Messages in this thread | | | Subject | Re: [patch 0/4] perf_counter tools: support annotation of live kernel modules | From | Mike Galbraith <> | Date | Fri, 03 Jul 2009 10:00:58 +0200 |
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On Fri, 2009-07-03 at 09:29 +0200, Ingo Molnar wrote: > * Mike Galbraith <efault@gmx.de> wrote: > > > On Thu, 2009-07-02 at 09:17 +0200, Mike Galbraith wrote: > > > > > After I resurrect (well, try) live annotation in top... > > > > Random thought wrt live top annotation: instead of resurrecting in > > the previous form, which could be a bit intrusive display space > > wise, what do you think of this idea? > > > > Provide a kbd input snapshot trigger which builds a perf record > > (hard?) compatible file for the symbols being displayed. Start a > > background task to annotate the lot, stuffing annotate output into > > an output file. > > > > Better ideas highly welcome. > > Hm, is there really a performance problem?
Sort of..
> We need to calculate and cache the objdump annotation output once, > but after that it should be pretty fast as we just display updated > counts with the same lines over and over again. No repeated objdump > runs are needed.
But active files follow symbols, which change on the fly.
Besides, as mentioned previously, while displayed annotation was very cool, it took a lot of display space. For me, top with the ability to emit bic-disposable mini-reports would be my primary perf tools usage. I'd only use big brothers when I needed their power/detail.
-Mike
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