Hi Matt,
You said:
> After pouring over what I could find of the mp spec for intel('cause
> thats what I have to work with) I discovered that both FreeBSD and
> Linux use the "Virtual-wire" mode for the APIC under smp. This means
> that only the BSP handles irq's! Seems like that is done to keep the
> code down, but I am not an OS engineer. I could find little about the
> "symmetric-mode" that is also available and only a description that
> states that 'each processor can handle ANY interrupt."
Your reading of MP specs is adequate but reading of Linux kernel sources
(not sure about FreeBSD but they usually lag several years behind Linux
wrt modern technologies) is not. Linux does enter symmetric io mode and
any processor can handle irqs:
# uname -a ; cat /proc/interrupts
Linux elisha 2.3.45 #1 SMP Mon Feb 14 08:57:20 GMT 2000 i686 unknown
CPU0 CPU1
0: 3645584 3657606 IO-APIC-edge timer
1: 0 2 IO-APIC-edge keyboard
2: 0 0 XT-PIC cascade
8: 0 1 IO-APIC-edge rtc
13: 1 0 XT-PIC fpu
14: 2 3 IO-APIC-edge ide0
22: 17 13 IO-APIC-level sym53c8xx
23: 8330283 8320755 IO-APIC-level sym53c8xx
30: 53901 53928 IO-APIC-level TLAN
NMI: 7303042 7303042
LOC: 7302068 7302305
ERR: 0
Perhaps you were talking about some old versions of Linux (e.g. 2.0.x)
which couldn't do that? Even kernels as old as 2.2.x work just
fine in this area.
Regards,
------
Tigran A. Aivazian | http://www.sco.com
Escalations Research Group | tel: +44-(0)1923-813796
Santa Cruz Operation Ltd | http://www.ocston.org/~tigran
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.tux.org/lkml/
This archive was generated by hypermail 2b29 : Tue Feb 15 2000 - 21:00:29 EST