Messages in this thread Patch in this message |  | | | From | Kirill Smelkov <> | | Subject | [PATCH 5/6] perf top: fix annotate for userspace | | Date | Fri, 8 Jan 2010 15:23:08 +0300 |
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First, for programs and prelinked libraries, annotate code was fooled by objdump output IPs (src->eip in the code) being wrongly converted to absolute IPs. In such case there were no conversion needed, but in
src->eip = strtoull(src->line, NULL, 16); src->eip = map->unmap_ip(map, src->eip); // = eip + map->start - map->pgoff we were reading absolute address from objdump (e.g. 8048604) and then almost doubling it, because eip & map->start are approximately close for small programs.
Needless to say, that later, in record_precise_ip() there was no matching with real runtime IPs.
And second, like with `perf annotate` the problem with non-prelinked *.so was that we were doing rip -> objdump address conversion wrong.
Also, because unlike `perf annotate`, `perf top` code does annotation based on absolute IPs for performance reasons(*), new helper for mapping objdump addresse to IP is introduced.
(*) we get samples info in absolute IPs, and since we do lots of hit-testing on absolute IPs at runtime in record_precise_ip(), it's better to convert objdump addresses to IPs once and do no conversion at runtime.
I also had to fix how objdump output is parsed (with hardcoded 8/16 characters format, which was inappropriate for ET_DYN dsos with small addresses like '4ac')
Also note, that not all objdump output lines has associtated IPs, e.g. look at source lines here:
000004ac <my_strlen>: extern "C" int my_strlen(const char *s) 4ac: 55 push %ebp 4ad: 89 e5 mov %esp,%ebp 4af: 83 ec 10 sub $0x10,%esp { int len = 0; 4b2: c7 45 fc 00 00 00 00 movl $0x0,-0x4(%ebp) 4b9: eb 08 jmp 4c3 <my_strlen+0x17> while (*s) { ++len; 4bb: 83 45 fc 01 addl $0x1,-0x4(%ebp) ++s; 4bf: 83 45 08 01 addl $0x1,0x8(%ebp) So we mark them with eip=0, and ignore such lines in annotate lookup code.
Signed-off-by: Kirill Smelkov <kirr@landau.phys.spbu.ru> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Mike Galbraith <efault@gmx.de> --- tools/perf/builtin-top.c | 24 ++++++++++++++---------- tools/perf/util/map.c | 8 ++++++++ tools/perf/util/map.h | 3 ++- 3 files changed, 24 insertions(+), 11 deletions(-) diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c index 4067e4d..6aa9b02 100644 --- a/tools/perf/builtin-top.c +++ b/tools/perf/builtin-top.c @@ -176,6 +176,7 @@ static void parse_source(struct sym_entry *syme) FILE *file; char command[PATH_MAX*2]; const char *path; + char *tmp; u64 len; if (!syme) @@ -204,8 +205,8 @@ static void parse_source(struct sym_entry *syme) sprintf(command, "objdump --start-address=0x%016Lx " "--stop-address=0x%016Lx -dS %s", - map->unmap_ip(map, sym->start), - map->unmap_ip(map, sym->end), path); + map__rip_2objdump(map, sym->start), + map__rip_2objdump(map, sym->end), path); file = popen(command, "r"); if (!file) @@ -235,14 +236,13 @@ static void parse_source(struct sym_entry *syme) *source->lines_tail = src; source->lines_tail = &src->next; - if (strlen(src->line)>8 && src->line[8] == ':') { - src->eip = strtoull(src->line, NULL, 16); - src->eip = map->unmap_ip(map, src->eip); - } - if (strlen(src->line)>8 && src->line[16] == ':') { - src->eip = strtoull(src->line, NULL, 16); - src->eip = map->unmap_ip(map, src->eip); - } + + src->eip = strtoull(src->line, &tmp, 16); + if (*tmp == ':') + src->eip = map__objdump_2ip(map, src->eip); + else + /* this line has no ip info (e.g. source line) */ + src->eip = 0; } pclose(file); out_assign: @@ -277,6 +277,10 @@ static void record_precise_ip(struct sym_entry *syme, int counter, u64 ip) goto out_unlock; for (line = syme->src->lines; line; line = line->next) { + /* skip lines without IP info */ + if (line->eip == 0) + continue; + if (line->eip == ip) { line->count[counter]++; break; diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c index d6da969..37bfcc5 100644 --- a/tools/perf/util/map.c +++ b/tools/perf/util/map.c @@ -215,3 +215,11 @@ u64 map__rip_2objdump(struct map *map, u64 rip) rip; return addr; } + +u64 map__objdump_2ip(struct map *map, u64 addr) +{ + u64 ip = map->dso->adjust_symbols ? + addr : + map->unmap_ip(map, addr); /* RIP -> IP */ + return ip; +} diff --git a/tools/perf/util/map.h b/tools/perf/util/map.h index 39fa478..2bcd9d4 100644 --- a/tools/perf/util/map.h +++ b/tools/perf/util/map.h @@ -49,8 +49,9 @@ static inline u64 identity__map_ip(struct map *map __used, u64 ip) } -/* rip -> addr suitable for passing to `objdump --start-address=` */ +/* rip/ip <-> addr suitable for passing to `objdump --start-address=` */ u64 map__rip_2objdump(struct map *map, u64 rip); +u64 map__objdump_2ip(struct map *map, u64 addr); struct symbol; -- 1.6.6.79.gd514e.dirty
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