Re: [PATCH 5/7] rust: file: add `Kuid` wrapper

From: Miguel Ojeda
Date: Fri Dec 08 2023 - 12:38:06 EST


On Fri, Dec 8, 2023 at 6:09 PM Nick Desaulniers <ndesaulniers@xxxxxxxxxx> wrote:
>
> On paper, nothing comes to mind. No promises though.

Thanks Nick -- that is useful nevertheless.

> From a build system perspective, I'd rather just point users towards
> LTO if they have this concern. We support full and thin lto. This
> proposal would add a third variant for just rust drivers. Each
> variation on LTO has a maintenance cost and each have had their own
> distinct fun bugs in the past. Not sure an additional variant is
> worth the maintenance cost, even if it's technically feasible.

I was thinking it would be something always done for Rust object
files: under a normal "no LTO" build, the Rust object files would
always get the cross-language inlining done and therefore no extra
dimension in the matrix. Would that help?

I think it is worth at least considering, given there is also a
non-trivial amount of performance to gain if we always do it, e.g.
Andreas wanted it for non-LTO kernel for this reason.

Cheers,
Miguel