[Tfug] Dual cores and hyperthreading

[John Sonderegger]

With Ubuntu, the 686 kernel has smp enabled and the 386
kernel does not.  

I'm running a T2300 notebook with the 686 kernel and can
use ksysguard to see the work load on each of the cores.

For somebody with lots of windows open (I've been running 3
instances of pdf readers on a 22 mb pdf file wit lots of
graphics [includes rescaling]) and think the the 686 kernel
is helping me.

John

--- John Gruenenfelder <johng at as.arizona.edu> wrote:

> Hey all,
> 
> I've got a hardware question about dual cores and
> hyperthreading.  My new
> laptop has a core duo chip inside.  To utilize both
> cores, all you need is a
> SMP kernel.  Easy enough.
> 
> But, the core duo is also based on the Pentium 4m which
> supports
> hyperthreading.  This is confirmed by running cpuid:
> 
> ---------
> Extended brand string: "Genuine Intel(R) CPU          
> T2400  @ 1.83GHz"
> CLFLUSH instruction cache line size: 8
> Initial APIC ID: 1
> Hyper threading siblings: 2
> 
> Feature flags bfe9fbff:
> ...
> SS     Self Snoop
> HT     Hyper Threading
> TM     Thermal monitor
> ...
> ---------
> 
> Is is possible to take advantage of this as well?  My
> understanding is that
> hyperthreading is 2 virtual CPUs in a single core and so
> it should be separate
> from the hardware which enables two physical cores thus
> making it possible to
> use both at the same time.
> 
> Last time I used a HT capable machine in Linux (a while
> ago), I didn't need
> anything extra other than an SMP kernel.
> 
> Am I confused about the situation?  Maybe I need
> additional support from
> elsewhere in the machine like the BIOS (I already looked
> in there)?
> 
> 
> -- 
> --John Gruenenfelder    Research Assistant, UMass Amherst
> student
>                         Systems Manager, MKS Imaging
> Technology, LLC.
> Try Weasel Reader for PalmOS  --  http://gutenpalm.sf.net
> "This is the most fun I've had without being drenched in
> the blood
> of my enemies!"
>         --Sam of Sam & Max
> 
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John Sonderegger   jsonder at yahoo.com
http://members.cox.net/jsonder59
Transported by Tigger or Tux
Nekid bikes feel faster

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