Re: perf report fractal output issue

From: Anton Blanchard
Date: Thu Oct 15 2009 - 19:45:40 EST



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
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