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

[Yang Jihong]

In hist__find_annotations function, since have a hist_entry per IP for the 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 add a u8 member to struct sym_hist and use a bit to
indicate whether the symbol has been processed.
Because different types of event correspond to different sym_hist, no conflict
occurs.
---
 tools/perf/builtin-annotate.c | 22 ++++++++++++++--------
 tools/perf/util/annotate.h    |  4 ++++
 2 files changed, 18 insertions(+), 8 deletions(-)

diff --git a/tools/perf/builtin-annotate.c b/tools/perf/builtin-annotate.c
index a23ba6bb99b6..c8c67892ae82 100644
--- a/tools/perf/builtin-annotate.c
+++ b/tools/perf/builtin-annotate.c
@@ -372,15 +372,21 @@ static void hists__find_annotations(struct hists *hists,
                        if (next != NULL)
                                nd = next;
                } else {
-                       hist_entry__tty_annotate(he, evsel, ann);
+                       struct sym_hist *h = 
annotated_source__histogram(notes->src,
+                                                                        
evsel->idx);
+
+                       if (h->processed == 0) {
+                               hist_entry__tty_annotate(he, evsel, ann);
+
+                               /*
+                                * Since we have a hist_entry per IP for the 
same
+                                * symbol, set processed flag of evsel in 
sym_hist
+                                * to signal we already processed this symbol.
+                                */
+                               h->processed = 1;
+                       }
+
                        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);
                }
        }
 }
diff --git a/tools/perf/util/annotate.h b/tools/perf/util/annotate.h
index 096cdaf21b01..89872bfdc958 100644
--- a/tools/perf/util/annotate.h
+++ b/tools/perf/util/annotate.h
@@ -228,6 +228,10 @@ void symbol__calc_percent(struct symbol *sym, struct evsel 
*evsel);
 struct sym_hist {
        u64                   nr_samples;
        u64                   period;
+
+       u8                    processed  : 1, /* whether symbol has been 
processed, used for annotate */
+                             __reserved : 7;
+
        struct sym_hist_entry addr[];
 };
 
-- 
2.30.GIT