Re: [PATCH hmm v2 1/5] mm/hmm: make CONFIG_DEVICE_PRIVATE into a select

[Jason Gunthorpe]

On Sat, May 09, 2020 at 05:16:12PM -0700, Andrew Morton wrote:
> On Fri,  1 May 2020 15:20:44 -0300 Jason Gunthorpe <jgg@xxxxxxxx> wrote:
> 
> > From: Jason Gunthorpe <jgg@xxxxxxxxxxxx>
> > 
> > There is no reason for a user to select this or not directly - it should
> > be selected by drivers that are going to use the feature, similar to how
> > CONFIG_HMM_MIRROR works.
> > 
> > Currently all drivers provide a feature kconfig that will disable use of
> > DEVICE_PRIVATE in that driver, allowing users to avoid enabling this if
> > they don't want the overhead.
> > 
> 
> I'm not too sure what's going on here, but i386 allmodconfig broke.
> 
> kernel/resource.c: In function '__request_free_mem_region':
> kernel/resource.c:1653:28: error: 'PA_SECTION_SHIFT' undeclared (first use in this function); did you mean 'SECTIONS_PGSHIFT'?
>   size = ALIGN(size, 1UL << PA_SECTION_SHIFT);
> 
> because in current mainline, allmodconfig produces
> CONFIG_DEVICE_PRIVATE=n but in current linux-next, allmodconfig
> produces CONFIG_DEVICE_PRIVATE=y.  But CONFIG_SPARSEMEM=n so the build
> breaks.

I think Arnd identified this, let us just revet the patch that caused
it.

> Bisection fingers this commit, but reverting it doesn't seem to fix
> things.  Could you take a look please?

There is a latter patch adding a 'select DEVICE_PRIVATE' so reverting
this needs to swap that to 'depends on'.

I've done both and updated git

Regards,
Jason