[CentOS] performance and interrupts

Fri Sep 24 13:43:41 UTC 2010
JohnS <jses27 at gmail.com>

On Fri, 2010-09-24 at 08:57 -0400, Mag Gam wrote:
> I am playing around with irqbalance to tune my 8 core system so I came
> across this page,
> http://kb.fusionio.com/KB/a65/irqbalance-avoid-overloading-cpu-0-with-interrupt-requests.aspx
> 
> Now, lets say I disable irqbalance which will stop my autobalance and
> I pin all of my interrupts to core 0 and pin eth0 and eth1 to core 1.
> My application is network and CPU hungry. I am planning to dedicate
> cpu 3 to 8 for the application using taskset.  Is there any draw back
> to this?
---
NO but be aware of what your doing as to not starve out Kernel Threads.
Whats the kernel? It want hurt to give them priority either. Gbit and
higher nics I would give them there own cpu.  It may take quit a while
to come up with the optimal configuration though.
Example:
cpu0 app priority 60 - 99 no ionice is app dependent 
cpu1 app
cpu2 eth0
cpu3 eth1
cpu4 fusionio
cpu5 fusionio
cpu6 kthreads 
cpu7 kthreads, misc

John