DPDK added a RCU library with a novel method to reclaim resources. We have been running tests to understand the performance differences between the DPDK RCU and the user space RCU library. In our tests, we find that DPDK RCU can perform reclamation faster and perform significantly better when pre-emptive readers are involved. Other than the performance, DPDK RCU has several advantages such as not requiring a background thread for reclaiming resources and the ability to integrate with existing libraries without having to modify the application.
This talk will present various testing done on DPDK RCU and the user space RCU library and their results. It will go into the details of pre-emptive reader problem, which affects use cases beyond DPDK, and show that DPDK RCU library can reduce the reclamation time significantly.