Re: [PATCH 3/7] perf, tools, stat: Support metrics in --per-core/socket mode

[Andi Kleen <andi@firstfloor.org>]

On Tue, Mar 01, 2016 at 01:31:49PM +0100, Jiri Olsa wrote:
> On Mon, Feb 29, 2016 at 02:36:22PM -0800, Andi Kleen wrote:
> > From: Andi Kleen <ak@linux.intel.com>
> > 
> > Enable metrics printing in --per-core / --per-socket mode. We need
> > to save the shadow metrics in a unique place. Always use the first
> > CPU in the aggregation. Then use the same CPU to retrieve the
> > shadow value later.
> > 
> > Example output:
> > 
> > % perf stat --per-core -a ./BC1s
> > 
> >  Performance counter stats for 'system wide':
> > 
> > S0-C0           2        2966.020381      task-clock (msec)         #    2.004 CPUs utilized            (100.00%)
> > S0-C0           2                 49      context-switches          #    0.017 K/sec                    (100.00%)
> > S0-C0           2                  4      cpu-migrations            #    0.001 K/sec                    (100.00%)
> > S0-C0           2                467      page-faults               #    0.157 K/sec
> > S0-C0           2      4,599,061,773      cycles                    #    1.551 GHz                      (100.00%)
> > S0-C0           2      9,755,886,883      instructions              #    2.12  insn per cycle           (100.00%)
> > S0-C0           2      1,906,272,125      branches                  #  642.704 M/sec                    (100.00%)
> > S0-C0           2         81,180,867      branch-misses             #    4.26% of all branches
> > S0-C1           2        2965.995373      task-clock (msec)         #    2.003 CPUs utilized            (100.00%)
> > S0-C1           2                 62      context-switches          #    0.021 K/sec                    (100.00%)
> > S0-C1           2                  8      cpu-migrations            #    0.003 K/sec                    (100.00%)
> > S0-C1           2                281      page-faults               #    0.095 K/sec
> > S0-C1           2          6,347,290      cycles                    #    0.002 GHz                      (100.00%)
> > S0-C1           2          4,654,156      instructions              #    0.73  insn per cycle           (100.00%)
> > S0-C1           2            947,121      branches                  #    0.319 M/sec                    (100.00%)
> > S0-C1           2             37,322      branch-misses             #    3.94% of all branches
> > 
> >        1.480409747 seconds time elapsed
> > 
> > v2: Rebase to older patches
> > v3: Document shadow cpus. Fix aggr_get_id argument. Fix -A shadows (Jiri)
> > Signed-off-by: Andi Kleen <ak@linux.intel.com>
> > ---
> >  tools/perf/builtin-stat.c     | 61 +++++++++++++++++++++++++++++++++++++------
> >  tools/perf/util/stat-shadow.c |  7 +++++
> >  2 files changed, 60 insertions(+), 8 deletions(-)
> > 
> > diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
> > index 2ffb822..c79e571 100644
> > --- a/tools/perf/builtin-stat.c
> > +++ b/tools/perf/builtin-stat.c
> > @@ -740,6 +740,8 @@ struct outstate {
> >  	bool newline;
> >  	const char *prefix;
> >  	int  nfields;
> > +	int  id, nr;
> > +	struct perf_evsel *evsel;
> >  };
> >  
> >  #define METRIC_LEN  35
> > @@ -755,12 +757,9 @@ static void do_new_line_std(struct outstate *os)
> >  {
> >  	fputc('\n', os->fh);
> >  	fputs(os->prefix, os->fh);
> > +	aggr_printout(os->evsel, os->id, os->nr);
> >  	if (stat_config.aggr_mode == AGGR_NONE)
> >  		fprintf(os->fh, "        ");
> 
> any reason for this extra space for AGGR_NONE?

It's just to avoid special cases for NONE elsewhere, as it has
the same alignment.  This was there before.

-Andi