Summary: Why on AS 8200 the CPU number begin from 8 instead of 0

From: Iwan R Tamimi <tamimii_at_m1.com.sg>
Date: Tue, 17 Apr 2001 09:21:15 +0800

Thanks for all the answers. It really helps me explain the things.


Regards,

Iwan


The Answers:

first

The 8200 is just the second half of the 8400 backplane. If you look at the
machine, you'll see that the CPU & Memory cards are in slots 8 and higher.

This is just a quirk of the 8200. I never found a way around it here
either.

John

second

Iwan...this is a feature of the Alphaserver 8200. We have such
a machine here that does the same thing.
The 8200 is a truncated version of the 8400 which has CPU's starting
from zero and CPU's on both front and back of the backplane.

Steve

third

The 8200 is 1/2 the 8400 with the number of bus slots. The code that maps
the bus knows the slot numbers for an 8200 represent the second 1/2 of this
bus, so the number begin with cpu 8.

jb




fourth

I think it also probably causes Monitor grief.

        The per-CPU process data is stored in a kernel data structure
        that is an array of "machine_slot" structures. I think these
        structures vaguely resemble the physical organization of the
        system components. My guess is that one (or more) of the
        following is true:

        o The CPUs really start at 8 with other components being
           earlier; Memory, I/O hoses, etc.

        o The numbering accurately reflects the physical slot
           number of the components.

        o The 8200, being a subset of the 8400, dropped off the
           lowered numbered slots instead of the higher numbered
           one. I believe the 8200 supports up to 6 CPUs while the
           8400 supports up to 14. The difference is 8, the starting
           point of CPUs on the 8200.

        The software solution should be relatively easy; separate
        the physical numbering of the machine_slots from a logical
        numbering that programs like collect and Monitor can use.
        I can't speak for the current authors of collect, but as
        author of Monitor, I don't have access to an 8200 for
        testing.

Alan

> -----Original Message-----
> From: Iwan R Tamimi
> Sent: Monday, April 16, 2001 2:24 PM
> To: 'TRU64 Mailing List'
> Subject: Why on AS 8200 the CPU number begin from 8 instead of 0
>
> Hi All,
>
> We have AS 8200 running Tru64 UNIX version 4.0F. Why when I ask to show
> the cpu (psrinfo) it always begins with 8, like the following:
>
> #> psrinfo
> 8 on-line since 03/30/2001 21:02:41
> 9 on-line since 03/30/2001 21:02:41
> 10 on-line since 03/30/2001 21:02:41
> 11 on-line since 03/30/2001 21:02:41
> 12 on-line since 03/30/2001 21:02:41
> 13 on-line since 03/30/2001 21:02:41
>
> I think this one causing the collect utility (unsupported performance
> monitor) don't give us the correct result.
> Actually I don't really care where the cpu begin from, I just need to run
> collect. Is there any workaroung?
>
> Thak you very much.
>
> Regards,
>
>
> Iwan R. Tamimi
>

Received on Tue Apr 17 2001 - 01:24:35 NZST

This archive was generated by hypermail 2.4.0 : Wed Nov 08 2023 - 11:53:42 NZDT