Search code examples
linuxperformanceirq

linux irq affinity set cannot take effctive


when i set irq for my Ethernet cannot be effective. (irq from 99-119)

$ sudo cat /proc/irq/109/smp_affinity
00,00000400
$ sudo sh -c "echo 0 > /proc/irq/109/smp_affinity"
$ sudo cat /proc/irq/109/smp_affinity
00,00000400

i want to set all ethernet irq to bind with cpu0. but no lucky for me to set it. i am not sure what kind of problems i met. and i noticed affinity_hint has following value, and i cannot set it anyway.

$sudo cat /proc/irq/109/affinity_hint 
00,00000400
$ sudo sh -c "echo 0 > /proc/irq/109/affinity_hint"
sh: line 0: echo: write error: Input/output error

this system i have 2 cpus with 6 cores. and enable hyper thread. totally has 24 cpu cores.

Architecture:          x86_64
CPU op-mode(s):        32-bit, 64-bit
Byte Order:            Little Endian
CPU(s):                40
On-line CPU(s) list:   0-39
Thread(s) per core:    2
Core(s) per socket:    10
Socket(s):             2
NUMA node(s):          2
Vendor ID:             GenuineIntel
CPU family:            6
Model:                 62
Model name:            Intel(R) Xeon(R) CPU E5-2660 v2 @ 2.20GHz
Stepping:              4
CPU MHz:               1201.921
BogoMIPS:              4404.51
Virtualization:        VT-x
L1d cache:             32K
L1i cache:             32K
L2 cache:              256K
L3 cache:              25600K
NUMA node0 CPU(s):     0-9,20-29
NUMA node1 CPU(s):     10-19,30-39

please help advise how to resolve. thanks!


Solution

  • i have got the solution. i make a mistake here. it should be echo "1" for core 0, and echo "2" for core 1.