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

Kernel micro-benchmarks also take a large hit with KPTI.

The NGINX web server is also affected from this Meltdown mitigation.

In some networking workloads, Kernel-based Page Table Isolation also will cause measurable performance overhead.

The situation isn't too different from when Linux x86_64 KPTI support was introduced, but at least there with newer CPUs having PCID there is less of a performance impact. If you are still using a Linux 32-bit PC on a regular basis and vulnerable to Meltdown, you may want to consider upgrading your hardware or booting with "nopti" if not worried about Meltdown mitigation once upgrading to the future Linux 4.19 kernel release or later.