[yocto] what's the proper value for BB_NUMBER_THREADS?

[Mark Hatle]

On 10/30/11 11:15 AM, Robert P. J. Day wrote:
> On Sun, 30 Oct 2011, Christian Gagneraud wrote:
> 
>> On 30/10/11 15:32, Robert P. J. Day wrote:
>>>
>>>    all the docs recommend twice the number of cores (AFAICT), yet the
>>> template local.conf file suggests that, for a quad core, the value of
>>> 4 would be appropriate.  shouldn't that say 8?  same with
>>> PARALLEL_MAKE?
>>
>> Hi Robert,
>>
>> The Poky ref manual says (rule of thumb) x2 for BB_NUMBER_THREADS,
>> and x1.5 for PARALLEL_MAKE.
> 
>   if that's the case, anyone object to my submitting a patch to
> update local.conf.sample appropriately?
> 
> rday
> 

I agree the manual and local.conf files should match.  The issue seems to be
that the perfect values are subjective.  Things like memory, disk speed, chipset
latency, and of course processor speed/cores all affect the optimal setting.
But we do need a consistent rule of thumb..  I myself usually use x2 for both
THREADS and MAKE.

--Mark