# uname -a 
Linux hustle 2.6.32-3-amd64 #1 SMP Wed Feb 24 18:07:42 UTC 2010 x86_64 GNU/Linux

# cat /proc/cpuinfo
...
processor       : 7
vendor_id       : GenuineIntel
cpu family      : 6
model           : 23
model name      : Intel(R) Xeon(R) CPU           E5410  @ 2.33GHz
stepping        : 6
cpu MHz         : 2327.577
cache size      : 6144 KB
physical id     : 1
siblings        : 4
core id         : 3
cpu cores       : 4
apicid          : 7
initial apicid  : 7
fpu             : yes
fpu_exception   : yes
cpuid level     : 10
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx lm constant_tsc arch_perfmon pebs bts rep_good aperfmperf pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm dca sse4_1 lahf_lm tpr_shadow vnmi flexpriority
bogomips        : 4655.33
clflush size    : 64
cache_alignment : 64
address sizes   : 38 bits physical, 48 bits virtual
power management:

# Header for /proc/interrupts for reference...
#          CPU0       CPU1       CPU2       CPU3       CPU4       CPU5       CPU6       CPU7

# grep '^ 64' /proc/interrupts && sleep 15 && grep '^ 64' /proc/interrupts 
 64:    8201417    8201529    8200276    8197421    8200250    8200304    8201232    8201092   PCI-MSI-edge      eth0
 64:    8201430    8201542    8200288    8197432    8200262    8200316    8201243    8201106   PCI-MSI-edge      eth0

# echo "f0" > /proc/irq/64/smp_affinity
# grep '^ 64' /proc/interrupts && sleep 15 && grep '^ 64' /proc/interrupts 
 64:    8201476    8201595    8200332    8197474    8200311    8200364    8201292    8201159   PCI-MSI-edge      eth0
 64:    8201476    8201595    8200332    8197474    8200327    8200381    8201308    8201175   PCI-MSI-edge      eth0

# Note that now interrupts are only ocurring on the last four processors