linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
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


  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 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

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200508090202.7s3kcqpvpxx32syu@butterfly.localdomain \
    --to=oleksandr@redhat.com \
    --cc=Jason@zx2c4.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=x86@kernel.org \
    --subject='Re: [PATCH] Kconfig: default to CC_OPTIMIZE_FOR_PERFORMANCE_O3 for gcc >= 10' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).