Re: [PATCH v4] perf annotate: Fix missing number of samples for source_line_samples

From: Taeung Song
Date: Tue Mar 28 2017 - 10:22:10 EST




On 03/28/2017 10:48 PM, Arnaldo Carvalho de Melo wrote:
Em Tue, Mar 28, 2017 at 09:12:05PM +0900, Taeung Song escreveu:
The option 'show-total-period' works fine without a option '-l'.
But if running 'perf annotate --stdio -l --show-total-period',
you can see a problem showing only zero '0' for number of samples.

If you do that at that point, don't you have to change the TUI not to do
it again?

- Arnaldo


Yes, there isn't the same problem when using 't' on TUI of 'perf annotate'.
(As you know, 't' is show-total-period option)

In 'annotate' TUI, we can use the 't' functionality without the problem.
Because of the code (util/annotate.c:911 and ui/browsers/annotate.c:412) as below.

881 double disasm__calc_percent(struct annotation *notes, int evidx, s64 offset,
882 s64 end, const char **path, u64 *nr_samples)
883 {
...
910 if (h->sum) {
911 *nr_samples = hits;

And,

378 static void annotate_browser__calc_percent(struct annotate_browser *browser,
379 struct perf_evsel *evsel)
380 {
...
407 bpos->samples[i].percent = disasm__calc_percent(notes,
408 evsel->idx + i,
409 pos->offset,
410 next ? next->offset : len,
411 &path, &nr_samples);
412 bpos->samples[i].nr = nr_samples;


And 'perf annotate --stdio --show-total-period' hasn't the problem, too.
Because of the same code (util/annotate.c:911).


But if with '-l', i.e. 'perf annotate --stdio -l --show-total-period',
the problem happen. Because 'nr' of source_line_samples aren't ordinarily set
in symbol__get_source_line() (util/annotate.c:1634~..)
,so fix it as this patch

Are there something I missed or misunderstand ?


Thanks,
Taeung


Before:
$ perf annotate --stdio -l --show-total-period
...
0 : 400816: push %rbp
0 : 400817: mov %rsp,%rbp
0 : 40081a: mov %edi,-0x24(%rbp)
0 : 40081d: mov %rsi,-0x30(%rbp)
0 : 400821: mov -0x24(%rbp),%eax
0 : 400824: mov -0x30(%rbp),%rdx
0 : 400828: mov (%rdx),%esi
0 : 40082a: mov $0x0,%edx
...

The reason is it was missed to set number of samples
of source_line_samples, so set it ordinarily.

After:
$ perf annotate --stdio -l --show-total-period
...
3 : 400816: push %rbp
4 : 400817: mov %rsp,%rbp
0 : 40081a: mov %edi,-0x24(%rbp)
0 : 40081d: mov %rsi,-0x30(%rbp)
1 : 400821: mov -0x24(%rbp),%eax
2 : 400824: mov -0x30(%rbp),%rdx
0 : 400828: mov (%rdx),%esi
1 : 40082a: mov $0x0,%edx
...

Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Martin Liska <mliska@xxxxxxx>
Fixes: 0c4a5bcea460 ("perf annotate: Display total number of samples with --show-total-period")
Signed-off-by: Taeung Song <treeze.taeung@xxxxxxxxx>
---
tools/perf/util/annotate.c | 6 ++++--
tools/perf/util/annotate.h | 2 +-
2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
index 11af5f0..a37032b 100644
--- a/tools/perf/util/annotate.c
+++ b/tools/perf/util/annotate.c
@@ -1665,7 +1665,7 @@ static int symbol__get_source_line(struct symbol *sym, struct map *map,
start = map__rip_2objdump(map, sym->start);

for (i = 0; i < len; i++) {
- u64 offset;
+ u64 offset, nr_samples;
double percent_max = 0.0;

src_line->nr_pcnt = nr_pcnt;
@@ -1674,12 +1674,14 @@ static int symbol__get_source_line(struct symbol *sym, struct map *map,
double percent = 0.0;

h = annotation__histogram(notes, evidx + k);
+ nr_samples = h->addr[i];
if (h->sum)
- percent = 100.0 * h->addr[i] / h->sum;
+ percent = 100.0 * nr_samples / h->sum;

if (percent > percent_max)
percent_max = percent;
src_line->samples[k].percent = percent;
+ src_line->samples[k].nr = nr_samples;
}

if (percent_max <= 0.5)
diff --git a/tools/perf/util/annotate.h b/tools/perf/util/annotate.h
index 09776b5..948aa8e 100644
--- a/tools/perf/util/annotate.h
+++ b/tools/perf/util/annotate.h
@@ -98,7 +98,7 @@ struct cyc_hist {
struct source_line_samples {
double percent;
double percent_sum;
- double nr;
+ u64 nr;
};

struct source_line {
--
2.7.4