what's the proper value for BB_NUMBER_THREADS?

what's the proper value for BB_NUMBER_THREADS?

[Robert P. J. Day]

  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?

rday

-- 

========================================================================
Robert P. J. Day                                 Ottawa, Ontario, CANADA
                        http://crashcourse.ca

Twitter:                                       http://twitter.com/rpjday
LinkedIn:                               http://ca.linkedin.com/in/rpjday
========================================================================

Re: what's the proper value for BB_NUMBER_THREADS?

[Christian Gagneraud]

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.

Chris


>
> rday
>


-- 
Chris

Re: what's the proper value for BB_NUMBER_THREADS?

[Robert P. J. Day]

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

-- 

========================================================================
Robert P. J. Day                                 Ottawa, Ontario, CANADA
                        http://crashcourse.ca

Twitter:                                       http://twitter.com/rpjday
LinkedIn:                               http://ca.linkedin.com/in/rpjday
========================================================================

Re: 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

Re: what's the proper value for BB_NUMBER_THREADS?

[Robert P. J. Day]

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.

rday

-- 

========================================================================
Robert P. J. Day                                 Ottawa, Ontario, CANADA
                        http://crashcourse.ca

Twitter:                                       http://twitter.com/rpjday
LinkedIn:                               http://ca.linkedin.com/in/rpjday
========================================================================

Re: what's the proper value for BB_NUMBER_THREADS?

[Gary Thomas]

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
------------------------------------------------------------

Re: what's the proper value for BB_NUMBER_THREADS?

[Darren Hart]

On 10/31/2011 10:39 AM, Gary Thomas wrote:
> 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.

2x on each works well up to about 12 in my experience. Richard has found
benefits using 24 on a similar system with more memory. However, if you
aren't building on a monster machine, then 2x serves as a reasonable
rule of thumb.

-- 
Darren Hart
Intel Open Source Technology Center
Yocto Project - Linux Kernel

Re: what's the proper value for BB_NUMBER_THREADS?

[Robert P. J. Day]

On Thu, 3 Nov 2011, Darren Hart wrote:

>
>
> On 10/31/2011 10:39 AM, Gary Thomas wrote:
> > 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.
>
> 2x on each works well up to about 12 in my experience. Richard has found
> benefits using 24 on a similar system with more memory. However, if you
> aren't building on a monster machine, then 2x serves as a reasonable
> rule of thumb.

  since i vaguely recall that i was the one who asked about this, i
can submit a patch for this unless someone else already wants to.  i
can see that the places to change would be in some of the docs, as
well as the comment in local.conf.sample.

  anyone else want to take care of that?  anyone?  bueller?

rday

-- 

========================================================================
Robert P. J. Day                                 Ottawa, Ontario, CANADA
                        http://crashcourse.ca

Twitter:                                       http://twitter.com/rpjday
LinkedIn:                               http://ca.linkedin.com/in/rpjday
========================================================================

Re: what's the proper value for BB_NUMBER_THREADS?

[Rifenbark, Scott M]

I haven't heard more on this.  Should I adjust the documents to suggest 2x for both these variables?

Scott

-----Original Message-----
From: yocto-bounces@yoctoproject.org [mailto:yocto-bounces@yoctoproject.org] On Behalf Of Robert P. J. Day
Sent: Thursday, November 03, 2011 10:42 AM
To: Darren Hart
Cc: yocto@yoctoproject.org
Subject: Re: [yocto] what's the proper value for BB_NUMBER_THREADS?

On Thu, 3 Nov 2011, Darren Hart wrote:

>
>
> On 10/31/2011 10:39 AM, Gary Thomas wrote:
> > 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.
>
> 2x on each works well up to about 12 in my experience. Richard has found
> benefits using 24 on a similar system with more memory. However, if you
> aren't building on a monster machine, then 2x serves as a reasonable
> rule of thumb.

  since i vaguely recall that i was the one who asked about this, i
can submit a patch for this unless someone else already wants to.  i
can see that the places to change would be in some of the docs, as
well as the comment in local.conf.sample.

  anyone else want to take care of that?  anyone?  bueller?

rday

-- 

========================================================================
Robert P. J. Day                                 Ottawa, Ontario, CANADA
                        http://crashcourse.ca

Twitter:                                       http://twitter.com/rpjday
LinkedIn:                               http://ca.linkedin.com/in/rpjday
========================================================================
_______________________________________________
yocto mailing list
yocto@yoctoproject.org
https://lists.yoctoproject.org/listinfo/yocto

Re: what's the proper value for BB_NUMBER_THREADS?

[Darren Hart]

On 11/15/2011 03:08 PM, Rifenbark, Scott M wrote:
> I haven't heard more on this.  Should I adjust the documents to
> suggest 2x for both these variables?

I think that's a reasonable thing to do, yes.

--
Darren

> 
> Scott
> 
> -----Original Message----- From: yocto-bounces@yoctoproject.org
> [mailto:yocto-bounces@yoctoproject.org] On Behalf Of Robert P. J.
> Day Sent: Thursday, November 03, 2011 10:42 AM To: Darren Hart Cc:
> yocto@yoctoproject.org Subject: Re: [yocto] what's the proper value
> for BB_NUMBER_THREADS?
> 
> On Thu, 3 Nov 2011, Darren Hart wrote:
> 
>> 
>> 
>> On 10/31/2011 10:39 AM, Gary Thomas wrote:
>>> 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.
>> 
>> 2x on each works well up to about 12 in my experience. Richard has
>> found benefits using 24 on a similar system with more memory.
>> However, if you aren't building on a monster machine, then 2x
>> serves as a reasonable rule of thumb.
> 
> since i vaguely recall that i was the one who asked about this, i can
> submit a patch for this unless someone else already wants to.  i can
> see that the places to change would be in some of the docs, as well
> as the comment in local.conf.sample.
> 
> anyone else want to take care of that?  anyone?  bueller?
> 
> rday
> 

-- 
Darren Hart
Intel Open Source Technology Center
Yocto Project - Linux Kernel