2021-03-13 02:17:51

by Yang Jihong

[permalink] [raw]
Subject: [PATCH v4] perf annotate: Fix sample events lost in stdio mode

In hist__find_annotations function, since different hist_entry may point to same
symbol, we free notes->src to signal already processed this symbol in stdio mode;
when annotate, entry will skipped if notes->src is NULL to avoid repeated output.

However, there is a problem, for example, run the following command:

# perf record -e branch-misses -e branch-instructions -a sleep 1

perf.data file contains different types of sample event.

If the same IP sample event exists in branch-misses and branch-instructions,
this event uses the same symbol. When annotate branch-misses events, notes->src
corresponding to this event is set to null, as a result, when annotate
branch-instructions events, this event is skipped and no annotate is output.

Solution of this patch is to remove zfree in hists__find_annotations and
change sort order to "dso,symbol" to avoid duplicate output when different
processes correspond to the same symbol.
---
tools/perf/builtin-annotate.c | 13 ++++++-------
1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/tools/perf/builtin-annotate.c b/tools/perf/builtin-annotate.c
index a23ba6bb99b6..ad169e3e2e8f 100644
--- a/tools/perf/builtin-annotate.c
+++ b/tools/perf/builtin-annotate.c
@@ -374,13 +374,6 @@ static void hists__find_annotations(struct hists *hists,
} else {
hist_entry__tty_annotate(he, evsel, ann);
nd = rb_next(nd);
- /*
- * Since we have a hist_entry per IP for the same
- * symbol, free he->ms.sym->src to signal we already
- * processed this symbol.
- */
- zfree(&notes->src->cycles_hist);
- zfree(&notes->src);
}
}
}
@@ -624,6 +617,12 @@ int cmd_annotate(int argc, const char **argv)
if (setup_sorting(annotate.session->evlist) < 0)
usage_with_options(annotate_usage, options);
} else {
+ /*
+ * Events of different processes may correspond to the same
+ * symbol, we do not care about the processes in annotate,
+ * set sort order to avoid repeated output.
+ */
+ sort_order = "dso,symbol";
if (setup_sorting(NULL) < 0)
usage_with_options(annotate_usage, options);
}
--
2.30.GIT


2021-03-13 03:08:39

by Namhyung Kim

[permalink] [raw]
Subject: Re: [PATCH v4] perf annotate: Fix sample events lost in stdio mode

On Sat, Mar 13, 2021 at 11:16 AM Yang Jihong <[email protected]> wrote:
>
> In hist__find_annotations function, since different hist_entry may point to same
> symbol, we free notes->src to signal already processed this symbol in stdio mode;
> when annotate, entry will skipped if notes->src is NULL to avoid repeated output.
>
> However, there is a problem, for example, run the following command:
>
> # perf record -e branch-misses -e branch-instructions -a sleep 1
>
> perf.data file contains different types of sample event.
>
> If the same IP sample event exists in branch-misses and branch-instructions,
> this event uses the same symbol. When annotate branch-misses events, notes->src
> corresponding to this event is set to null, as a result, when annotate
> branch-instructions events, this event is skipped and no annotate is output.
>
> Solution of this patch is to remove zfree in hists__find_annotations and
> change sort order to "dso,symbol" to avoid duplicate output when different
> processes correspond to the same symbol.

Looks good. But I'm not sure about the branch stack mode.
I suspect we can use the same sort key there.

Jin Yao, what do you think?

Thanks,
Namhyung

> ---
> tools/perf/builtin-annotate.c | 13 ++++++-------
> 1 file changed, 6 insertions(+), 7 deletions(-)
>
> diff --git a/tools/perf/builtin-annotate.c b/tools/perf/builtin-annotate.c
> index a23ba6bb99b6..ad169e3e2e8f 100644
> --- a/tools/perf/builtin-annotate.c
> +++ b/tools/perf/builtin-annotate.c
> @@ -374,13 +374,6 @@ static void hists__find_annotations(struct hists *hists,
> } else {
> hist_entry__tty_annotate(he, evsel, ann);
> nd = rb_next(nd);
> - /*
> - * Since we have a hist_entry per IP for the same
> - * symbol, free he->ms.sym->src to signal we already
> - * processed this symbol.
> - */
> - zfree(&notes->src->cycles_hist);
> - zfree(&notes->src);
> }
> }
> }
> @@ -624,6 +617,12 @@ int cmd_annotate(int argc, const char **argv)
> if (setup_sorting(annotate.session->evlist) < 0)
> usage_with_options(annotate_usage, options);
> } else {
> + /*
> + * Events of different processes may correspond to the same
> + * symbol, we do not care about the processes in annotate,
> + * set sort order to avoid repeated output.
> + */
> + sort_order = "dso,symbol";
> if (setup_sorting(NULL) < 0)
> usage_with_options(annotate_usage, options);
> }
> --
> 2.30.GIT
>

2021-03-15 08:50:59

by Yang Jihong

[permalink] [raw]
Subject: Re: [PATCH v4] perf annotate: Fix sample events lost in stdio mode

Hi,

On 2021/3/13 11:06, Namhyung Kim wrote:
> On Sat, Mar 13, 2021 at 11:16 AM Yang Jihong <[email protected]> wrote:
>>
>> In hist__find_annotations function, since different hist_entry may point to same
>> symbol, we free notes->src to signal already processed this symbol in stdio mode;
>> when annotate, entry will skipped if notes->src is NULL to avoid repeated output.
>>
>> However, there is a problem, for example, run the following command:
>>
>> # perf record -e branch-misses -e branch-instructions -a sleep 1
>>
>> perf.data file contains different types of sample event.
>>
>> If the same IP sample event exists in branch-misses and branch-instructions,
>> this event uses the same symbol. When annotate branch-misses events, notes->src
>> corresponding to this event is set to null, as a result, when annotate
>> branch-instructions events, this event is skipped and no annotate is output.
>>
>> Solution of this patch is to remove zfree in hists__find_annotations and
>> change sort order to "dso,symbol" to avoid duplicate output when different
>> processes correspond to the same symbol.
>
> Looks good. But I'm not sure about the branch stack mode.
> I suspect we can use the same sort key there.
>
> Jin Yao, what do you think?
>
> Thanks,
> Namhyung
>
Is it changed to the following?
--- a/tools/perf/builtin-annotate.c
+++ b/tools/perf/builtin-annotate.c
@@ -374,13 +374,6 @@ static void hists__find_annotations(struct hists
*hists,
} else {
hist_entry__tty_annotate(he, evsel, ann);
nd = rb_next(nd);
- /*
- * Since we have a hist_entry per IP for the same
- * symbol, free he->ms.sym->src to signal we already
- * processed this symbol.
- */
- zfree(&notes->src->cycles_hist);
- zfree(&notes->src);
}
}
}
@@ -619,6 +612,12 @@ int cmd_annotate(int argc, const char **argv)

setup_browser(true);

+ /*
+ * Events of different processes may correspond to the same
+ * symbol, we do not care about the processes in annotate,
+ * set sort order to avoid repeated output.
+ */
+ sort_order = "dso,symbol";
if ((use_browser == 1 || annotate.use_stdio2) &&
annotate.has_br_stack) {
sort__mode = SORT_MODE__BRANCH;
if (setup_sorting(annotate.session->evlist) < 0)

I think branch stack mode also don't care about the processes.

>> ---
>> tools/perf/builtin-annotate.c | 13 ++++++-------
>> 1 file changed, 6 insertions(+), 7 deletions(-)
>>
>> diff --git a/tools/perf/builtin-annotate.c b/tools/perf/builtin-annotate.c
>> index a23ba6bb99b6..ad169e3e2e8f 100644
>> --- a/tools/perf/builtin-annotate.c
>> +++ b/tools/perf/builtin-annotate.c
>> @@ -374,13 +374,6 @@ static void hists__find_annotations(struct hists *hists,
>> } else {
>> hist_entry__tty_annotate(he, evsel, ann);
>> nd = rb_next(nd);
>> - /*
>> - * Since we have a hist_entry per IP for the same
>> - * symbol, free he->ms.sym->src to signal we already
>> - * processed this symbol.
>> - */
>> - zfree(&notes->src->cycles_hist);
>> - zfree(&notes->src);
>> }
>> }
>> }
>> @@ -624,6 +617,12 @@ int cmd_annotate(int argc, const char **argv)
>> if (setup_sorting(annotate.session->evlist) < 0)
>> usage_with_options(annotate_usage, options);
>> } else {
>> + /*
>> + * Events of different processes may correspond to the same
>> + * symbol, we do not care about the processes in annotate,
>> + * set sort order to avoid repeated output.
>> + */
>> + sort_order = "dso,symbol";
>> if (setup_sorting(NULL) < 0)
>> usage_with_options(annotate_usage, options);
>> }
>> --
>> 2.30.GIT
>>
> .
>

2021-03-16 11:24:21

by Yang Jihong

[permalink] [raw]
Subject: Re: [PATCH v4] perf annotate: Fix sample events lost in stdio mode

Hello,

On 2021/3/13 11:06, Namhyung Kim wrote:
> On Sat, Mar 13, 2021 at 11:16 AM Yang Jihong <[email protected]> wrote:
>>
>> In hist__find_annotations function, since different hist_entry may point to same
>> symbol, we free notes->src to signal already processed this symbol in stdio mode;
>> when annotate, entry will skipped if notes->src is NULL to avoid repeated output.
>>
>> However, there is a problem, for example, run the following command:
>>
>> # perf record -e branch-misses -e branch-instructions -a sleep 1
>>
>> perf.data file contains different types of sample event.
>>
>> If the same IP sample event exists in branch-misses and branch-instructions,
>> this event uses the same symbol. When annotate branch-misses events, notes->src
>> corresponding to this event is set to null, as a result, when annotate
>> branch-instructions events, this event is skipped and no annotate is output.
>>
>> Solution of this patch is to remove zfree in hists__find_annotations and
>> change sort order to "dso,symbol" to avoid duplicate output when different
>> processes correspond to the same symbol.
>
> Looks good. But I'm not sure about the branch stack mode.
> I suspect we can use the same sort key there.
>
I've submitted the v5 patch which uses same sort key in branch stack
mode, look forward to your review:
https://lore.kernel.org/patchwork/patch/1396841/

Thanks,
Yang.

> Jin Yao, what do you think?
>
> Thanks,
> Namhyung
>
>> ---
>> tools/perf/builtin-annotate.c | 13 ++++++-------
>> 1 file changed, 6 insertions(+), 7 deletions(-)
>>
>> diff --git a/tools/perf/builtin-annotate.c b/tools/perf/builtin-annotate.c
>> index a23ba6bb99b6..ad169e3e2e8f 100644
>> --- a/tools/perf/builtin-annotate.c
>> +++ b/tools/perf/builtin-annotate.c
>> @@ -374,13 +374,6 @@ static void hists__find_annotations(struct hists *hists,
>> } else {
>> hist_entry__tty_annotate(he, evsel, ann);
>> nd = rb_next(nd);
>> - /*
>> - * Since we have a hist_entry per IP for the same
>> - * symbol, free he->ms.sym->src to signal we already
>> - * processed this symbol.
>> - */
>> - zfree(&notes->src->cycles_hist);
>> - zfree(&notes->src);
>> }
>> }
>> }
>> @@ -624,6 +617,12 @@ int cmd_annotate(int argc, const char **argv)
>> if (setup_sorting(annotate.session->evlist) < 0)
>> usage_with_options(annotate_usage, options);
>> } else {
>> + /*
>> + * Events of different processes may correspond to the same
>> + * symbol, we do not care about the processes in annotate,
>> + * set sort order to avoid repeated output.
>> + */
>> + sort_order = "dso,symbol";
>> if (setup_sorting(NULL) < 0)
>> usage_with_options(annotate_usage, options);
>> }
>> --
>> 2.30.GIT
>>
> .
>