Re: [PATCH 5/7] perf, tools, stat: Implement --metric-only mode

[Jiri Olsa]

On Tue, Mar 01, 2016 at 01:32:39PM +0100, Jiri Olsa wrote:
> On Mon, Feb 29, 2016 at 02:36:24PM -0800, Andi Kleen wrote:
> > From: Andi Kleen <ak@xxxxxxxxxxxxxxx>
> > 
> > Add a new mode to only print metrics. Sometimes we don't care about
> > the raw values, just want the computed metrics. This allows more
> > compact printing, so with -I each sample is only a single line.
> > This also allows easier plotting and processing with other tools.
> > 
> > The main target is with using --topdown, but it also works with
> > -T and standard perf stat. A few metrics are not supported.
> > 
> > To avoiding having to hardcode all the metrics in the code it uses
> > a two pass approach: first compute dummy metrics and only
> > print the headers in the print_metric callback. Then use the callback
> > to print the actual values.
> > 
> > There are some additional changes
> > in the stat printout code to handle all metrics being on a single line.
> > 
> > One issue is that the column code doesn't know in advance what events
> > are not supported by the CPU, and it would be hard to find out
> > as this could change based on dynamic conditions. That causes
> > empty columns in some cases.
> > 
> > The output can be fairly wide, often you may need more than 80 columns.
> > 
> > Example:
> > 
> > % perf stat -a -I 1000 --metric-only
> >      1.001452803 frontend cycles idle insn per cycle       stalled cycles per insn branch-misses of all branches
> >      1.001452803  158.91%               0.66                2.39                    2.92%
> >      2.002192321  180.63%               0.76                2.08                    2.96%
> >      3.003088282  150.59%               0.62                2.57                    2.84%
> >      4.004369835  196.20%               0.98                1.62                    3.79%
> >      5.005227314  231.98%               0.84                1.90                    4.71%
> 
> could you please align values with the headers

you addressed this in new version

> 
> also I have same issue with the stalled cycles
> being printed as empty in here:
> 
> [jolsa@krava perf]$ sudo ./perf stat -a -I 1000 --metric-only
>      1.000583845 insn per cycle       stalled cycles per insn branch-misses of all branches 
>      1.000583845    0.45                                         4.55%                      
>      2.001055181    0.86                                         4.06%                      
>      3.001262956    0.63                                         3.59%                      

but not this one..

jirka