Description wangchuanguo_lc 2023-05-16 15:03:15 UTC

Description of problem:
For Intel ethernet card(e.g. X710)
Set smp_affinity by writing /proc/irq/{$irq}/smp_affinity,
but effective_affinity does not equal to smp_affinity, and dmesg shows the warning:Affinity broken due to vector space exhaustion


How reproducible:
1、ethtool -K $eth_info ntuple on
2、cat /sys/class/net/enp33s0f0/device/numa_node  
--Assuming the output is :2
3、lscpu|grep node2
--Assuming the output is :NUMA node2 CPU(s):   12-17， 60-65
4、cat /proc/interrupts | grep $eth_info | awk -F ':' '{print $1}'
 --Assuming the output is :
 133
 134
 135
 136
 137
 138
 139
 140
5、echo 800000 > /proc/irq/137/smp_affinity
   cat /proc/irq/137/smp_affinity
   cat /proc/irq/137/effective_affinity

Actual results:
#cat /proc/irq/137/smp_affinity
00000000,00000000,00000000,00800000
#/proc/irq/137/effective_affinity
00000000,00000000,00000000,00800000

Expected results:
#cat /proc/irq/137/smp_affinity
00000000,00000000,00000000,00800000
#/proc/irq/137/effective_affinity
00000000,00000000,00000000,00000001