On Sun, Jul 24, 2022 at 11:25:04AM +0200, Jan Engelhardt wrote:
On Saturday 2022-07-23 23:50, Adam Borowski wrote:
We are booting the i386 kernel on an x86 machine.
[..] And for quite some tasks, halved word size (thus ~2/3 memory usage) can overcome register starvation and win benchmarks.
So how many benchmarks does a 32-bit userspace with a 32-bit kernel win over 32-bit userspace with a 64-bit kernel?
Likely none or almost none. What we want is for people to run 64-bit kernel, there are no real issues with userland.
Valid uses to run 32-bit kernel: * ancient hardware (so much more prevalent than m68k we support!; non-hobbyists should upgrade to reduce power costs) * hardware to run that 100$k-1M ISA industrial control/medical imaging card (which, having ISA, is necessarily ancient too) * us devs testing the above
Only the last case will have a modern CPU, thus requiring an explicit override won't hurt less educated users -- while telling the latter to grab a 64-bit kernel if their hardware isn't ancient would have other benefits for them beside just vulnerabilities.
Meow!