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

[Robert Nelson]

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?

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,

-- 
Robert Nelson
http://www.rcn-ee.com/