Re: State of "perf: Add a new sort order: SORT_INCLUSIVE"

From: Frederic Weisbecker
Date: Tue Oct 29 2013 - 04:37:16 EST


On Mon, Oct 28, 2013 at 09:10:38PM -0700, Arun Sharma wrote:
> On 10/28/13 8:11 PM, Namhyung Kim wrote:
>
> Hey Namhyung:
>
> >>
> >>Also, what's the reasoning for --cumulate not being an option under
> >>perf record -g ..,<order>?
> >
> >Sorry, I cannot understand you. The 'perf record' just saves sample
> >data (and callchains) from the ring-buffer. All the processing happens
> >in 'perf report'. I can't see what you expect from the 'perf record
> >--cumulate'. Am I missing something?
>
> Yes - I meant to say perf report -g :)
>
> > -g [type,min[,limit],order]
>
> Specifically, along with callee, caller, we could have a third
> option. Or we could have a new type (graph, fractal, cumulative).
>
> >>Given that there are clear use cases in production involving complex
> >>callgraphs, I'm for getting this support in first and then reconciling
> >>the differences with perf record -b later.
> >
> >I think what Frederic said is that the code de-duplication of 'perf
> >report' side. The branch stack and --cumulate are different - branch
> >stack concentrates on the branch itself but --cumulate uses callchains
> >to find parents and give some credit to them as side information.
>
> Me too. I brought it up with Stephane at some point in the last year
> or so and there wasn't an obvious way to de-duplicate because of
> these differences.

I agree that the interface is debatable. It could be -g ...,cumulative, expand -b, or whatever.
But the backend is the same: perf_report__add_branch_hist_entry should be shared 80%.
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