407         if (kernel_dso == NULL)
408                 return -1;
409
410         FILE *file = fopen("/proc/kallsyms", "r");
411
412         if (file == NULL)
413                 goto out_delete_dso;
414
415         char *line = NULL;
416         size_t n;
417
418         while (!feof(file)) {
419                 unsigned long long start;
420                 char c, symbf[4096];
421
422                 if (getline(&line, &n, file) < 0)
423                         break;
424
425                 if (!line)
426                         goto out_delete_dso;
427
428                 if (sscanf(line, "%llx %c %s", &start, &c, symbf) == 3) {
429                         struct symbol *sym = symbol__new(start, 0x1000000, symbf);
430
431                         if (sym == NULL)
432                                 goto out_delete_dso;
433
434                         dso__insert_symbol(kernel_dso, sym);
435                 }
436         }
437
438         dsos__add(kernel_dso);
439         free(line);
440         fclose(file);
441         return 0;
442
443 out_delete_dso:
444         dso__delete(kernel_dso);
445         return -1;
446 }
447
448 struct map {
449         struct list_head node;
450         uint64_t         start;
451         uint64_t         end;
452         uint64_t         pgoff;
453         struct dso       *dso;
454 };
455
456 static struct map *map__new(struct mmap_event *event)
457 {
458         struct map *self = malloc(sizeof(*self));
459
460         if (self != NULL) {
461                 self->start = event->start;
462                 self->end   = event->start + event->len;
463                 self->pgoff = event->pgoff;
464
465                 self->dso = dsos__findnew(event->filename);
466                 if (self->dso == NULL)
467                         goto out_delete;
468         }
469         return self;
470 out_delete:
471         free(self);
472         return NULL;
473 }
474
475 static size_t map__fprintf(struct map *self, FILE *fp)
476 {
477         return fprintf(fp, " %lx-%lx %lx %s\n",
478                        self->start, self->end, self->pgoff, self->dso->name);
479 }
480
481 struct symhist {
482         struct rb_node   rb_node;
483         struct dso       *dso;
484         struct symbol    *sym;
485         uint64_t         ip;
486         uint32_t         count;
487         char             level;
488 };
489
490 static struct symhist *symhist__new(struct symbol *sym, uint64_t ip,
491                                     struct dso *dso, char level)
492 {
493         struct symhist *self = malloc(sizeof(*self));
494
495         if (self != NULL) {
496                 self->sym   = sym;
497                 self->ip    = ip;
498                 self->dso   = dso;
499                 self->level = level;
500                 self->count = 1;
501         }
502
503         return self;
504 }
505
506 static void symhist__delete(struct symhist *self)
507 {
508         free(self);
509 }
510
511 static void symhist__inc(struct symhist *self)
512 {
513         ++self->count;
514 }
515
516 static size_t symhist__fprintf(struct symhist *self, FILE *fp)
517 {
518         size_t ret = fprintf(fp, "%#llx [%c] ", (unsigned long long)self->ip, self->level);
519
520         if (self->level != '.')
521                 ret += fprintf(fp, "%s", self->sym->name);
522         else
523                 ret += fprintf(fp, "%s: %s",
524                                self->dso ? self->dso->name : "<unknown",
525                                self->sym ? self->sym->name : "<unknown>");
526         return ret + fprintf(fp, ": %u\n", self->count);
527 }
528
529 struct thread {
530         struct rb_node   rb_node;
531         struct list_head maps;
532         struct rb_root   symhists;
533         pid_t            pid;
534         char             *comm;
535 };
536
537 static struct thread *thread__new(pid_t pid)
538 {
539         struct thread *self = malloc(sizeof(*self));
540
541         if (self != NULL) {
542                 self->pid = pid;
543                 self->comm = NULL;
544                 INIT_LIST_HEAD(&self->maps);
545                 self->symhists = RB_ROOT;
546         }
547
548         return self;
549 }
550
551 static int thread__symbol_incnew(struct thread *self, struct symbol *sym,
552                                  uint64_t ip, struct dso *dso, char level)
553 {
554         struct rb_node **p = &self->symhists.rb_node;
555         struct rb_node *parent = NULL;
556         struct symhist *sh;
557
558         while (*p != NULL) {
559                 parent = *p;
560                 sh = rb_entry(parent, struct symhist, rb_node);
561
562                 if (sh->sym == sym || ip == sh->ip) {
563                         symhist__inc(sh);
564                         return 0;
565                 }
566
567                 /* Handle unresolved symbols too */
568                 const uint64_t start = !sh->sym ? sh->ip : sh->sym->start;
569
570                 if (ip < start)
571                         p = &(*p)->rb_left;
572                 else
573                         p = &(*p)->rb_right;
574         }
575
576         sh = symhist__new(sym, ip, dso, level);
577         if (sh == NULL)
578                 return -ENOMEM;
579         rb_link_node(&sh->rb_node, parent, p);
580         rb_insert_color(&sh->rb_node, &self->symhists);
581         return 0;
582 }
583
584 static int thread__set_comm(struct thread *self, const char *comm)
585 {
586         self->comm = strdup(comm);
587         return self->comm ? 0 : -ENOMEM;
588 }
589
590 static size_t thread__maps_fprintf(struct thread *self, FILE *fp)
591 {
592         struct map *pos;
593         size_t ret = 0;
594
595         list_for_each_entry(pos, &self->maps, node)
596                 ret += map__fprintf(pos, fp);
597
598         return ret;
599 }
600
601 static size_t thread__fprintf(struct thread *self, FILE *fp)
602 {
603         int ret = fprintf(fp, "thread: %d %s\n", self->pid, self->comm);
604         struct rb_node *nd;
605
606         for (nd = rb_first(&self->symhists); nd; nd = rb_next(nd)) {
607                 struct symhist *pos = rb_entry(nd, struct symhist, rb_node);
608                 ret += symhist__fprintf(pos, fp);
609         }
610
611         return ret;
612 }
613
614 static struct rb_root threads = RB_ROOT;
615
616 static struct thread *threads__findnew(pid_t pid)
617 {
618         struct rb_node **p = &threads.rb_node;
619         struct rb_node *parent = NULL;
620         struct thread *th;
621
622         while (*p != NULL) {
623                 parent = *p;
624                 th = rb_entry(parent, struct thread, rb_node);
625
626                 if (th->pid == pid)
627                         return th;
628
629                 if (pid < th->pid)
630                         p = &(*p)->rb_left;
631                 else
632                         p = &(*p)->rb_right;
633         }
634
635         th = thread__new(pid);
636         if (th != NULL) {
637                 rb_link_node(&th->rb_node, parent, p);
638                 rb_insert_color(&th->rb_node, &threads);
639         }
640         return th;
641 }
642
643 static void thread__insert_map(struct thread *self, struct map *map)
644 {
645         list_add_tail(&map->node, &self->maps);
646 }
647
648 static struct map *thread__find_map(struct thread *self, uint64_t ip)
649 {
650         if (self == NULL)
651                 return NULL;
652
653         struct map *pos;
654
655         list_for_each_entry(pos, &self->maps, node)
656                 if (ip >= pos->start && ip <= pos->end)
657                         return pos;
658
659         return NULL;
660 }
661
662 static void threads__fprintf(FILE *fp)
663 {
664         struct rb_node *nd;
665         for (nd = rb_first(&threads); nd; nd = rb_next(nd)) {
666                 struct thread *pos = rb_entry(nd, struct thread, rb_node);
667                 thread__fprintf(pos, fp);
668         }
669 }
670
671 static void display_help(void)
672 {
673         printf(
674         "Usage: perf-report [<options>]\n"
675         " -i file   --input=<file>      # input file\n"
676         );
677
678         exit(0);
679 }
680
681 static void process_options(int argc, char *argv[])
682 {
683         int error = 0;
684
685         for (;;) {
686                 int option_index = 0;
687                 /** Options for getopt */
688                 static struct option long_options[] = {
689                         {"input",       required_argument,      NULL, 'i'},
690                         {"no-user",     no_argument,            NULL, 'u'},
691                         {"no-kernel",   no_argument,            NULL, 'k'},
692                         {"no-hv",       no_argument,            NULL, 'h'},
693                         {NULL,          0,                      NULL,  0 }
694                 };
695                 int c = getopt_long(argc, argv, "+:i:kuh",
696                                     long_options, &option_index);
697                 if (c == -1)
698                         break;
699
700                 switch (c) {
701                 case 'i': input_name                    = strdup(optarg); break;
702                 case 'k': show_mask &= ~SHOW_KERNEL; break;
703                 case 'u': show_mask &= ~SHOW_USER; break;
704                 case 'h': show_mask &= ~SHOW_HV; break;
705                 default: error = 1; break;
706                 }
707         }
708
709         if (error)
710                 display_help();
711 }
712
713 int cmd_report(int argc, char **argv)
714 {
715         unsigned long offset = 0;
716         unsigned long head = 0;
717         struct stat stat;
718         char *buf;
719         event_t *event;
720         int ret, rc = EXIT_FAILURE;
721         unsigned long total = 0;
722
723         elf_version(EV_CURRENT);
724
725         page_size = getpagesize();
726
727         process_options(argc, argv);
728
729         input = open(input_name, O_RDONLY);
730         if (input < 0) {
731                 perror("failed to open file");
732                 exit(-1);
733         }
734
735         ret = fstat(input, &stat);
736         if (ret < 0) {
737                 perror("failed to stat file");
738                 exit(-1);
739         }
740
741         if (!stat.st_size) {
742                 fprintf(stderr, "zero-sized file, nothing to do!\n");
743                 exit(0);
744         }
745
746         if (load_kallsyms() < 0) {
747                 perror("failed to open kallsyms");
748                 return EXIT_FAILURE;
749         }
750
751 remap:
752         buf = (char *)mmap(NULL, page_size * mmap_window, PROT_READ,
753                            MAP_SHARED, input, offset);
754         if (buf == MAP_FAILED) {
755                 perror("failed to mmap file");
756                 exit(-1);
757         }
758
759 more:
760         event = (event_t *)(buf + head);
761
762         if (head + event->header.size >= page_size * mmap_window) {
763                 unsigned long shift = page_size * (head / page_size);
764                 int ret;
765
766                 ret = munmap(buf, page_size * mmap_window);
767                 assert(ret == 0);
768
769                 offset += shift;
770                 head -= shift;
771                 goto remap;
772         }
773
774
775         if (!event->header.size) {
776                 fprintf(stderr, "zero-sized event at file offset %ld\n", offset + head);
777                 fprintf(stderr, "skipping %ld bytes of events.\n", stat.st_size - offset - head);
778                 goto done;
779         }
780
781         head += event->header.size;
782
783         if (event->header.misc & PERF_EVENT_MISC_OVERFLOW) {
784                 char level;
785                 int show = 0;
786                 struct dso *dso = NULL;
787                 struct thread *thread = threads__findnew(event->ip.pid);
788
789                 if (thread == NULL) {
790                         fprintf(stderr, "problem processing %d event, bailing out\n",
791                                 event->header.type);
792                         goto done;
793                 }
794
795                 if (event->header.misc & PERF_EVENT_MISC_KERNEL) {
796                         show = SHOW_KERNEL;
797                         level = 'k';
798                         dso = kernel_dso;
799                 } else if (event->header.misc & PERF_EVENT_MISC_USER) {
800                         show = SHOW_USER;
801                         level = '.';
802                         struct map *map = thread__find_map(thread, event->ip.ip);
803                         if (map != NULL)
804                                 dso = map->dso;
805                 } else {
806                         show = SHOW_HV;
807                         level = 'H';
808                 }
809
810                 if (show & show_mask) {
811                         struct symbol *sym = dso__find_symbol(dso, event->ip.ip);
812
813                         if (thread__symbol_incnew(thread, sym, event->ip.ip,
814                                                   dso, level)) {
815                                 fprintf(stderr, "problem incrementing symbol count, bailing out\n");
816                                 goto done;
817                         }
818                 }
819                 total++;
820         } else switch (event->header.type) {
821         case PERF_EVENT_MMAP: {
822                 struct thread *thread = threads__findnew(event->mmap.pid);
823                 struct map *map = map__new(&event->mmap);
824
825                 if (thread == NULL || map == NULL) {
826                         fprintf(stderr, "problem processing PERF_EVENT_MMAP, bailing out\n");
827                         goto done;
828                 }
829                 thread__insert_map(thread, map);
830                 break;
831         }
832         case PERF_EVENT_COMM: {
833                 struct thread *thread = threads__findnew(event->comm.pid);
834
835                 if (thread == NULL ||
836                     thread__set_comm(thread, event->comm.comm)) {
837                         fprintf(stderr, "problem processing PERF_EVENT_COMM, bailing out\n");
838                         goto done;
839                 }
840                 break;
841         }
842         }
843
844         if (offset + head < stat.st_size)
845                 goto more;
846
847         rc = EXIT_SUCCESS;
848 done:
849         close(input);
850         //dsos__fprintf(stdout);
851         threads__fprintf(stdout);
852 #if 0
853         std::map<std::string, int>::iterator hi = hist.begin();
854
855         while (hi != hist.end()) {
856                 rev_hist.insert(std::pair<int, std::string>(hi->second, hi->first));
857                 hist.erase(hi++);
858         }
859
860         std::multimap<int, std::string>::const_iterator ri = rev_hist.begin();
861
862         while (ri != rev_hist.end()) {
863                 printf(" %5.2f %s\n", (100.0 * ri->first)/total, ri->second.c_str());
864                 ri++;
865         }
866 #endif
867         return rc;
868 }
869