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SubjectRe: perf report fractal output issue
On Fri, Oct 16, 2009 at 10:41:26AM +1100, Anton Blanchard wrote:
>
> Hi,
>
> > > It looks like callchain__fprintf_graph() only prints the callchain if we
> > > have at least one rb entry at the top. In my case all the associated
> > > backtraces are identical so I assume we dont have to do any splitting.
> >
> > Hmm, could you please send me a perf.data where you can see that?
> > Does that only happen on powerpc?
>
> I can replicate this on x86 by taking a perf.data and truncating it
> after the first sample+backtrace:
>
>
> # wget http://samba.org/~anton/perf_truncated.test
>
>
> # perf report -i perf_truncated.test -g fractal
> ...
> 100.00% perf [kernel] [k] native_write_msr_safe
>
>
> # perf report -i perf_truncated.test -g flat
> ...
> 100.00% perf [kernel] [k] native_write_msr_safe
> 100.00%
> native_write_msr_safe
> intel_pmu_enable_all
> hw_perf_enable
> perf_enable
> __perf_counter_enable
> smp_call_function_single
> task_oncpu_function_call
> perf_counter_enable
> perf_counter_for_each_child
> perf_ioctl
> vfs_ioctl
> do_vfs_ioctl
> sys_ioctl
> system_call_fastpath
> 0x7f00c1857537


Thanks, I can reproduce it with your file.
Actually it was there from the beginning but we have missed it:
the root of the callchain is never printed :-s

Say you have:

hist_entry
|
--------- f1
f2
|
-------- f3
| f4
|
---------f5
f6

Actually you never see that, instead you have:

hist_entry
|
--------- f3
| f4
|
--------- f5
f6

Thanks a lot for this report!
I'm currently fixing it.

I just hope the fix won't be too big for .32 ....



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