linux-kernel - Re: [PATCH] perf stat: fix per-pkg event reporting bug

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Date:	Thu, 3 Sep 2015 05:16:41 -0700
From:	Stephane Eranian <eranian@...gle.com>
To:	Jiri Olsa <jolsa@...hat.com>
Cc:	LKML <linux-kernel@...r.kernel.org>,
	Arnaldo Carvalho de Melo <acme@...hat.com>,
	Peter Zijlstra <peterz@...radead.org>,
	"mingo@...e.hu" <mingo@...e.hu>,
	"ak@...ux.intel.com" <ak@...ux.intel.com>,
	Namhyung Kim <namhyung@...nel.org>,
	"Liang, Kan" <kan.liang@...el.com>,
	David Ahern <dsahern@...il.com>,
	Adrian Hunter <adrian.hunter@...el.com>
Subject: Re: [PATCH] perf stat: fix per-pkg event reporting bug

On Thu, Sep 3, 2015 at 5:13 AM, Jiri Olsa <jolsa@...hat.com> wrote:
> On Thu, Sep 03, 2015 at 05:05:32AM -0700, Stephane Eranian wrote:
>> On Thu, Sep 3, 2015 at 5:01 AM, Jiri Olsa <jolsa@...hat.com> wrote:
>> > On Thu, Sep 03, 2015 at 04:48:52AM -0700, Stephane Eranian wrote:
>> >> On Thu, Sep 3, 2015 at 3:01 AM, Jiri Olsa <jolsa@...hat.com> wrote:
>> >> > On Wed, Sep 02, 2015 at 03:17:51PM +0200, Stephane Eranian wrote:
>> >> >
>> >> > SNIP
>> >> >
>> >> >> +     /*
>> >> >> +      * we do not consider an event that has not run as a good
>> >> >> +      * instance to mark a package as used (skip=1). Otherwise
>> >> >> +      * we may run into a situation where the first CPU in a package
>> >> >> +      * is not running anything, yet the second is, and this function
>> >> >> +      * would mark the package as used after the first CPU and would
>> >> >> +      * not read the values from the second CPU.
>> >> >> +      */
>> >> >> +     if (!(vals->run && vals->ena))
>> >> >> +             return 0;
>> >> >> +
>> >> >>       s = cpu_map__get_socket(cpus, cpu);
>> >> >>       if (s < 0)
>> >> >>               return -1;
>> >> >> @@ -235,7 +247,7 @@ process_counter_values(struct perf_stat_config *config, struct perf_evsel *evsel
>> >> >>       static struct perf_counts_values zero;
>> >> >>       bool skip = false;
>> >> >>
>> >> >> -     if (check_per_pkg(evsel, cpu, &skip)) {
>> >> >> +     if (check_per_pkg(evsel, aggr, cpu, &skip)) {
>> >> >
>> >> > should we pass 'count' instead o 'aggr' ?
>> >> >
>> >> the reason I passed counts_values is in case this function needs to be
>> >> called from other places which do
>> >> not use aggr mode.
>> >
>> > sure, but 'aggr' is being computed within process_counter_values
>> >
>> > process_counter_values gets 'count' argument with values read
>> > for given cpu/thread for further processing, and it seems to
>> > me that 'count' values should be passed to check_per_pkg
>> >
>> You do not want to aggregate values, you want to look at the individual events
>> for each CPU because you need to look at their run/ena fields.
>
> yes, but for 'count' not 'aggr'
>
Ah, yes, sorry, has to be count and not aggr. Sent the wrong version.
Can you fix it? Or do you want me to resubmit?

> jirka
>
>
> ---
> diff --git a/tools/perf/util/stat.c b/tools/perf/util/stat.c
> index f1d83599217b..2d065d065b67 100644
> --- a/tools/perf/util/stat.c
> +++ b/tools/perf/util/stat.c
> @@ -247,7 +247,7 @@ process_counter_values(struct perf_stat_config *config, struct perf_evsel *evsel
>         static struct perf_counts_values zero;
>         bool skip = false;
>
> -       if (check_per_pkg(evsel, aggr, cpu, &skip)) {
> +       if (check_per_pkg(evsel, count, cpu, &skip)) {
>                 pr_err("failed to read per-pkg counter\n");
>                 return -1;
>         }
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