perf annotate: Fix sample events lost in stdio mode

In hist__find_annotations(), since different 'struct hist_entry' entries
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>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Gustavo A. R. Silva <gustavoars@kernel.org>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Martin Liška <mliska@suse.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: zhangjinhao2@huawei.com
Link: http://lore.kernel.org/lkml/20210319123527.173883-1-yangjihong1@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/builtin-annotate.c b/tools/perf/builtin-annotate.c
index 021d974..524e6f0 100644 (file)
--- a/tools/perf/builtin-annotate.c
+++ b/tools/perf/builtin-annotate.c
@@ -374,13 +374,6 @@ find_next:
                } 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);
                }
        }
 }
@@ -623,14 +616,22 @@ int cmd_annotate(int argc, const char **argv)
 
        setup_browser(true);
 
-       if ((use_browser == 1 || annotate.use_stdio2) && annotate.has_br_stack) {
+       /*
+        * 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";
+
+       /*
+        * Set SORT_MODE__BRANCH so that annotate display IPC/Cycle
+        * if branch info is in perf data in TUI mode.
+        */
+       if ((use_browser == 1 || annotate.use_stdio2) && annotate.has_br_stack)
                sort__mode = SORT_MODE__BRANCH;
-               if (setup_sorting(annotate.session->evlist) < 0)
-                       usage_with_options(annotate_usage, options);
-       } else {
-               if (setup_sorting(NULL) < 0)
-                       usage_with_options(annotate_usage, options);
-       }
+
+       if (setup_sorting(NULL) < 0)
+               usage_with_options(annotate_usage, options);
 
        ret = __cmd_annotate(&annotate);