linux-kernel - RE: [PATCH 1/2] perf,tools: get correct cpu id for print

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Date:	Tue, 30 Jun 2015 13:24:59 +0000
From:	"Liang, Kan" <kan.liang@...el.com>
To:	Jiri Olsa <jolsa@...hat.com>
CC:	"acme@...nel.org" <acme@...nel.org>,
	"jolsa@...nel.org" <jolsa@...nel.org>,
	"ak@...ux.intel.com" <ak@...ux.intel.com>,
	"namhyung@...nel.org" <namhyung@...nel.org>,
	"eranian@...gle.com" <eranian@...gle.com>,
	"Hunter, Adrian" <adrian.hunter@...el.com>,
	"dsahern@...il.com" <dsahern@...il.com>,
	"a.p.zijlstra@...llo.nl" <a.p.zijlstra@...llo.nl>,
	"mingo@...hat.com" <mingo@...hat.com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: RE: [PATCH 1/2] perf,tools: get correct cpu id for print_aggr



> On Mon, Jun 29, 2015 at 03:55:34PM -0400, kan.liang@...el.com wrote:
> > From: Kan Liang <kan.liang@...el.com>
> >
> > print_aggr fails to print per-core/per-socket statistics after commit
> > b7f0c203586b ("perf evlist: Propagate cpu maps to evsels in an
> > evlist"), if events have differnt cpus. Because in print_aggr,
> > aggr_get_id needs index (not cpu id) to find core/pkg id.
> > This patch introduced perf_evsel__get_cpumap_index to get the index
> by
> > cpu id for a given event. The index can be used to find correct cpu id
> > for print_aggr.
> >
> 
> SNIP
> 
> >
> > diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
> > index 37e301a..a3ea735 100644
> > --- a/tools/perf/builtin-stat.c
> > +++ b/tools/perf/builtin-stat.c
> > @@ -708,6 +708,7 @@ static void print_aggr(char *prefix)
> >  			nr = 0;
> >  			for (cpu = 0; cpu < perf_evsel__nr_cpus(counter);
> cpu++) {
> >  				cpu2 = perf_evsel__cpus(counter)-
> >map[cpu];
> > +				cpu2 =
> perf_evsel__get_cpumap_index(cpu2, evsel_list->cpus);
> >  				s2 = aggr_get_id(evsel_list->cpus, cpu2);
> >  				if (s2 != id)
> >  					continue;
> 
> hum, looks like passing the actual cpu number was introduced in:
>   582ec0829b3d perf stat: Fix per-socket output bug for uncore events
> 
Right, I will change it.

> also, we already have the index into counter's cpus, why not use those for
> getting aggregated id (core,socket).. what do I miss?

Yes, the index is already there. But we still pass evlist's cpu map to aggr_get_id.
So once evsel and evlist have different cpu maps (e.g. -a with uncore event),
the wrong aggregated id will be return. 
I think the patch as below will fix all these issues.

Thanks,
Kan

---
diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index 37e301a..47c3c1f 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -694,7 +694,7 @@ static void abs_printout(int id, int nr, struct perf_evsel *evsel, double avg)
 static void print_aggr(char *prefix)
 {
        struct perf_evsel *counter;
-       int cpu, cpu2, s, s2, id, nr;
+       int cpu, s, s2, id, nr;
        double uval;
        u64 ena, run, val;

@@ -707,8 +707,7 @@ static void print_aggr(char *prefix)
                        val = ena = run = 0;
                        nr = 0;
                        for (cpu = 0; cpu < perf_evsel__nr_cpus(counter); cpu++) {
-                               cpu2 = perf_evsel__cpus(counter)->map[cpu];
-                               s2 = aggr_get_id(evsel_list->cpus, cpu2);
+                               s2 = aggr_get_id(perf_evsel__cpus(counter), cpu);
                                if (s2 != id)
                                        continue;
                                val += perf_counts(counter->counts, cpu, 0)->val;
--
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