In this article, the author discusses their experience with profiling ZFS on Arch Linux. They initially encountered a problem where the z_rd_int processes were consuming a significant amount of CPU time while playing a video game. Despite having a non-compressed ZFS dataset and low disk IO wait times, the CPU usage was unexpectedly high. To investigate the issue, the author enabled debug symbols for ZFS using DKMS package and performed profiling using perf. The profiling revealed that the high CPU usage was due to encryption processes related to the AES-CCM algorithm. The author plans to migrate their dataset to AES-GCM encryption in the future to improve performance.
https://www.binwang.me/2023-12-14-ZFS-Profiling-on-Arch-Linux.html