Re: perf report fractal output issue

From: Frederic Weisbecker
Date: Thu Oct 15 2009 - 08:31:30 EST


On Thu, Oct 15, 2009 at 09:57:26AM +1100, Anton Blanchard wrote:
>
> Hi,
>
> I noticed a problem where I wasn't always getting callchains:
>
> # perf report
> 98.47% lock1_processes [kernel] [k] .lock_kernel
>
> 0.91% lock1_processes [kernel] [k] .fput
>
>
> But a flat output confirmed the data is there:
>
> # perf report -g flat
> 98.47% lock1_processes [kernel] [k] .lock_kernel
> 98.47%
> .lock_kernel
> .__posix_lock_file
> (nil)
> .fcntl_setlk
> .sys_fcntl
> syscall_exit
> 0xfffb7d04844
> .testcase
> .testcase
> .affinitize
> .new_task
> .main
> 0xfffb7c4933c
> 0xfffb7c4955c
> (nil)
>
> 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.
>
> Anton


Hmm, could you please send me a perf.data where you can see that?
Does that only happen on powerpc?


Thanks.

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