[PATCH v6] perf annotate: Fix sample events lost in stdio mode

[PATCH v6] perf annotate: Fix sample events lost in stdio mode

[Yang Jihong]

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.

Signed-off-by: Yang Jihong <yangjihong1@huawei.com>
---

Changes since v5:
  - Add Signed-off-by tag.

Changes since v4:
  - Use the same sort key "dso,symbol" in branch stack mode.

Changes since v3:
  - Modify the first line of comments.

Changes since v2:
  - Remove zfree in hists__find_annotations.
  - Change sort order to avoid duplicate output.

Changes since v1:
  - Change processed flag variable from u8 to bool.

 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..92c55f292c11 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);
 		}
 	}
 }
@@ -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)
-- 
2.30.GIT

Re: [PATCH v6] perf annotate: Fix sample events lost in stdio mode

[Namhyung Kim]

Hello,

On Wed, Mar 17, 2021 at 6:44 PM Yang Jihong <yangjihong1@huawei.com> 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.
>
> Signed-off-by: Yang Jihong <yangjihong1@huawei.com>
> ---
>
> Changes since v5:
>   - Add Signed-off-by tag.
>
> Changes since v4:
>   - Use the same sort key "dso,symbol" in branch stack mode.
>
> Changes since v3:
>   - Modify the first line of comments.
>
> Changes since v2:
>   - Remove zfree in hists__find_annotations.
>   - Change sort order to avoid duplicate output.
>
> Changes since v1:
>   - Change processed flag variable from u8 to bool.
>
>  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..92c55f292c11 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);
>                 }
>         }
>  }
> @@ -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";

At this point, I think there's not much value having separate
setup_sorting() for branch mode.

Thanks,
Namhyung


>         if ((use_browser == 1 || annotate.use_stdio2) && annotate.has_br_stack) {
>                 sort__mode = SORT_MODE__BRANCH;
>                 if (setup_sorting(annotate.session->evlist) < 0)
> --
> 2.30.GIT
>

Re: [PATCH v6] perf annotate: Fix sample events lost in stdio mode

[Yang Jihong]

On 2021/3/18 14:13, Namhyung Kim wrote:
> Hello,
> 
> On Wed, Mar 17, 2021 at 6:44 PM Yang Jihong <yangjihong1@huawei.com> 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.
>>
>> Signed-off-by: Yang Jihong <yangjihong1@huawei.com>
>> ---
>>
>> Changes since v5:
>>    - Add Signed-off-by tag.
>>
>> Changes since v4:
>>    - Use the same sort key "dso,symbol" in branch stack mode.
>>
>> Changes since v3:
>>    - Modify the first line of comments.
>>
>> Changes since v2:
>>    - Remove zfree in hists__find_annotations.
>>    - Change sort order to avoid duplicate output.
>>
>> Changes since v1:
>>    - Change processed flag variable from u8 to bool.
>>
>>   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..92c55f292c11 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);
>>                  }
>>          }
>>   }
>> @@ -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";
> 
> At this point, I think there's not much value having separate
> setup_sorting() for branch mode.
> 
Yes, two setup_sorting can be combined into one setup_sorting(NULL),
the v7 patch has been submitted, please check it :)

https://lore.kernel.org/patchwork/patch/1399031/

Thanks,
Yang
> Thanks,
> Namhyung
> 
> 
>>          if ((use_browser == 1 || annotate.use_stdio2) && annotate.has_br_stack) {
>>                  sort__mode = SORT_MODE__BRANCH;
>>                  if (setup_sorting(annotate.session->evlist) < 0)
>> --
>> 2.30.GIT
>>
> .
> 

Re: [PATCH v6] perf annotate: Fix sample events lost in stdio mode

[Yang Jihong]

Hello，

On 2021/3/18 14:13, Namhyung Kim wrote:
> Hello,
> 
> On Wed, Mar 17, 2021 at 6:44 PM Yang Jihong <yangjihong1@huawei.com> 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.
>>
>> Signed-off-by: Yang Jihong <yangjihong1@huawei.com>
>> ---
>>
>> Changes since v5:
>>    - Add Signed-off-by tag.
>>
>> Changes since v4:
>>    - Use the same sort key "dso,symbol" in branch stack mode.
>>
>> Changes since v3:
>>    - Modify the first line of comments.
>>
>> Changes since v2:
>>    - Remove zfree in hists__find_annotations.
>>    - Change sort order to avoid duplicate output.
>>
>> Changes since v1:
>>    - Change processed flag variable from u8 to bool.
>>
>>   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..92c55f292c11 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);
>>                  }
>>          }
>>   }
>> @@ -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";
> 
> At this point, I think there's not much value having separate
> setup_sorting() for branch mode.
> 

I've resubmitted the patch for v7 as suggested below:
https://lore.kernel.org/patchwork/patch/1399031/

Is there anything else that needs to be modified?
Please take some time to review, thank you for your patience :)


Thanks,
Yang
> Thanks,
> Namhyung
> 
> 
>>          if ((use_browser == 1 || annotate.use_stdio2) && annotate.has_br_stack) {
>>                  sort__mode = SORT_MODE__BRANCH;
>>                  if (setup_sorting(annotate.session->evlist) < 0)
>> --
>> 2.30.GIT
>>
> .
>