🚀 go-pugleaf

ROFL....

"athol" <athol_SPIT_SPAM@idl.net.au> wrote in message
news:1060325823.275932@webserver...
> In aus.computers.linux CyBorg_0091 <coldascoldx@netscape.net> wrote:
> > I was waiting for Hyperthreading and Linux
>
> Why wait?  Linux had it first...
>
> > Some XP kids are going to seriously ponder the meaning of life if they
read
> > your description.
>
> Except that his description is _wrong_.
>
> > Whats the point of hyperthreading if you can't see it!
>
> The Linux kernel makes the 2 hyperthreaded "processors" appear as
> separate processors.  If you had a box with an SMP motherboard
> with 2 HT processors, you'd have 4 virtual processors and that's
> what you'd see under linux.  HT _is_ virtual SMP and is treated
> as SMP by the kernel.  If you don't use an SMP kernel, you won't
> enable HT.
>
> In kernel 2.4, the 4 virtual processors would be essentially
> indistinguishable and a lightly loaded system could easily load
> the first 2 (ie the ones in one chip) with 2 heavy processes
> while the other 2 virtual processors (the other chip) are still
> just idling over.
>
> The 2.6 kernel is intended to provide "processor affinity", in
> which the kernel will know which virtual processors are in which
> processor and be able to intelligently allocate processes to
> processors in the most efficient possible manner.  This includes
> such things as putting processes that will use a lot of the same
> shared memory on the virtual processors within the same physical
> chip to maximise cache hits, putting an even amount of load on
> the separate physical processors in spite of low loads on 2nd
> hyperthreaded virtual processor of the first chip, etc...
>
> -- 
> Athol
> <http://cust.idl.com.au/athol>
> Linux Registered User # 254000
> I'm a Libran Engineer. I don't argue, I discuss.