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