[meta-ti] poor performance of OpenEmbedded on BeagleBoneBlack compared to Debian

[Peter A. Bigot]

On 09/03/2014 09:46 PM, Robert Nelson wrote:
> On Wed, Sep 3, 2014 at 8:59 PM, Peter A. Bigot <pab at pabigot.com> wrote:
>> I've been trying to figure out why OpenEmbedded on beaglebone is three times
>> slower than Debian on the ray-tracing application described at:
>>
>> http://scruss.com/blog/2013/09/23/beaglebone-black-slow-as-a-dog/
>>
>> Part of it is due to meta-yocto-bsp's beaglebone config not enabling CPU
>> frequency control (CONFIG_GENERIC_CPUFREQ_CPU0, CONFIG_VOLTAGE_DOMAIN_OMAP,
>> and some THERMAL options).  That can be fixed for linux-yocto, and isn't an
>> issue with linux-ti-staging, but it doesn't eliminate the discrepancies.
>>
>> With debian, the sample program described in that blog posting runs this
>> fast:
>>
>>    debian at beaglebone:~$ g++ -Ofast -mfloat-abi=hard -o card card.cpp
>>    debian at beaglebone:~$ time ./card > /dev/null
>>    real    4m54.846s
>>    user    4m54.627s
>>    sys     0m0.057s
>>
>> With poky master + meta-ti it runs this fast:
>>
>>    root at beaglebone:~# time ./card > /dev/null
>>    real    9m37.901s
>>    user    9m37.200s
>>    sys     0m0.150s
> This seems very odd, what version of g++ do you have on poky?

4.9.1, also nothing special.

Peter

>
> On debian wheezy, we have the old:
>
> gcc version 4.6.3 (Debian 4.6.3-14)
>
> Which really doesn't have any of the linaro special sauce..
>
> Regards,
>