Re: Building kernels with FPU support?

On Wed, 23 Oct 2024 10:38:12 -0400
gnn <gnn@freebsd.org> wrote:

> Howdy,
> 
> I am wondering if anyone has tried, lately, to see what effect
> building with FPU support has on overall system performance.  I've
> been working with a kernel module that needs this (for reasons I'll
> not go into now) and it occurred to me that the perceived performance
> overhead that caused us to only do fixed point in the kernel may no
> longer be significant.  I note that Linux has an option to build
> their kernel with FPU support.
> 
> And yes, I know that we have the ability to selectively deal with the
> FPU, from the calls outlined in Section 9 for fpu, but I'm asking the
> more general question of "does it matter?" and "if so, how much?"

Would be great to have it for e.g. having portions of SQLite in kernel,
e.g. it's R*Tree module for fast 5-dimensions lookup (like for firewall
rules) uses floats.

-- 
WBR, @nuclight