[CentOS] Re: Re: irqbalance is dead, can not shutdown

Wed Apr 5 15:26:36 UTC 2006
Steven <asterisk at tescogroup.com>

cat /proc/interrupts is one indicator.
It will show the interrupt count on each processor for each device.
Run the command multiple times to see which column is incrementing the count.
Only one column will change at a time per device, that is the CPU that is handling it.

cat /proc/irq/209/smp_affinity will also show you the processor for each irq. (209 in this case)
echo 1 > /proc/irq/209/smp_affinity      will set CPU0 to process those interrupts.
echo 2 > /proc/irq/209/smp_affinity      will set CPU1 to process those interrupts.
echo 4 > /proc/irq/209/smp_affinity      will set CPU2 to process those interrupts.
echo 8 > /proc/irq/209/smp_affinity      will set CPU3 to process those interrupts.

These settings only stick if you have disables irqbalance.



"James Olin Oden" <james.oden at gmail.com> wrote in message 
news:ac921f990604050602h14555912h478ed2387ca5a43d at mail.gmail.com...
On 4/4/06, Steven <asterisk at tescogroup.com> wrote:
> I get better performance when I disable it.
> I put my PRI card interrupts on 1 CPU and my RAID controller, Eth, etc. on the other.
> This is a boost for my PRI cards. (digium cards for asterisk VOIP PBX)
> These cards produce 1000 interrupts per second.

Sow how do you do that?  Just curious...james
> irqbalance was reassigning the CPU for handling the interrupts on the PRI cards every few seconds.  During the switch, I would 
> drop
> a few interrupts.
How does one note when the irq's are  being changed for particular devices?