VM Performance Showing Mixed Impact With Linux 4.15 KPTI Patches
Interestingly, PostgreSQL takes a smaller hit in performance with KPTI when running in a VM than when running on bare metal hardware. This may be due to the bare metal tests having higher I/O potential than the virtual disk used in this scenario.
Similar to the bare metal results, Redis also took a performance hit with this newer kernel code.
Some synthetic tests via Stress-NG are also indicating a measurable drop in performance.
Apache is also taking a hit of just under 10% on this VM when KPTI is being used.