On 2011-10-31 11:25, Robert P. J. Day wrote:
On Mon, 31 Oct 2011, Mark Hatle wrote:

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.

   that's what i would normally use, assuming that having an overly
high value for either of those settings can't possibly hurt.  if
that's the consensus, i can adjust the references to say 2x everywhere
that i know of.  just let me know.

Look back in the archives - I think it was Richard that did a fairly
extensive study of this and he (whoever it was) found that there were
saturation points and trying to get beyond them had a negative impact.

--
------------------------------------------------------------
Gary Thomas                 |  Consulting for the
MLB Associates              |    Embedded world
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