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

From: Jiri Olsa
Date: Wed Mar 02 2016 - 06:28:51 EST


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