Re: [RFC PATCH 1/1] perf arm64: Implement --topdown with metrics

[Andrew Kilroy]

On 17/12/2021 10:19, John Garry wrote:
> And there is no colouring for results which are above/below standard 
> thresholds (see stat-shadow.c:get_radio_color()).
>
> My impression is that we're not plugging the results from 
> metricgroup__parse_groups_to_evlist() into the --topdown print 
> functionality properly.

The --topdown kernel event colouring is dictated by a large if-else 
statement in stat-shadow.c:perf_stat__print_shadow_stats.

There are branches depending on what is returned by 
perf_stat_evsel__is() for example

	} else if (perf_stat_evsel__is(evsel, TOPDOWN_FETCH_BUBBLES)) {
		double fe_bound = td_fe_bound(cpu, st, &rsd);

		if (fe_bound > 0.2)
			color = PERF_COLOR_RED;
		print_metric(config, ctxp, color, "%8.1f%%", "frontend bound",
				fe_bound * 100.);
	} else if (perf_stat_evsel__is(evsel, TOPDOWN_SLOTS_RETIRED)) {



Because the patches are enabling metrics (equivalent of the -M 
'somemetricname' option), the perf_stat__print_shadow_stats function 
always makes calls to generic_metric(), where colours are never picked.

Seeing thresholds like:

  retiring > 0.7
  fe_bound > 0.2
  be_bound > 0.2
  bad_spec > 0.1


I'm not sure about adding the colouring really.  Are these thresholds 
x86 specific?


> Thanks,
> John


Andrew