Re: [PATCH 1/3] perf tools: Record total sampling time

[Ingo Molnar <mingo@kernel.org>]

* Arnaldo Carvalho de Melo <acme@ghostprotocols.net> wrote:

> Em Mon, Dec 02, 2013 at 05:36:20PM +0100, Ingo Molnar escreveu:
> > * Namhyung Kim <namhyung@kernel.org> wrote:
> > > 2013-12-02 (월), 13:57 +0100, Ingo Molnar:
> > > > So basically, in the end I think it should be possible to have the 
> > > > following behavior:
> 
> > > >    perf record -a -e cycles sleep 1
> 
> > > >    perf report stat              # Reports as if we ran: 'perf stat -a -e cycles sleep 1'
> > > >    perf report                   # Reports the usual histogram
> 
> > > >    perf report --stat            # Reports the perf stat output and the histogram
> 
> > > > or so.
> 
> > > I don't think we need both of 'perf report stat' and 'perf report
> > > --stat'.  At least it looks somewhat confusing to users IMHO.
>  
> > Okay. Maybe the --stat option would be the more logical choice, 
> > because '--' options can be added arbitrarily, while it would be weird 
> > to add multiple subcommand options.
>  
> > So basically there would be two options:
>  
> >    --show-stat         [--no-show-stat]
> >    --show-histogram    [--no-show-histogram]
>  
> > Today --show-histogram is the only one enabled by default.
>  
> > Running:
>  
> >    perf report --no-show-histogram --show-stat
> 
> Why not:
> 
> perf stat -i perf.data
> 
> and make it be an optional argument, so plain:
> 
> perf stat -i
> 
> would process perf.data, i.e. would get the samples, accrue the periods,
> calculate the time, etc and then present it as 'perf stat <some
> target>'.
> 
> Right now 'perf stat -i' i used for '--no-inherit', perhaps we can just
> have --no-inherit have no short option and grab -i to have the same
> meaning as in 'report', 'script', etc.

Sounds good to me! It's (much) better than complicating the perf 
report UI with non-histogram formatting. perf record would have to be 
enhanced to make sure all events are 'perf stat' extractable by 
default, but that's it I think.

The only downside is that I now cannot get Namhyung to implement this 
nice feature as a side effect of the perf report feature he wants ;-)

Thanks,

	Ingo