Re: Hardware Interrupt Balancing

[James Lamanna]

--James

On Mar 25, 2010, at 3:36, Alejandro Riveira FernÃndez <ariveira@xxxxxxxx 
m> wrote:

> El Wed, 24 Mar 2010 18:11:36 -0700
> James Lamanna <jlamanna@xxxxxxxxx> escribiÃ:
>
> > Hi,
> > I have a Dual Xeon (single core each w/HT) machine and I noticed the
> > other day that interrupts are not
> > being balanced across the 2 processors:
> >
> >          CPU0       CPU1       CPU2       CPU3
> >  0:        306          0          0 3254413993    IO-APIC-edge   
> > timer
> >  1:          0          0          0      13468    IO-APIC-edge   
> > i8042
> >  8:          0          0          0          3    IO-APIC-edge  rtc
> >  9:          0          0          0          0   IO-APIC-level  acpi
> > 12:          0          0          0          4    IO-APIC-edge   
> > i8042
> > 169:          0          0          0          0   IO-APIC-level   
> > uhci_hcd:usb2
> > 177:          0          0          0   16743166   IO-APIC-level   
> > ata_piix
> > 185:          0          0          0          1   IO-APIC-level   
> > ehci_hcd:usb1
> > 193:          0          0          0          0   IO-APIC-level   
> > uhci_hcd:usb3
> > 201:          0          0          0 1867922172   IO-APIC-level   
> > eth0
> > 209:          0          0          0 3254690559   IO-APIC-level   
> > wct4xxp
> > NMI:          1          0          0          0
> > LOC: 3255261535 3255261540 3255261549 3255220504
> > ERR:          0
> > MIS:          0
> >
> > However the cpu_affinity of say, wct4xxp is:
> > # cat /proc/irq/209/smp_affinity
> > 0000000f
>
> Maybe you just need to run irqbalance http://www.irqbalance.org/
>  sudo aptitude install irqbalance  in Debian system

I do not want to use irq balance because everytime irqbalance moves  
the CPU of my PRI card, there is a hiccup in voice calls.
I manually moved the interrupts for the wct4xxp to CPU0 using  
smp_affinity = 1.

However today I got a lot of soft lockups on CPU0 due to asterisk in  
udp_sendmsg() - unsure if moving the interrupt caused this...could it?

Thanks.

-- James
>
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