Re: [PATCH 1/3] perf tools: Fix period/freq terms setup

[Jiri Olsa]

On Mon, Feb 05, 2018 at 06:51:05PM -0800, Stephane Eranian wrote:

SNIP

> >
> Looks like this is working then, great!
> 
> Now, related to profiling and reporting. There is still an issue I
> keep running into
> with grouping. I want to sample on N events, where N > number of  hw counters.
> Yet I want the same output as perf report --group, i.e., side-by-side
> profiles as
> opposed to showing me one event profile at a time (which is not very useful).
> 
> You should not require events to belong to the same group to support this. Many
> other tools support such output (e.g., VTUNE, Gooda). It is still very
> valuable even
> though events may not have been measured at the same time.
> 
> Let me use a simple (and silly but portable) example.
> Today if I do on  Intel x86:
> 
>  $ perf record -e branches,branches,branches,branches,branches my_test
> 
> And I do:
> 
> $ perf report --group
> It will show me 5 distinct profiles.
> 
> I would like perf to show me a single profile where the 5 events are
> side-by-side.
> 
> Similar to what I get if I do instead:
> $ perf record -e '{branches,branches,branches,branches}' my_test
> $ perf report --group
> 
> But here, I would have to ensure all events fits in a group to allow
> the reporting
> I want. So that would limit me to 4 events.
> 
> I think perf report --group should work regardless of how the events
> were grouped.
> Is there already a way to work around this?

no workaround.. please try attached patch, it seems
to work for what you described

thanks,
jirka


---
diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index 4ad5dc649716..35a013992092 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -937,6 +937,7 @@ int cmd_report(int argc, const char **argv)
 		"perf report [<options>]",
 		NULL
 	};
+	bool group_set = false;
 	struct report report = {
 		.tool = {
 			.sample		 = process_sample_event,
@@ -1056,7 +1057,7 @@ int cmd_report(int argc, const char **argv)
 		   "Specify disassembler style (e.g. -M intel for intel syntax)"),
 	OPT_BOOLEAN(0, "show-total-period", &symbol_conf.show_total_period,
 		    "Show a column with the sum of periods"),
-	OPT_BOOLEAN(0, "group", &symbol_conf.event_group,
+	OPT_BOOLEAN_SET(0, "group", &symbol_conf.event_group, &group_set,
 		    "Show event group information together"),
 	OPT_CALLBACK_NOOPT('b', "branch-stack", &branch_mode, "",
 		    "use branch records for per branch histogram filling",
@@ -1173,6 +1174,9 @@ int cmd_report(int argc, const char **argv)
 	has_br_stack = perf_header__has_feat(&session->header,
 					     HEADER_BRANCH_STACK);
 
+	if (group_set && !session->evlist->nr_groups)
+		perf_evlist__set_leader(session->evlist);
+
 	if (itrace_synth_opts.last_branch)
 		has_br_stack = true;