Re: callchain sampling bug in perf?

From: Christoph Hellwig
Date: Fri Aug 20 2010 - 05:16:52 EST


On Thu, Aug 19, 2010 at 12:04:22PM -0300, Arnaldo Carvalho de Melo wrote:
>
> [acme@doppio tmp]$ perf report
>
> http://vger.kernel.org/~acme/perf/perf-report-tui-callchain-xlog_sync.png
>
> So it seems to work (you tell me if the callchains make sense), and the problem

I've rebuilt perf with libnewt to reproduce it, but to get any of the
callchain data I need to call perf report with a -g argument (which is
rather expected from the documentation anyway)

I still see the same problems as with the TUI perf report with that.
With the -g {mode},0.0 there is nothing to expand inside the GUI for
e.g. the pythong process, and with the 0.0 threshold I can only expand
a few 0.<something> callchains, but I never see the 80% your screenshot
shows. What perf version are you running?

Also the flat mode is rendered incorrectly, it just adds different call
graphs inside a single process directly after each other instead of
separating them in the rendering.


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