> Sent: Saturday, January 04, 2025 at 11:54 AM
> From: "Lee" <ler...@gmail.com>
> To: "Franco Martelli" <martelli...@gmail.com>
> Cc: debian-user@lists.debian.org
> Subject: Re: debian kernel compiler
>
> On Sat, Jan 4, 2025 at 7:52 AM Franco Martelli wrote:
> >
> > On 02/01/25 at 12:53, Istvan Toth wrote:
> > > amd 5700G cpu
> >
> > If you are new to kernel compiling maybe you don't know that you can
> > optimize the kernel for your specific CPU architecture, if you are using
> > the GCC compiler:
> >
> > first make a backup copy of the Makefile:
> > $ cd linux-source-6.1
> > $ cp arch/x86/Makefile arch/x86/Makefile.backup
> >
> > then edit "arch/x86/Makefile":
> > $ cd linux-source-6.1
> > $ vi arch/x86/Makefile
> >
> > at line 152 change:
> > cflags-$(CONFIG_MK8) += -march=k8
> > to
> > cflags-$(CONFIG_MK8) += -march=znver3
> > and below at line 159 change
> > rustflags-$(CONFIG_MK8) += -Ctarget-cpu=k8
> > to
> > rustflags-$(CONFIG_MK8) += -Ctarget-cpu=znver3
> >
> > save and exit vim. "znver3" is the GCC's switch for the µarch of your GPU.
>
> GPU or central processing unit?
>
> As long as you're not cross-compiling, how is march=znver3 better than
> march=native ?
>
> On my machine, 'man gcc' has the "znver1" and "znver2" strings, but no
> "znver3" so it seems like "march=native" would be more correct.. or
> at least less chances of an error.
> ... assuming there are no drawbacks to using "march=native".
>
> TIA,
> Lee
>
As someone that has compiled many a kernel on different platforms over 30
years......
gcc has a facility to interrogate the system it is on, it will tell you what is
available on the platform hardware and flag wise.
You should use that.
