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>

1 files changed, 6 insertions, 5 deletions

diff --git a/tools/perf/ui/browsers/hists.c b/tools/perf/ui/browsers/hists.c
index 22054107f1af..a96f62ca984a 100644
--- a/tools/perf/ui/browsers/hists.c
+++ b/tools/perf/ui/browsers/hists.c
@@ -1231,6 +1231,7 @@ static int hist_browser__show_entry(struct hist_browser *browser,
 	int width = browser->b.width;
 	char folded_sign = ' ';
 	bool current_entry = ui_browser__is_current_entry(&browser->b, row);
+	bool use_callchain = hist_entry__has_callchains(entry) && symbol_conf.use_callchain;
 	off_t row_offset = entry->row_offset;
 	bool first = true;
 	struct perf_hpp_fmt *fmt;
@@ -1240,7 +1241,7 @@ static int hist_browser__show_entry(struct hist_browser *browser,
 		browser->selection = &entry->ms;
 	}
 
-	if (symbol_conf.use_callchain) {
+	if (use_callchain) {
 		hist_entry__init_have_children(entry);
 		folded_sign = hist_entry__folded(entry);
 	}
@@ -1276,7 +1277,7 @@ static int hist_browser__show_entry(struct hist_browser *browser,
 			}
 
 			if (first) {
-				if (symbol_conf.use_callchain) {
+				if (use_callchain) {
 					ui_browser__printf(&browser->b, "%c ", folded_sign);
 					width -= 2;
 				}
@@ -1583,7 +1584,7 @@ hists_browser__scnprintf_headers(struct hist_browser *browser, char *buf,
 	int column = 0;
 	int span = 0;
 
-	if (symbol_conf.use_callchain) {
+	if (hists__has_callchains(hists) && symbol_conf.use_callchain) {
 		ret = scnprintf(buf, size, "  ");
 		if (advance_hpp_check(&dummy_hpp, ret))
 			return ret;
@@ -1987,7 +1988,7 @@ static int hist_browser__fprintf_entry(struct hist_browser *browser,
 	bool first = true;
 	int ret;
 
-	if (symbol_conf.use_callchain) {
+	if (hist_entry__has_callchains(he) && symbol_conf.use_callchain) {
 		folded_sign = hist_entry__folded(he);
 		printed += fprintf(fp, "%c ", folded_sign);
 	}
@@ -2671,7 +2672,7 @@ static void hist_browser__update_percent_limit(struct hist_browser *hb,
 			he->nr_rows = 0;
 		}
 
-		if (!he->leaf || !symbol_conf.use_callchain)
+		if (!he->leaf || !hist_entry__has_callchains(he) || !symbol_conf.use_callchain)
 			goto next;
 
 		if (callchain_param.mode == CHAIN_GRAPH_REL) {