Re: [PATCH 2/6] perf, tools, stat: Implement CSV metrics output

[Andi Kleen]

On Sun, Feb 21, 2016 at 05:39:40PM +0100, Jiri Olsa wrote:
> On Thu, Feb 18, 2016 at 06:39:21PM +0100, Andi Kleen wrote:
> > > Where before it wasn't there:
> > > 
> > > cat /tmp/before
> > > 0.282628,,task-clock,282628,100.00
> > > 1,,context-switches,282628,100.00
> > > 0,,cpu-migrations,282628,100.00
> > > 52,,page-faults,282628,100.00
> > > 861213,,cycles,285354,100.00
> > > <not supported>,,stalled-cycles-frontend,0,100.00
> > > <not supported>,,stalled-cycles-backend,0,100.00
> > > 686082,,instructions,285354,100.00
> > > 137846,,branches,285354,100.00
> > > 7142,,branch-misses,285354,100.00
> > 
> > This is intentional. See the standard perf output:
> > 
> > 
> >           521,232      instructions              #    0.63  insns per cycle        
> >                                                  #    1.13  stalled cycles per insn
> > 
> > So this line has multiple metrics. In CSV this is expressed as a mostly empty line.
> 
> it's intentional if you have data from stalled cycles counter
> on cpu where this one is non supported you get blank line:

I fixed this now by probing for the stalled cycles counters in advance.
That avoids a couple of other issues too, like the empty columns in
--metric-only, and even makes the output of standard perf stat
shorter.

-Andi