Performance Differences Between CentOS 7.9 and Rocky Linux 8.9 - A Root Cause Analysis and Recommendations
Introduction
A mutex (meaning mutual exclusion) prevents multiple threads from accessing the same resource simultaneously. When CIQ was running a futex test (a form of testing that checks the Linux kernel futex system call API), we observed mutex slowdown when running the futex testing on Rocky Linux 8.9 compared with CentOS 7.9.
We investigated this performance discrepancy further and this article will reveal why there was a performance differential between the two operating systems.
Resolution
The performance differences between both operating systems were due to the BIOS settings on the HPE Blade machines that were used for testing. The CPU governor settings were set to balanced power saving mode.
Upon configuring the CPU governor to static high performance mode in the BIOS, we saw a dramatic increase in performance for Rocky Linux 8.9.
Running the futex tests again on both Rocky Linux 8.9 and CentOS 7.9 produced the performance results as expected.
We also advise setting the tuned-adm profile to hpc-compute to ensure maximum performance from Rocky Linux.
Conclusion
When comparing performance between a Rocky Linux X.X version and another operating system, CIQ advises checking that the BIOS settings have the CPU governor configured for maximum performance.
In addition, we advise setting the tuned-adm profile to hpc-compute to ensure maximum performance from Rocky Linux.