dolfin team mailing list archive

[Anders Logg <logg@xxxxxxxxx>]

On Wed, Oct 17, 2012 at 10:48:37AM -0500, Anders Logg wrote:
> On Wed, Oct 17, 2012 at 10:32:58AM -0500, Anders Logg wrote:
> > On Wed, Oct 17, 2012 at 07:56:05AM +0200, Johannes Ring wrote:
> > > On Wed, Oct 17, 2012 at 6:52 AM, Anders Logg <logg@xxxxxxxxx> wrote:
> > > > On Wed, Oct 17, 2012 at 06:38:14AM +0200, Johannes Ring wrote:
> > > >> On Wed, Oct 17, 2012 at 6:15 AM, Anders Logg <logg@xxxxxxxxx> wrote:
> > > >> > I'm having trouble building ATLAS. It seems to believe I have CPU
> > > >> > throttling disabled, although I've set the CPU frequency to its
> > > >> > maximum for all my cores and set the 'governor' to 'performance'.
> > > >> >
> > > >> > The commands in question are
> > > >> >
> > > >> >  sudo cpufreq-set -c $i -u $MAX_FREQ
> > > >> >  sudo cpufreq-selector -g performance -c $i
> > > >> >
> > > >> > for each processor $i.
> > > >> >
> > > >> > Any ideas how to fix this?
> > > >>
> > > >> What is set in your
> > > >> /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor? If it is not
> > > >> 'performance', try changing it directly instead of using cpufrequtils:
> > > >>
> > > >>   sudo sh -c "echo performance >
> > > >> /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor"
> > > >>
> > > >> Do the same for the other CPU's.
> > > >
> > > > That's the strange thing. All 8 of those files already say
> > > > 'performance'.
> > > >
> > > > Does it work on your machine if you run
> > > >
> > > >   ./dorsal.sh FEniCS/platforms/contributed/precise-hpc.platform
> > >
> > > It looks ok for me. No errors and it is compiling now. I got "Cannot
> > > detect CPU throttling" but I'm not sure if that's good or bad.
> >
> > ok good.
> >
> > > BTW, I commented out the part in atlas.package where you change the
> > > frequency and governor because I already had it set to 'performance'.
> >
> > I've made it optional now.
> >
> > The strange this is all my CPUs are running at full speed but ATLAS
> > still thinks I have throttling on. I've also tried changing in BIOS.
> >
> > Does anyone know if there's an option to turn off the throttling check
> > in ATLAS?
>
> ok, so messing with the cpufreq-functions does not seem to help at
> all. ATLAS will still think I have throttling enabled.
>
> What I did now was to disable "Intel speedstep technology" in BIOS
> (tried various other options first like setting to "maximum
> performance") but that didn't help.
>
> Then the cpufreq-functions can't be used, the processor runs at
> 2.49GHz (as opposed to 2.50Ghz when scaled up full with speedstep
> enabled), and ATLAS does not detect throttkling and configures
> happily.

Note for future reference: ATLAS build with Dorsal takes ca 9 min on
my laptop so it's relatively easy and quick to build.

--
Anders