perf hists: Check if a hist_entry has callchains before using them

So far if we use 'perf record -g' this will make
symbol_conf.use_callchain 'true' and logic will assume that all events
have callchains enabled, but ever since we added the possibility of
setting up callchains for some events (e.g.: -e
cycles/call-graph=dwarf/) while not for others, we limit usage scenarios
by looking at that symbol_conf.use_callchain global boolean, we better
look at each event attributes.

On the road to that we need to look if a hist_entry has callchains, that
is, to go from hist_entry->hists to the evsel that contains it, to then
look at evsel->sample_type for PERF_SAMPLE_CALLCHAIN.

The next step is to add a symbol_conf.ignore_callchains global, to use
in the places where what we really want to know is if callchains should
be ignored, even if present.

Then -g will mean just to select a callchain mode to be applied to all
events not explicitely setting some other callchain mode, i.e. a default
callchain mode, and --no-call-graph will set
symbol_conf.ignore_callchains with that clear intention.

That too will at some point become a per evsel thing, that tools can set
for all or just a few of its evsels.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-0sas5cm4dsw2obn75g7ruz69@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

3 files changed, 13 insertions, 7 deletions

diff --git a/tools/perf/util/hist.c b/tools/perf/util/hist.c
index 34864c87cd3c..52e8fda93a47 100644
--- a/tools/perf/util/hist.c
+++ b/tools/perf/util/hist.c
@@ -410,7 +410,7 @@ static int hist_entry__init(struct hist_entry *he,
 		map__get(he->mem_info->daddr.map);
 	}
 
-	if (symbol_conf.use_callchain)
+	if (hist_entry__has_callchains(he) && symbol_conf.use_callchain)
 		callchain_init(he->callchain);
 
 	if (he->raw_data) {
@@ -492,7 +492,7 @@ static u8 symbol__parent_filter(const struct symbol *parent)
 
 static void hist_entry__add_callchain_period(struct hist_entry *he, u64 period)
 {
-	if (!symbol_conf.use_callchain)
+	if (!hist_entry__has_callchains(he) || !symbol_conf.use_callchain)
 		return;
 
 	he->hists->callchain_period += period;
@@ -986,7 +986,7 @@ iter_add_next_cumulative_entry(struct hist_entry_iter *iter,
 	iter->he = he;
 	he_cache[iter->curr++] = he;
 
-	if (symbol_conf.use_callchain)
+	if (hist_entry__has_callchains(he) && symbol_conf.use_callchain)
 		callchain_append(he->callchain, &cursor, sample->period);
 	return 0;
 }
@@ -1373,7 +1373,8 @@ static int hists__hierarchy_insert_entry(struct hists *hists,
 	if (new_he) {
 		new_he->leaf = true;
 
-		if (symbol_conf.use_callchain) {
+		if (hist_entry__has_callchains(new_he) &&
+		    symbol_conf.use_callchain) {
 			callchain_cursor_reset(&callchain_cursor);
 			if (callchain_merge(&callchain_cursor,
 					    new_he->callchain,
@@ -1414,7 +1415,7 @@ static int hists__collapse_insert_entry(struct hists *hists,
 			if (symbol_conf.cumulate_callchain)
 				he_stat__add_stat(iter->stat_acc, he->stat_acc);
 
-			if (symbol_conf.use_callchain) {
+			if (hist_entry__has_callchains(he) && symbol_conf.use_callchain) {
 				callchain_cursor_reset(&callchain_cursor);
 				if (callchain_merge(&callchain_cursor,
 						    iter->callchain,
diff --git a/tools/perf/util/hist.h b/tools/perf/util/hist.h
index cafafbf2aa9f..06607c434949 100644
--- a/tools/perf/util/hist.h
+++ b/tools/perf/util/hist.h
@@ -220,6 +220,12 @@ static inline struct hists *evsel__hists(struct perf_evsel *evsel)
 	return &hevsel->hists;
 }
 
+static __pure inline bool hists__has_callchains(struct hists *hists)
+{
+	const struct perf_evsel *evsel = hists_to_evsel(hists);
+	return evsel__has_callchain(evsel);
+}
+
 int hists__init(void);
 int __hists__init(struct hists *hists, struct perf_hpp_list *hpp_list);
 
diff --git a/tools/perf/util/sort.h b/tools/perf/util/sort.h
index 1a046157bfef..7cf2d5cc038e 100644
--- a/tools/perf/util/sort.h
+++ b/tools/perf/util/sort.h
@@ -153,8 +153,7 @@ struct hist_entry {
 
 static __pure inline bool hist_entry__has_callchains(struct hist_entry *he)
 {
-	const struct perf_evsel *evsel = hists_to_evsel(he->hists);
-	return evsel__has_callchain(evsel);
+	return hists__has_callchains(he->hists);
 }
 
 static inline bool hist_entry__has_pairs(struct hist_entry *he)