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

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Message-ID: <CABPqkBSMSBYpcwODbYxQ5n9y7MtT03aMgwO0fQQLQ-A7fdSJkA@mail.gmail.com>
Date:	Thu, 3 Sep 2015 05:05:32 -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 5:01 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.
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