Linux网卡软中断绑定CPU核心

在极限并发时，系统自动分配CPU负载均衡，并不能最大效率，这个时候就要使用网卡软中断绑定CPU，高端网卡支持队列可以绑定队列到CPU核心，来优化Linux网络吞吐的效率。

本例使用intel D525 CPU

查看irq资源

[root@LeeRouter ~]# cat /proc/interrupts
           CPU0       CPU1       CPU2       CPU3       
  0:        138          3          4          7   IO-APIC-edge      timer
  1:          1          0          0          1   IO-APIC-edge      i8042
  8:          0          1          0          0   IO-APIC-edge      rtc0
  9:          1          0          1          1   IO-APIC-fasteoi   acpi
 12:          0          1          2          1   IO-APIC-edge      i8042
 14:          0          0          0          0   IO-APIC-edge      ata_piix
 15:          0          0          0          0   IO-APIC-edge      ata_piix
 16:          0          0          0          0   IO-APIC-fasteoi   uhci_hcd:usb3
 18:        869        860        871        877   IO-APIC-fasteoi   ehci_hcd:usb1, uhci_hcd:usb7, ata_piix
 19:          0          0          0          0   IO-APIC-fasteoi   uhci_hcd:usb6
 21:          8          9          9          8   IO-APIC-fasteoi   uhci_hcd:usb4
 23:          0          0          0          0   IO-APIC-fasteoi   ehci_hcd:usb2, uhci_hcd:usb5
 24:          0          0          0          0   PCI-MSI-edge      pciehp
 25:          0          0          0          0   PCI-MSI-edge      pciehp
 26:          0          0          0          0   PCI-MSI-edge      pciehp
 27:          0          0          0          0   PCI-MSI-edge      pciehp
 28:          0          0          0          0   PCI-MSI-edge      pciehp
 29:          0          0          0          0   PCI-MSI-edge      pciehp
 30:          2          3          2          2   PCI-MSI-edge      i915
 31:     254814     360483     272099     272226   PCI-MSI-edge      eth0
 32:        518        504        740        524   PCI-MSI-edge      eth1
 33:     369892     269639     243485     243150   PCI-MSI-edge      eth2
NMI:         35         43         32         35   Non-maskable interrupts
LOC:      67123      43720      59099      90278   Local timer interrupts
SPU:          0          0          0          0   Spurious interrupts
PMI:         35         43         32         35   Performance monitoring interrupts
IWI:          0          0          0          0   IRQ work interrupts
RES:        613        555        402        473   Rescheduling interrupts
CAL:        848       1010        137        157   Function call interrupts
TLB:        451        414       1140       1105   TLB shootdowns
TRM:          0          0          0          0   Thermal event interrupts
THR:          0          0          0          0   Threshold APIC interrupts
MCE:          0          0          0          0   Machine check exceptions
MCP:         16         16         16         16   Machine check polls

可以看到eth0 eth1 eth2是平均负载在4个CPU核心上

echo 0 > /proc/irq/31/smp_affinity_list
echo 1 > /proc/irq/32/smp_affinity_list
echo 2 > /proc/irq/33/smp_affinity_list

分配网卡软中断到不同的CPU核心。

重启会失效，所以将命令写入 /etc/rc.local

vi /etc/rc.local
echo 0 > /proc/irq/31/smp_affinity_list
echo 1 > /proc/irq/32/smp_affinity_list
echo 2 > /proc/irq/33/smp_affinity_list