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

[Peter A. Bigot]

On 09/04/2014 10:37 AM, Peter A. Bigot wrote:
> On 09/04/2014 10:00 AM, Denys Dmytriyenko wrote:
>> On Thu, Sep 04, 2014 at 02:50:03PM +0000, Mikhail Zakharov wrote:
>>> On Wed, Sep 3, 2014 at 8:59 PM, Peter A. Bigot <pab at pabigot.com> wrote:
>>>
>>>> One anomaly I've found is the CPU frequency range.  On debian we have:
>>>>
>>>>     debian at beaglebone:~$ cat
>>>> /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies
>>>>     300000 600000 800000 1000000
>>>>
>>>> while on OE we have:
>>>>
>>>>     root at beaglebone:~# cat
>>>> /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies
>>>>     300000 600000 720000 800000
>>> Stock yocto-bsp is missing a few things that can be found in Robert
>>> Nelson's patchset for 3.14 linux kernel.
>>>
>>> There are lots of other functionality that is missing from yocto-bsp
>>> kernel for Beaglebone. I suggest you take at the following repos and
>>> scavenge for what you need :P
>> First of all, this is meta-ti mailing list for the corresponding BSP. 
>> That's
>> what Peter was asking for, comparing to Robert's Debian and Yocto 
>> reference
>> BSPs, not the other way around.
>>
>> Second, Yocto reference BSP is that way for a reason - it's a 
>> reference BSP
>> done with pure mainline kernel and u-boot components w/o any patching 
>> on top.
>> That's its entire purpose. For anything else special, including 
>> performance
>> tweaks, there are other BSPs available. If there is an issue with 
>> performance
>> in meta-ti, we'll investigate it and try to match with Robert's BSP.
>
> Yes, at this time meta-ti's BSP performs as well as I've seen any 
> OE-based system, and gets several things right that meta-yocto-bsp 
> does not (and one thing wrong that meta-yocto-bsp gets right, I think; 
> still investigating, will follow-up when I'm sure).
>
> I've also verified that performance with a native gcc 4.9.1 build on 
> BeagleBone with hard float is poor, so it's not due to the way OE 
> builds gcc.  I have several competing hypotheses to test.
>
> But I'm still looking for a way to set the CPU frequency to the higher 
> values supported on Beaglebone Black.  I had hoped meta-ti's would be 
> able to do that, since it has bone vs boneblack device trees and 
> u-boot detection.
>
> Any hints where to look for clock settings?
>

Apologies; I didn't read Mikhail's full email before responding. Thanks 
for the links; I'll check those out, and maybe provide meta-ti patches 
so this gets fixed at the "source".

Peter