Скачать или смотреть How to Use Interrupts Effectively with DPDK: A Guide for Network Receive Threads

Learn how to enable effective interrupt handling in DPDK for network receive threads using the igb_uio and ixgbe drivers. Troubleshoot common issues in your setup with expert insights.
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How to Use Interrupts Effectively with DPDK: A Guide for Network Receive Threads

Handling network packets efficiently is crucial in high-performance environments. Many developers using the Data Plane Development Kit (DPDK) encounter challenges when working with interrupts for packet reception. This guide will guide you through the steps needed to enable interrupts in DPDK, specifically using the igb_uio and ixgbe drivers with an Intel 82599ES 10Gbps Network Interface Controller (NIC).

The Problem

You may find yourself in a situation where your network receive thread is not functioning as expected. You might want your thread to sleep on an epoll until packets arrive, but it only handles packets when the timeout occurs, leading to inefficient processing.

In some cases, while monitoring the /proc/interrupts, you may not see any interrupts arriving from the device. This can be frustrating, particularly when you believe this setup should be straightforward, using examples like l3fwd-power.

Possible Solution

After consulting with Dmitry Kozlyuk, we've identified critical steps you need to take to enable interrupts correctly. The ixgbe driver requires re-arming the interrupts before each call to rte_epoll_wait. Below, we'll break this down for clarity.

Step 1: Configuring Interrupts

Begin by ensuring you properly configure the port's interrupt settings:

[[See Video to Reveal this Text or Code Snippet]]

Step 2: Enable Receive Interrupts

You need to enable receive interrupts as follows. Pay close attention to the fact that this must occur before every call to rte_epoll_wait.

[[See Video to Reveal this Text or Code Snippet]]

Step 3: Use rte_epoll_wait Efficiently

Now, we'll use rte_epoll_wait within a loop. This is where the re-arming of the interrupt comes into play. Start by inserting this line before each wait call:

[[See Video to Reveal this Text or Code Snippet]]

Important Tips

Re-arm Requirement: Remember that not only the ixgbe driver but other drivers, such as vmxnet3, also require this re-arming step before each wait call.

Monitoring Interrupts: If you continue to encounter issues, it may be wise to further investigate the driver itself.

Conclusion

Using interrupts effectively in DPDK involves understanding specific requirements of your hardware and driver setup. By ensuring you re-arm interrupts before each call to rte_epoll_wait, you can allow your network receive thread to sleep until packets arrive, enhancing processing efficiency.

Feel free to reach out if you have additional questions or if you encounter further problems. We're here to support you on your DPDK journey!