From: Oleksandr Natalenko <oleksandr@redhat.com>
To: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: linux-kernel@vger.kernel.org, x86@kernel.org
Subject: Re: [PATCH] Kconfig: default to CC_OPTIMIZE_FOR_PERFORMANCE_O3 for gcc >= 10
Date: Fri, 8 May 2020 11:02:02 +0200 [thread overview]
Message-ID: <20200508090202.7s3kcqpvpxx32syu@butterfly.localdomain> (raw)
In-Reply-To: <20200507224530.2993316-1-Jason@zx2c4.com>
On Thu, May 07, 2020 at 04:45:30PM -0600, Jason A. Donenfeld wrote:
> GCC 10 appears to have changed -O2 in order to make compilation time
> faster when using -flto, seemingly at the expense of performance, in
> particular with regards to how the inliner works. Since -O3 these days
> shouldn't have the same set of bugs as 10 years ago, this commit
> defaults new kernel compiles to -O3 when using gcc >= 10.
>
> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
> ---
> init/Kconfig | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/init/Kconfig b/init/Kconfig
> index 9e22ee8fbd75..fab3f810a68d 100644
> --- a/init/Kconfig
> +++ b/init/Kconfig
> @@ -1245,7 +1245,8 @@ config BOOT_CONFIG
>
> choice
> prompt "Compiler optimization level"
> - default CC_OPTIMIZE_FOR_PERFORMANCE
> + default CC_OPTIMIZE_FOR_PERFORMANCE_O3 if GCC_VERSION >= 100000
> + default CC_OPTIMIZE_FOR_PERFORMANCE if (GCC_VERSION < 100000 || CC_IS_CLANG)
>
> config CC_OPTIMIZE_FOR_PERFORMANCE
> bool "Optimize for performance (-O2)"
> --
> 2.26.2
>
Should we untangle -O3 from depending on ARC first maybe?
--
Best regards,
Oleksandr Natalenko (post-factum)
Principal Software Maintenance Engineer
next prev parent reply other threads:[~2020-05-08 9:02 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-07 22:45 [PATCH] Kconfig: default to CC_OPTIMIZE_FOR_PERFORMANCE_O3 for gcc >= 10 Jason A. Donenfeld
2020-05-08 8:35 ` Peter Zijlstra
2020-05-08 9:02 ` Oleksandr Natalenko [this message]
2020-05-08 11:21 ` Jason A. Donenfeld
2020-05-08 11:33 ` Oleksandr Natalenko
2020-05-08 11:49 ` Arnd Bergmann
2020-05-08 12:07 ` Jason A. Donenfeld
2020-05-08 13:04 ` Arnd Bergmann
2020-05-08 15:06 ` Joe Perches
2020-05-08 15:09 ` Arnd Bergmann
2020-05-10 12:47 ` David Laight
2020-05-10 17:45 ` Joe Perches
2020-05-10 18:58 ` David Laight
2020-05-12 1:10 ` Masahiro Yamada
2020-05-11 21:57 ` [PATCH v2] " Jason A. Donenfeld
2020-05-12 0:04 ` Linus Torvalds
2020-05-12 0:09 ` Linus Torvalds
2020-05-12 0:43 ` Jason A. Donenfeld
2020-05-12 8:44 ` Richard Biener
2020-05-13 11:27 ` [PATCH] " Artem S. Tashkinov
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