Re: [PATCH v3] erofs: cap LZMA stream pool size

[Gao Xiang <xiang@kernel.org>]

Hi Guenter,

On Wed, Aug 12, 2026 at 07:25:50AM -0700, Guenter Roeck wrote:

...

> > > 
> > > Thank you, that seems to work (despite still seeing the warning on m68k,
> > > as NR_CPUS does not exist).
> > > 
> > 
> > ...
> > 
> > > 
> > >        $ make ARCH=m68k allmodconfig
> > >       fs/erofs/Kconfig:137:warning: range is invalid
> > > 
> > >   Warning...
> > > 
> > 
> > Yes, other arches shouldn't have the warning because I think other
> > arches (including microblaze) defines NR_CPUS in Kconfig, except m68k.
> > 
> 
> That is not entirely true. openrisc only has it if SMP=y. But it still
> does not generate the warning for some reason.
> 

I looked into the documentation a bit
(https://docs.kernel.org/kbuild/kconfig-language.html), especially the
following parts:

 - type definition: “bool”/”tristate”/”string”/”hex”/”int” ...
 - input prompt: “prompt” <prompt> [“if” <expr>] ...
     and "If a prompt is not present, the config option is
          a non-visible symbol, ..."

 - dependencies: “depends on” <expr> [“if” <expr>] ...
 - Menu dependencies ..

and I think that is true, taking openrisc for example:

config NR_CPUS
        int "Maximum number of CPUs (2-32)"
        range 2 32
        depends on SMP
        default "2"

which can be transformed into

config NR_CPUS
        int
	prompt "Maximum number of CPUs (2-32)"
	range 2 32
	depends on SMP
        default "2"

which can be then transformed into

config NR_CPUS
        int
	prompt "Maximum number of CPUs (2-32)" if SMP
	range 2 32 if SMP
        default "2" if SMP

so if `SMP=n`, it's equivalent to

config NR_CPUS
        int

so NR_CPUS symbol is still there I think (and its value is 0.)

Thanks,
Gao Xiang