Re: ACPI oddity

From: Bill Davidsen
Date: Tue Jul 26 2005 - 08:20:00 EST

Brown, Len wrote:
On a HT system, why does ACPI recognize CPU0 and CPU1, refer to them as such in dmesg

This is the Linux CPU number. ie the namespace where 0
is the boot processor and the others are numbered in
the order that they were started.

and then call them CPU1 and CPU2 in /proc/acpi/processor?

These are arbitrary device identifiers written
by the BIOS developer and foolishly advertised
to the user by Linux. The BIOS writer could have
also called them ABC9 and XYZ4 and it would be
equally valid.

Which explains why they are CPU1 and CPU2 on ASUS and CPU0 and CPU1 on another system. I was hoping I had found something for the person who was having problems with the P4P800 mobo, but looks like it's not here.

We're planning to get rid of all the ACPI stuff
in /proc and move to sysfs. At that time we'll
use device identifies that are deterministic,
like cpu%d that /sys/devices/system uses today.

Whatever, it's cosmetic and there seem to be more important problems with APIC than /proc vs. /sys.

Thanks for the clarification.

-bill davidsen (davidsen@xxxxxxx)
"The secret to procrastination is to put things off until the
last possible moment - but no longer" -me
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