Re: [PATCH 2/2] perf callchain: Use global caching provided by libunwind

[Namhyung Kim <namhyung@kernel.org>]

Hi Jean,

On Fri, 26 Sep 2014 09:14:41 +0200, Jean Pihet wrote:
> Hi,
>
> On 26 September 2014 07:50, Namhyung Kim <namhyung@kernel.org> wrote:
>> Hi Jean,
>>
>> On Wed, 24 Sep 2014 15:45:57 +0200, Jean Pihet wrote:
>>> Hi!
>>>
>>> Here are the test results on ARMv7 for the 2 patches. The speedup is
>>> about x2.1 for identical unwinding output data.
>>>
>>> 'perf record --call-graph dwarf -- stress --cpu 2 --io 2 --vm 2
>>> --timeout 10s' generates a 365 MB perf.data file.
>>>
>>> time perf.orig report --sort symbol --call-graph --stdio 2&>1 > /dev/null
>>> average on 3 runs
>>> real    36.736
>>> user   14.79
>>> sys    21.91
>>>
>>> time perf.libunwind.speedup report --sort symbol --call-graph --stdio
>>> 2&>1 > /dev/null
>>> average on 3 runs
>>> real    17.41        x2.11
>>> user     6.42        x2.3
>>> sys    10.97        x2
>>>
>>> So the patches definitely speedup the unwinding.
>>> FWIW: Acked-by: Jean Pihet <jean.pihet@linaro.org>
>>
>> Thanks for your test!
>>
>> Btw, have you checked the difference of the output before and after the
>> caching?
> Yes the output is identical (as stated here above).

Ah, I misunderstood it.  Thanks for your confirmation. :)

Thanks,
Namhyung