Problem on AMD64

Ian Smith smithi at nimnet.asn.au
Sat Dec 27 18:20:29 PST 2008


On Sat, 27 Dec 2008, Alexandre "Sunny" Kovalenko wrote:
 > On Sat, 2008-12-27 at 17:13 +1100, Ian Smith wrote:
 > > On Fri, 26 Dec 2008, Garrett Cooper wrote:
 > >  > On Thu, Dec 25, 2008 at 1:14 AM, David van Kuijk <dynasore at bigfoot.com> wrote:
 > >  [..]
 > >  > >> Look into the following sysctls:
 > >  > >>
 > >  > >> hw.acpi.cpu.cx_lowest
 > >  > >> hw.acpi.cpu.cx_highest
 > >  > >>
 > >  > >
 > >  > > I tried to find out what I can do with those sysctls.
 > >  > > hw.acpi.cpu.cx_highest is not available on my system.
 > > 
 > > I don't think it exists; C1 state is always available AFAIK.
 > > 
 > >  > > hw.acpi.cpu.cx_lowest is available and can be set. Are you suggesting I
 > >  > > should set it to C2 or C3???
 > > 
 > > Give it a try.  Setting it to C3 won't hurt, whether it's used or not.  

 > Actually it just might (hurt that is). See below for the discussion.
 > 
 > http://www.freebsd.org/cgi/getmsg.cgi?fetch=0+2482
 > +/usr/local/www/db/text/2008/freebsd-acpi/20081109.freebsd-acpi

Thanks.  Yes that was indeed an interesting discussion.  FWIW, I find 
that interface awkward, without threading.  For me it's easier from:
http://lists.freebsd.org/pipermail/freebsd-acpi/2008-November/005182.html

Could I then safely say, setting it to C2 won't hurt?

I'm glad there are folks working on power use with SMP, it still needs 
moving up the agenda.  'Global notebook sales finally beat desktops': 
http://www.theregister.co.uk/2008/12/24/notebooks_pass_desktops/

Soon it'll be hard to find uniprocessors even on subnotebooks; has 
anyone played with the new Intel Atom CPUs, which use HTT on one core?

And to mix topics further, having USB enabled looks problematic with 
on-battery use of laptops .. does this new USB stack offer any relief?

cheers, Ian


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