RE: [PATCH 2/2] x86, Makefile: Add new generic x86-64 settings v2/v3/v4

[David Laight]

From: Christoph Hellwig
> Sent: 18 August 2021 08:15
> 
> On Tue, Aug 17, 2021 at 04:24:48PM +0200, torvic9@xxxxxxxxxxx wrote:
> > +	  Generic x86-64 CPU.
> > +	  Run equally well on all x86-64 CPUs with min support of x86-64-v2.
> 
> > +	help
> > +	  Generic x86-64-v3 CPU with v3 instructions.
> > +	  Run equally well on all x86-64 CPUs with min support of x86-64-v3.
> > +
> 
> > +	help
> > +	  Generic x86-64 CPU with v4 instructions.
> > +	  Run equally well on all x86-64 CPUs with min support of x86-64-v4.
> 
> How the f&%$% is a user supposed to know what these garbage descriptions
> are supposed to mean?

My thoughts.
I then looked up the link.
Most of the extra instructions are the AVX related ones.
They better not get enabled for a kernel build at all.

I wish I knew whether 'no-avx' actually implied 'no-avx2' and
all later avx options?
Or do kernel builds have to spot each new option and disable
in in turn?

	David

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