Re: [PATCH 3/8] mm/memory_hotplug: add APIs for explicit online type control

[David Hildenbrand (Red Hat)]

On 1/23/26 20:12, Gregory Price wrote:
> On Fri, Jan 23, 2026 at 06:25:26PM +0000, Jonathan Cameron wrote:
> > On Thu, 22 Jan 2026 19:34:10 -0500
> > Gregory Price <gourry@xxxxxxxxxx> wrote:
> >
> > > Ah, this was lost on me.
> > >
> > >
> > > unclear to me how to restrict a function to specific drivers, but i can
> > > add add_and_online_memory_driver_managed() trivially so no big issue.
> >
> > Is EXPORT_SYMBOL_GPL_FOR_MODULE() enough?

It's also fine for me to just limit add_memory_driver_managed() to 
in-tree driver by using EXPORT_SYMBOL_FOR_MODULES.

But it might make nvidia unhappy :)

So maybe just adding a __add_memory_driver_managed() that gives us more 
control and using EXPORT_SYMBOL_FOR_MODULES is being a bit nicer for OOT 
modules.


(I guess __add_memory_driver_managed is a better name than 
add_and_online_memory_driver_managed, thinking about it)

> >
>
> Is the issue just that add_memory_driver_manage is `extern`?  

Heh, the "extern" is simply not necessary and can be dropped from all 
such functions. Not related to this. It's all about EXPORT_SYMBOL_GPL 
allowing anything that claims to be a GPL module to use this functionality.

> If so
> yeah, i can just do the EXPORT_*_GPL path.
>
> If you prefer FOR_MODULE, then yes I can do this.

I'd go for

	EXPORT_SYMBOL_FOR_MODULES(__add_memory_driver_managed, "dax")

(or would it be the kmem module?)

--
Cheers

David