Re: irq balancing; kernel vs. userspace

[Zwane Mwaikambo]

On Sun, 20 Apr 2003, Sean Neakums wrote:

> I thought I'd play with the userspace IRQ-balancer, but booting with
> noirqbalance seems not to not balance.  Possibly I misunderstand how
> this all fits together.
> 
> $ uname -a
> Linux peng-33 2.5.68 #1 SMP Sun Apr 20 13:06:57 IST 2003 i686 unknown unknown GNU/Linux
> $ cat /proc/cmdline
> auto BOOT_IMAGE=default ro root=801 noirqbalance
> $ cat /proc/interrupts 
>            CPU0       CPU1       
>   0:     853487     854900    IO-APIC-edge  timer
>   1:          9          4    IO-APIC-edge  i8042
>   2:          0          0          XT-PIC  cascade
>   4:      15548      15161    IO-APIC-edge  serial
>   8:          2          1    IO-APIC-edge  rtc
>   9:          3          2   IO-APIC-level  eth1
>  10:       1784       1805   IO-APIC-level  via82cxxx, eth0
>  11:      10939      10860   IO-APIC-level  aic7xxx
>  12:         39         21    IO-APIC-edge  i8042
> NMI:          0          0 
> LOC:    1708150    1708149 
> ERR:          0
> MIS:          0

Local APICs before P4 by default arbitrated for interrupt handling, via a 
round robin type scheme, this doesn't seem to be the case with P4 since the 
Arbitration ID register is also gone now.

	Zwane
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