Re: PARALLEL_MAKE

[Denys Dmytriyenko <denis@denix.org>]

On Thu, Mar 12, 2009 at 06:38:54PM -0700, Khem Raj wrote:
> On Thursday 12 March 2009 16:32:16 Ulf Samuelsson wrote:
> > Is there any activity to make this more useful?
> > Just managed to install a Core i7 machine, which speeded
> > up my Buildroot build from about 4 hours to less than 1 hour.
> > (There was an error in the build right at the end,
> > so it could have been downto 40 minutes or so)
> > Building the cross compiler took 10 minutes with "make -j 16"
> > compared to 1-2 hours on a P4 @ 3GHz.
> >
> > Openembedded does not seem to use PARALLEL_MAKE extensively.
> > I have the frequency meter activated for all 8 CPUs in the Core i7,
> > and most of the time the CPUs seems to idle at 1.6 GHz,
> > with one CPU (or rarely 2) are running at the full 2.67 GHz.
> >
> > Last time I built OE on a P4@ 3 GHz it took ~40 hours
> > for the SAM9263, so some speedup would be nice.
> > Maybe we should make an effort?
> 
> I use 
> 
> PARALLEL_MAKE = "-j4" 
> BB_NUMBER_THREADS = "2"
> 
> in my local.conf. I see my core 2 duo machine spawning parallel tasks.

I'm setting 4/4 to the above two variables on my Quad Core and it loads all 4 
cores at 100% almost all the time. Sometimes it slows down due to the 
bottleneck in the harddrive access...

-- 
Denys