Re: [PATCH v4 00/40] lib/find: add atomic find_bit() primitives

From: Linus Torvalds
Date: Thu Jun 20 2024 - 16:32:33 EST


On Thu, 20 Jun 2024 at 13:20, Yury Norov <yury.norov@xxxxxxxxx> wrote:
>
> FORCE_NR_CPUS helped to generate a better code for me back then. I'll
> check again against the current kernel.

Of _course_ it generates better code.

But when "better code" is a source of bugs, and isn't actually useful
in general, it's not better, is it.

> The 5d272dd1b343 is wrong. Limiting FORCE_NR_CPUS to UP case makes no
> sense because in UP case nr_cpu_ids is already a compile-time macro:

Yury, I'm very aware. That was obviously intentional. the whole point
of the commit is to just disable the the whole thing as useless and
problematic.

I could have just ripped it out entirely. I ended up doing a one-liner instead.

Linus