I am trying to post the following question and getting this post does not meet our quality standards. Can someone please tell me why? Can I suggest more constructive denials?
I have a machine with 32 cpus (NUMA) running CentOS 6.4. I would like to dedicate cpus 0-27 to my application, and leave the other 4 for everything else, including irq handling.
Is it enough to set isolcpus=0-27
in grub.conf, or do I need to also configure irqbalance to mask IRQBALANCE_BANNED_CPUS=0fffffff
?
I thought I could verify this with cat /proc/irq/*/smp_affinity
after setting that irqbalance variable and restarting, but I see affinities like this:
0000ff00
0000ff00
ffffffff
0000ff00
0000ff00
0000ff00
0000ff00
0000ff00
0000ff00
00ff0000
00ff0000
00ff0000
00ff0000
ffffffff
00ff0000
00ff0000
00ff0000
00ff0000
ff000000
ff000000
ff000000
or, if I start irqbalance in the foreground with --debug, I see this:
NUMA NODE NUMBER: 0
LOCAL CPU MASK: 000000ff
NUMA NODE NUMBER: 1
LOCAL CPU MASK: 0000ff00
NUMA NODE NUMBER: 2
LOCAL CPU MASK: 00ff0000
NUMA NODE NUMBER: 3
LOCAL CPU MASK: ff000000
both of which make me think irqbalance doesn't work properly with NUMA, etc. Any ideas?