From: Ingo Molnar <mingo@kernel•org>
To: Stephen Rothwell <sfr@canb•auug.org.au>
Cc: "H. Peter Anvin" <hpa@zytor•com>,
Thomas Gleixner <tglx@linutronix•de>,
Ingo Molnar <mingo@redhat•com>,
Peter Zijlstra <peterz@infradead•org>,
Tor Vic <torvic9@mailbox•org>,
Linux Kernel Mailing List <linux-kernel@vger•kernel.org>,
Linux Next Mailing List <linux-next@vger•kernel.org>
Subject: [PATCH] x86/kbuild/64: Test for the availability of the -mtune=native compiler flag
Date: Mon, 24 Mar 2025 08:10:00 +0100 [thread overview]
Message-ID: <Z-EFSKxiqbGPT9CQ@gmail.com> (raw)
In-Reply-To: <20250324174141.7b3c4a70@canb.auug.org.au>
* Stephen Rothwell <sfr@canb•auug.org.au> wrote:
> Hi,
>
> On Sun, 23 Mar 2025 23:29:20 -0700 "H. Peter Anvin" <hpa@zytor•com> wrote:
> >
> > >$ x86_64-linux-gnu-gcc --version
> > >x86_64-linux-gnu-gcc (Debian 14.2.0-12) 14.2.0
> > >
> > >cross build - ppc hosted
> > >
> >
> > Cross compiling?
>
> Yes (see above :-))
Does the patch below fix the bug?
Thanks,
Ingo
=====================>
From: Ingo Molnar <mingo@kernel•org>
Date: Mon, 24 Mar 2025 08:05:19 +0100
Subject: [PATCH] x86/kbuild/64: Test for the availability of the -mtune=native compiler flag
Stephen reported this build failure when cross-compiling:
cc1: error: bad value 'native' for '-march=' switch
Test for the availability of the -march=native flag.
Reported-by: Stephen Rothwell <sfr@canb•auug.org.au>
Signed-off-by: Ingo Molnar <mingo@kernel•org>
Cc: Tor Vic <torvic9@mailbox•org>
Cc: Andy Lutomirski <luto@kernel•org>
Cc: Brian Gerst <brgerst@gmail•com>
Cc: Juergen Gross <jgross@suse•com>
Cc: H. Peter Anvin <hpa@zytor•com>
Cc: Kees Cook <keescook@chromium•org>
Cc: Josh Poimboeuf <jpoimboe@redhat•com>
Cc: Linus Torvalds <torvalds@linux-foundation•org>
Link: https://lore.kernel.org/r/20250324172723.49fb0416@canb.auug.org.au
---
arch/x86/Kconfig.cpu | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/arch/x86/Kconfig.cpu b/arch/x86/Kconfig.cpu
index 9d108a54c30a..87bede96e800 100644
--- a/arch/x86/Kconfig.cpu
+++ b/arch/x86/Kconfig.cpu
@@ -245,10 +245,14 @@ config MATOM
endchoice
+config CC_HAS_MARCH_NATIVE
+ # This flag might not be available in cross-compilers:
+ def_bool $(cc-option, -march=native)
+
config X86_NATIVE_CPU
bool "Build and optimize for local/native CPU"
depends on X86_64
- default n
+ depends on CC_HAS_MARCH_NATIVE
help
Optimize for the current CPU used to compile the kernel.
Use this option if you intend to build the kernel for your
next prev parent reply other threads:[~2025-03-24 7:10 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-03-24 6:27 linux-next: build failure after merge of the tip tree Stephen Rothwell
2025-03-24 6:29 ` H. Peter Anvin
2025-03-24 6:41 ` Stephen Rothwell
2025-03-24 7:10 ` Ingo Molnar [this message]
2025-03-24 8:06 ` [PATCH] x86/kbuild/64: Test for the availability of the -mtune=native compiler flag Stephen Rothwell
2025-03-24 8:26 ` Ingo Molnar
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=Z-EFSKxiqbGPT9CQ@gmail.com \
--to=mingo@kernel$(echo .)org \
--cc=hpa@zytor$(echo .)com \
--cc=linux-kernel@vger$(echo .)kernel.org \
--cc=linux-next@vger$(echo .)kernel.org \
--cc=mingo@redhat$(echo .)com \
--cc=peterz@infradead$(echo .)org \
--cc=sfr@canb$(echo .)auug.org.au \
--cc=tglx@linutronix$(echo .)de \
--cc=torvic9@mailbox$(echo .)org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox