Binding NIC Interrupts to Cores

Purpose

Compared with using the kernel's irqbalance to schedule NIC interrupts across all cores, manually binding interrupts to cores can effectively improve the service network throughput.

Procedure

1. Disable irqbalance.

   Before binding cores to NICs, disable irqbalance.

   1. Stop the irqbalance service. The service will be invalid after the system restarts.

      1	systemctl stop irqbalance.service

   2. Disable the irqbalance service. This setting is permanently valid.

      1	systemctl disable irqbalance.service

   3. Check whether the irqbalance service is disabled.

      1	systemctl status irqbalance.service

2. Check the PCI device number of the NIC, assuming that the current NIC name is enp131s0.

   1	ethtool -i enp131s0

   

3. Check the NUMA node to which the PCIe NIC connects.

   1	lspci -vvvs <bus-info>

   

4. Check the core range corresponding to a NUMA node. For example, you can bind interrupts to cores 48 to 63.

   1

   lscpu

   

5. Bind interrupts to cores. The Hi1822 NIC has 16 queues. Bind the interrupts to the 16 cores of the NUMA node to which the NIC connect (for example, cores 48 to 63 corresponding to NUMA node 1).

   1	bash smartIrq.sh

   The script content is as follows:

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   #!/bin/bash irq_list=(`cat /proc/interrupts | grep enp131s0 | awk -F: '{print $1}'`) cpunum=48 # Change the value to the first core of the node. for irq in ${irq_list[@]} do echo $cpunum > /proc/irq/$irq/smp_affinity_list echo `cat /proc/irq/$irq/smp_affinity_list` (( cpunum+=1 )) done

6. Run the following command to check whether the core binding is successful.

   1	sh irqCheck.sh enp131s0

   

   The script content is as follows:

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   #!/bin/bash # NIC name intf=$1 log=irqSet-`date "+%Y%m%d-%H%M%S"`.log # Number of available CPUs cpuNum=$(cat /proc/cpuinfo |grep processor -c) # RX and TX interrupt lists irqListRx=$(cat /proc/interrupts | grep ${intf} | awk -F':' '{print $1}') irqListTx=$(cat /proc/interrupts | grep ${intf} | awk -F':' '{print $1}') # Bind the RX interrupt requests (IRQs). for irqRX in ${irqListRx[@]} do cat /proc/irq/${irqRX}/smp_affinity_list done # Bind the TX IRQs. for irqTX in ${irqListTx[@]} do cat /proc/irq/${irqTX}/smp_affinity_list done