Intel Core Duo. SMP kernel but still only 50% load while using make on ports...

Daniel Tourde daniel.tourde at
Thu Feb 8 22:04:01 UTC 2007

Hello Bill, 

Thanks for your answer

> >    I have at my disposal an Inspiron 9400 with an Intel Core    FreeBSD
> 6.2
> > is installed and rebuilt to fit the processor. The kerne   l is in SMP
> mode.
> >    I noticed something strange: When I compile using ma   in the ports
> > tree, I only have 50% load. CPU1 is used at   CPU0 is idle...
> How do you know this?

With 'top'

> >    I tried make -j2 but it did not work,   Any idea?
> -j2 does not guarantee that you'll use both CPUs.  It's entirely possible
> that the IO is slow enough that both of the processes are waiting on disk
> and only able to push the overall system usage to 50%.  Try make -j99.
> Also, there are places in the build process where it's only possible to
> run one process at a time, so you can't just take a single snapshot of
> it, you have to watch it over time.

I think it's more that the port tree does not really like parallel processes...

> I'm still not convinced anything is wrong:
> *) Does dmesg show the second CPU starting?


> *) Does top show a column for CPU binding?  Are different processes bound
>    to different CPUs?


> *) Are these hyperthreaded CPUs?  If so, is hyperthreading enabled?  HT is
>    disabled by default on FreeBSD, and overall usage will never go above
>    50% if HT is off.

No, it's a Dual Core


Förena nytta med nöje. Koppla av och ha kul samtidigt som du har chansen att vinna pengar på din skicklighet. På Spray spel kan du tävla mot andra och den som är bäst kan vinna mycket pengar. Till spelen:

More information about the freebsd-questions mailing list