32-Bit Linux Prepares For Performance Hit Due To KPTI For Meltdown Mitigation

First up are some I/O storage benchmarks given the performance impact found to disk transfer speeds when testing the original Linux x86_64 PTI.

In the case of the I/O benchmarks on this old ThinkPad laptop with Core 2 Duo, KPTI hadn't really hurt the performance but that's in large part because the storage on these old 10+ year old systems is already incredibly slow...

Similar to Linux x86_64, the HTTP performance in the Golang benchmark is hit hard by Kernel-based Page Table Isolation.

The build/compiler performance is impacted by a very slim amount with this Linux i686 testing... As mentioned above, the 5400 RPM HDD in this laptop is quite slow by today's standards and likely already a bottleneck even with KPTI disabled, unlike our Linux x86_64 benchmarks with speedy NVMe SSDs.

The Hackbench Linux kernel scheduler benchmark shows the huge performance hit from having Kernel-based Page Table Isolation enabled.