Re: SMP

[Phil Brutsche <pbrutsch@creighton.edu>]

A long time ago, in a galaxy far, far way, someone said...

> On Wed, 16 Feb 2000, Phil Brutsche wrote:
> > It's conceivable that the BIOS would enable it's SMP support when the
> > second CPU card in added.  It's also possible that there was BIOS on the
> > CPU card that 'patched' (somehow) the motherboard's BIOS.
> 
> I see, so it's worth trying.
> I think the best way is to insert the second CPU board into the slot and
> boot the machine, right...?

Trying it is the best way of finding out.  Just keep in mind that pretty
much any 486 is slow, and adding a second processor will mean that it's
still slower than a Pentium.

> BTW, more /proc/interrupts says:
> bdg:/proc# more inter*
>            CPU0       
>   0:    9016771          XT-PIC  timer
>   1:       2548          XT-PIC  keyboard
>   2:          0          XT-PIC  cascade
>   3:     100039          XT-PIC  NE2000
>  11:      19708          XT-PIC  aic7xxx
>  13:          0          XT-PIC  fpu
> NMI:          0
> ERR:          0
> 
> Shouldn't those XT-PICs be IO-APICs..?

Depends on the kernel revision - kernels before 2.2 don't support APICs.  
This is what my dual Pentium says (running 2.3.45):
           CPU0       CPU1
  0:   15208328   15105019    IO-APIC-edge  timer
  1:        445        396    IO-APIC-edge  keyboard
  2:          0          0          XT-PIC  cascade
  3:          3          8    IO-APIC-edge  serial
  4:          3          8    IO-APIC-edge  serial
  8:          2          4    IO-APIC-edge  rtc
 13:          1          0          XT-PIC  fpu
 14:     100268      95607    IO-APIC-edge  ide0
 15:          0          2    IO-APIC-edge  ide1
 17:    5969889    5966778   IO-APIC-level  eth0
 19:        516        464   IO-APIC-level  aic7xxx
NMI:   30313283   30313283
LOC:   30305847   30305846
ERR:          0

(Oops.  I guess Pentiums support IO-APIC as well)

IO-APICs would only show in /proc/interrupts if the hardware supported
them.  486s predate IO-APICs, and thus they won't be used.

-- 
----------------------------------------------------------------------
Phil Brutsche					pbrutsch@creighton.edu

"There are two things that are infinite; Human stupidity and the
universe. And I'm not sure about the universe." - Albert Einstein