Re: irq balancing; kernel vs. userspace

Sean Neakums
2003-04-20T18:43:05Z

Arjan van de Ven <arjanv@redhat.com> writes:

> On Sun, 2003-04-20 at 15:23, 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.
>
> this looks like you haven't started the userspace daemon (yet)

I just cranked it up, and now I see:

$ cat /proc/interrupts
CPU0 CPU1
0: 9627420 12189635 IO-APIC-edge timer
1: 4165 4347 IO-APIC-edge i8042
2: 0 0 XT-PIC cascade
4: 282749 315988 IO-APIC-edge serial
8: 2 1 IO-APIC-edge rtc
9: 3 2 IO-APIC-level eth1
10: 19270 20109 IO-APIC-level via82cxxx, eth0
11: 34913 19457 IO-APIC-level aic7xxx
12: 8777 8835 IO-APIC-edge i8042
NMI: 0 0
LOC: 21817495 21817494
ERR: 0
MIS: 0

I was confused at first because I was thinking of IRQ balancing as
balancing IRQs *across* CPUs. This kind of balancing seems to be
about spreading IRQ *sources* across CPUs. I guess it's good for
caches and whatnot for IRQs to be consistently serviced by the same
CPU.

Anyway, it seems to be working. Thanks!

--
Sean Neakums - <sneakums@zork.net>