Re: [PATCH -tip v2 2/6] perf script: add magic word to indicate the failure of resolving symbols

Akihiro Nagai
2011-07-21T09:36:49Z

(2011/07/18 1:30), David Ahern wrote:
> On 07/17/2011 10:07 AM, David Ahern wrote:
>>
>>
>> On 07/17/2011 03:30 AM, Akihiro Nagai wrote:
>>> Latest perf-script doesn't output symbol name when it failed to
>>> resolve symbol name. This output is not friendly for external scripts
>>> because it causes misaligment. So, this patch adds the magic word
>>> "(unknown)" when perf-script failed to resolve symbols.
>>
>> Code has [unknown] with {}, not ().
>
> Evidently I had the shift key down -- s/{}/[]/. :-) And I see now, for
> dsoname you have [unknown] and for symname (unknown). Use the same for
> both. Since () is already used for separating dsoname, use [unknown] for
> both
At print_sample_start() in builtin-script.c, there is the code that print "(unknown)"
when perf cannnot resolve the event name.

printf("%s: ", evname ? evname : "(unknown)");

On the other hand, at hist_entry__dso_snprintf() in util/sort.c, there is the code
prints "[unknown]" for unresolvable DSO name.

return repsep_snprintf(bf, size, "%-*s", width, "[unknown]");

In addition, perf uses "[]" for DSO name for example "[kernel.kallsyms]".
So, I chose it. However, this specification is not easy for user-scripts.
Should I unify this expression?

Thank you.
>
> David
>
>
>>
>>>
>>> At the same time, this patch changes perf-script to output "[unknown]"
>>> in the DSO field, when it failed to resolve the path of DSOs.
>>>
>>> Changes in v2:
>>> - add this patch
>>>
>>> Signed-off-by: Akihiro Nagai<akihiro.nagai.hw@hitachi.com>
>>> Cc: Peter Zijlstra<peterz@infradead.org>
>>> Cc: Frederic Weisbecker<fweisbec@gmail.com>
>>> Cc: Paul Mackerras<paulus@samba.org>
>>> Cc: Ingo Molnar<mingo@elte.hu>
>>> Cc: Arnaldo Carvalho de Melo<acme@infradead.org>
>>> Cc: David Ahern<dsahern@gmail.com>
>>> Cc: Masami Hiramatsu<masami.hiramatsu.pt@hitachi.com>
>>> ---
>>>
>>> tools/perf/builtin-script.c | 18 +++++-------------
>>> tools/perf/util/map.c | 12 ++++++++++++
>>> tools/perf/util/map.h | 1 +
>>> tools/perf/util/session.c | 35 ++++++++++-------------------------
>>> tools/perf/util/symbol.c | 12 ++++++++++++
>>> tools/perf/util/symbol.h | 1 +
>>> 6 files changed, 41 insertions(+), 38 deletions(-)
>>>
>>> diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
>>> index 09024ec..b3e0951 100644
>>> --- a/tools/perf/builtin-script.c
>>> +++ b/tools/perf/builtin-script.c
>>> @@ -320,7 +320,6 @@ static void print_sample_addr(union perf_event *event,
>>> {
>>> struct addr_location al;
>>> u8 cpumode = event->header.misc& PERF_RECORD_MISC_CPUMODE_MASK;
>>> - const char *symname, *dsoname;
>>>
>>> printf("%16" PRIx64, sample->addr);
>>>
>>> @@ -340,21 +339,14 @@ static void print_sample_addr(union perf_event *event,
>>> al.sym = map__find_symbol(al.map, al.addr, NULL);
>>>
>>> if (PRINT_FIELD(SYM)) {
>>> - if (al.sym&& al.sym->name)
>>> - symname = al.sym->name;
>>> - else
>>> - symname = "";
>>> -
>>> - printf(" %16s", symname);
>>> + printf(" ");
>>> + symbol__print_symname(al.sym);
>>> }
>>>
>>> if (PRINT_FIELD(DSO)) {
>>> - if (al.map&& al.map->dso&& al.map->dso->name)
>>> - dsoname = al.map->dso->name;
>>> - else
>>> - dsoname = "";
>>> -
>>> - printf(" (%s)", dsoname);
>>> + printf(" (");
>>> + map__print_dsoname(al.map);
>>> + printf(")");
>>> }
>>> }
>>>
>>> diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
>>> index a16ecab..dddc0f3 100644
>>> --- a/tools/perf/util/map.c
>>> +++ b/tools/perf/util/map.c
>>> @@ -200,6 +200,18 @@ size_t map__fprintf(struct map *self, FILE *fp)
>>> self->start, self->end, self->pgoff, self->dso->name);
>>> }
>>>
>>> +void map__print_dsoname(struct map *self)
>>> +{
>>> + const char *dsoname;
>>> +
>>> + if (self&& self->dso&& self->dso->name)
>>> + dsoname = self->dso->name;
>>
>> extra tab in the above line.
>>
>> Otherwise looks good to me.
Oops! I fix it. Thank you.
>>
>> Acked-By: dsahern@gmail.com
>>
>>> + else
>>> + dsoname = "[unknown]";
>>> +
>>> + printf("%s", dsoname);
>>> +}
>>> +
>>> /*
>>> * objdump wants/reports absolute IPs for ET_EXEC, and RIPs for ET_DYN.
>>> * map->dso->adjust_symbols==1 for ET_EXEC-like cases.
>>> diff --git a/tools/perf/util/map.h b/tools/perf/util/map.h
>>> index b397c03..6f452b9 100644
>>> --- a/tools/perf/util/map.h
>>> +++ b/tools/perf/util/map.h
>>> @@ -112,6 +112,7 @@ void map__delete(struct map *self);
>>> struct map *map__clone(struct map *self);
>>> int map__overlap(struct map *l, struct map *r);
>>> size_t map__fprintf(struct map *self, FILE *fp);
>>> +void map__print_dsoname(struct map *self);
>>>
>>> int map__load(struct map *self, symbol_filter_t filter);
>>> struct symbol *map__find_symbol(struct map *self,
>>> diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
>>> index 453a010..442be3a 100644
>>> --- a/tools/perf/util/session.c
>>> +++ b/tools/perf/util/session.c
>>> @@ -1214,7 +1214,6 @@ void perf_session__print_ip(union perf_event *event,
>>> int print_sym, int print_dso)
>>> {
>>> struct addr_location al;
>>> - const char *symname, *dsoname;
>>> struct callchain_cursor *cursor =&session->callchain_cursor;
>>> struct callchain_cursor_node *node;
>>>
>>> @@ -1242,20 +1241,13 @@ void perf_session__print_ip(union perf_event *event,
>>>
>>> printf("\t%16" PRIx64, node->ip);
>>> if (print_sym) {
>>> - if (node->sym&& node->sym->name)
>>> - symname = node->sym->name;
>>> - else
>>> - symname = "";
>>> -
>>> - printf(" %s", symname);
>>> + printf(" ");
>>> + symbol__print_symname(node->sym);
>>> }
>>> if (print_dso) {
>>> - if (node->map&& node->map->dso&& node->map->dso->name)
>>> - dsoname = node->map->dso->name;
>>> - else
>>> - dsoname = "";
>>> -
>>> - printf(" (%s)", dsoname);
>>> + printf(" (");
>>> + map__print_dsoname(al.map);
>>> + printf(")");
>>> }
>>> printf("\n");
>>>
>>> @@ -1265,21 +1257,14 @@ void perf_session__print_ip(union perf_event *event,
>>> } else {
>>> printf("%16" PRIx64, sample->ip);
>>> if (print_sym) {
>>> - if (al.sym&& al.sym->name)
>>> - symname = al.sym->name;
>>> - else
>>> - symname = "";
>>> -
>>> - printf(" %s", symname);
>>> + printf(" ");
>>> + symbol__print_symname(al.sym);
>>> }
>>>
>>> if (print_dso) {
>>> - if (al.map&& al.map->dso&& al.map->dso->name)
>>> - dsoname = al.map->dso->name;
>>> - else
>>> - dsoname = "";
>>> -
>>> - printf(" (%s)", dsoname);
>>> + printf(" (");
>>> + map__print_dsoname(al.map);
>>> + printf(")");
>>> }
>>> }
>>> }
>>> diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
>>> index eec1963..85e19c4 100644
>>> --- a/tools/perf/util/symbol.c
>>> +++ b/tools/perf/util/symbol.c
>>> @@ -175,6 +175,18 @@ static size_t symbol__fprintf(struct symbol *sym, FILE *fp)
>>> sym->name);
>>> }
>>>
>>> +void symbol__print_symname(const struct symbol *sym)
>>> +{
>>> + const char *symname;
>>> +
>>> + if (sym&& sym->name)
>>> + symname = sym->name;
>>> + else
>>> + symname = "(unknown)";
>>> +
>>> + printf("%s", symname);
>>> +}
>>> +
>>> void dso__set_long_name(struct dso *dso, char *name)
>>> {
>>> if (name == NULL)
>>> diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h
>>> index 325ee36..1ec17b4 100644
>>> --- a/tools/perf/util/symbol.h
>>> +++ b/tools/perf/util/symbol.h
>>> @@ -238,6 +238,7 @@ void machines__destroy_guest_kernel_maps(struct rb_root *machines);
>>>
>>> int symbol__init(void);
>>> void symbol__exit(void);
>>> +void symbol__print_symname(const struct symbol *sym);
>>> bool symbol_type__is_a(char symbol_type, enum map_type map_type);
>>>
>>> size_t machine__fprintf_vmlinux_path(struct machine *machine, FILE *fp);
>>>