Re: [PATCH] move __read_mostly to xen/cache.h

[Oleksii <oleksii.kurochko@xxxxxxxxx>]

On Tue, 2023-08-08 at 12:32 +0200, Jan Beulich wrote:
> On 08.08.2023 12:18, Andrew Cooper wrote:
> > On 08/08/2023 10:46 am, Jan Beulich wrote:
> > > There's no need for every arch to define its own identical copy.
> > > If down
> > > the road an arch needs to customize it, we can add #ifndef around
> > > the
> > > common #define.
> > > 
> > > To be on the safe side build-breakage-wise, change a couple of
> > > #include
> > > <asm/cache.h> to the xen/ equivalent.
> > > 
> > > Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
> > 
> > Could we find a better place to put this?
> > 
> > __read_mostly is just a section.  It's relationship to the cache is
> > only
> > microarchitectural, and is not the same kind of information as the
> > rest
> > of cache.h
> > 
> > __ro_after_init is only here because __read_mostly is here, but has
> > absolutely nothing to do with caches whatsoever.
> > 
> > If we're cleaning them up, they ought to live elsewhere.
> 
> I would be considering init.h (for having most other __section()
> uses,
> and for also needing __read_mostly), but that's not a great place to
> put these either. In fact I see less connection there than for
> cache.h.
> So the primary need is a good suggestion (I'm hesitant to suggest to
> introduce section.h just for this).
Andrew sent some suggestions here:
https://lore.kernel.org/xen-devel/3df1dad8-3476-458f-9022-160e0af57d39@xxxxxxxxxx/

Will that work for you?

>  In the absence of this, can we
> perhaps deal with this in a 2nd step, thus not blocking this patch
> and
> therefore not needing to then also clean up PPC-specific code?

~ Oleksii