Re: [PATCH 0/2] Kconfig: -O3 enablement

[Nick Desaulniers]

On Tue, Jun 21, 2022 at 6:35 AM Miko Larsson <mikoxyzzz@xxxxxxxxx> wrote:
>
> Hi,
>
> This very small series allows -O3 to be used for all architectures. The
> first patch marks -O3 as experimental, with the reasoning being that it
> might expose unwanted regressions to users, and the second patch
> actually allows -O3 by removing the "depend on ARC" string.

I think we should just remove -O3 support from KCONFIG.

If someone wants to mess around with "experimental features," there's
nothing stopping you from doing:

$ make KCFLAGS=-O3

>
> The reasoning behind this series is to open up -O3 so that bugs related
> to it (both compiler-related and kernel-related) can be discovered by
> eyeballs wanting to improve the "-O3 experience," as that might be
> beneficial to both compilers and the kernel. This has been attempted
> before [1], but unfortunately nothing ever came of it.
>
> [1] https://lore.kernel.org/lkml/20191211104619.114557-1-oleksandr@xxxxxxxxxx/
>
> Cc: linux-kbuild@xxxxxxxxxxxxxxx
> Cc: x86@xxxxxxxxxx
> Cc: Nathan Chancellor <nathan@xxxxxxxxxx>
> Cc: Vlastimil Babka <vbabka@xxxxxxx>
> Cc: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
> Cc: Sean Christopherson <seanjc@xxxxxxxxxx>
> Cc: "Gustavo A. R. Silva" <gustavoars@xxxxxxxxxx>
> Cc: Arnd Bergmann <arnd@xxxxxxxx>
> Cc: Chris Down <chris@xxxxxxxxxxxxxx>
> Cc: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
> Cc: John Ogness <john.ogness@xxxxxxxxxxxxx>
> Cc: Elliot Berman <quic_eberman@xxxxxxxxxxx>
> Cc: Oleksandr Natalenko <oleksandr@xxxxxxxxxx>
>
> Miko Larsson (2):
>   Kconfig: Mark -O3 as experimental
>   Kconfig: Allow -O3 for all architectures
>
>  init/Kconfig | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
>
> --
> 2.36.1
>


-- 
Thanks,
~Nick Desaulniers