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
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?