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

From: Ingo Molnar
Date: Wed Dec 04 2013 - 05:02:35 EST



* Arnaldo Carvalho de Melo <acme@xxxxxxxxxxxxxxxxxx> wrote:

> Em Mon, Dec 02, 2013 at 05:36:20PM +0100, Ingo Molnar escreveu:
> > * Namhyung Kim <namhyung@xxxxxxxxxx> wrote:
> > > 2013-12-02 (ì), 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
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