Re: [PATCHSET 00/12] perf tools: Apply percent-limit to callchains

From: Jiri Olsa
Date: Tue Jan 26 2016 - 08:27:36 EST


On Tue, Jan 26, 2016 at 09:51:59PM +0900, Namhyung Kim wrote:
> On Tue, Jan 26, 2016 at 01:14:47PM +0100, Jiri Olsa wrote:
> > On Sun, Jan 24, 2016 at 10:53:23PM +0900, Namhyung Kim wrote:
> > > Hello,
> > >
> > > This patchset tries to implement percent limit to callchains which was
> > > requested by Andi Kleen. For some reason, limiting callchains by
> > > (overhead) percentage didn't work well. This patch fixes it and make
> > > --percent-limit also works for callchains as well as hist entries.
> > >
> > > This is available on 'perf/callchain-limit-v1' branch in my tree:
> > >
> > > git://git.kernel.org/pub/scm/linux/kernel/git/namhyung/linux-perf.git
> > >
> > > Any comments are welcome,
> > >
> > > Thanks,
> > > Namhyung
> > >
> > >
> > > Namhyung Kim (12):
> > > perf report: Apply --percent-limit to callchains also
> > > perf report: Apply callchain percent limit on --stdio
> > > perf report: Get rid of hist_entry__callchain_fprintf()
> > > perf report: Fix percent calculation on --stdio
> > > perf report: Hide output pipe for percent-limited callchains on stdio
> > > perf hists browser: Fix dump to show correct callchain style
> > > perf hists browser: Fix callchain_node__count_rows()
> > > perf hists browser: Apply callchain percent limit
> > > perf hists browser: Fix callchain counting when press ENTER key
> > > perf hists browser: Fix counting callchains when expand/collapse all
> > > perf hists browser: Update percent base for fractal callchain mode
> > > perf report: Fix callchain percent limit on --gtk
> >
> > is 0.5 the default or one has to use the --percent-limit 0.5
> > for the limit to be effective?
>
> Yes, it's effective now. I also think we need to change the default
> limit of 0.5. It was set for 'fractal' mode initially AFAIK so its
> percentage is relative to each node. In this case 0.5% of limit makes
> sense because it'll be a very small (absolute) value.
>
> But With 'graph' mode (now default), there're many entries under 0.5
> overhead and they silently won't show callchains anymore. Actually I
> was confused by it when working with this patchset.
>
> What about 0.005% for the new default?
>
>
> >
> > without the option I'm getting empty callchains that are below 0.5
> > but only in TUI mode (attached).. --stdio shows them all unfolded
>
> It should not show them all. But I found that I missed a check for
> a stdio case. Could you please test below?

did not help, it's still there.. same output as before

jirka