[RFC PATCH 13/13] um: nommu: plug nommu code into build system

[Hajime Tazaki]

On Sat, 26 Oct 2024 00:27:08 +0900,
Johannes Berg wrote:
> 
> On Fri, 2024-10-25 at 22:05 +0900, Hajime Tazaki wrote:
> > On Fri, 25 Oct 2024 18:33:06 +0900,
> > Johannes Berg wrote:
> > > 
> > > On Thu, 2024-10-24 at 21:09 +0900, Hajime Tazaki wrote:
> > > > 
> > > >  config MMU
> > > > -	bool
> > > > +	bool "MMU-based Paged Memory Management Support"
> > > >  	default y
> > > 
> > > "if !64bit" or something
> > 
> > not sure if I understand correctly but where do you suggest to add "if
> > !64bit" in this block ?
> 
> config MMU
> 	bool "..." if 64BIT
> 
> was what I was thinking, since you cannot allow !MMU on 32-bit.
> 
> As you wrote it, the user would get prompted on both 32 and 64 bit, and
> get an invalid configuration on 32-bit if they turn off MMU.

Ah, thanks.  Yes, the !MMU isn't available for now on 32-bit subarch
so, will fix it.

> > > > +config ARCH_FORCE_MAX_ORDER
> > > > +	int "Order of maximal physically contiguous allocations"
> > > > +	default "10" if MMU
> > > > +	default "16" if !
> > > 
> > > Should there even a be user prompt for it?
> > > Perhaps "if EXPERT" or something?
> > 
> > I think it's already user-editable 
> 
> It is now, but it didn't even exist before, so nobody would've been
> asked. I'm not sure it's _too_ useful to ask the users though? When
> would they know how to set it? (Perhaps also add some help text? I'm
> guessing it's related to the size of binaries or so?)

Ah, you're right.
I thought I only added !MMU part of this block (but it's not
correct)...

> > but your suggestion is to limit with 'if EXPERT' ?
> 
> Or maybe it should just not be user editable at all?

agreed to add if EXPERT.
I'll also add help text to that.

-- Hajime