Re: [PATCH 02/17] mm: stub out all of swapops.h for !CONFIG_MMU

From: Christoph Hellwig
Date: Fri Jun 14 2019 - 05:54:02 EST


On Tue, Jun 11, 2019 at 03:36:53PM +0100, Vladimir Murzin wrote:
> It looks like NOMMU ports tend to define those. For ARM they are:
>
> #define __swp_type(x) (0)
> #define __swp_offset(x) (0)
> #define __swp_entry(typ,off) ((swp_entry_t) { ((typ) | ((off) << 7)) })
> #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
> #define __swp_entry_to_pte(x) ((pte_t) { (x).val })
>
> Anyway, I have no strong opinion on which is better :)

It just seems a lot easier to stub out swapops.h rather than providing
stubs in each arch so that inlines which we are never going to use can
build. I can look into dropping this from the other nommu ports for
the next merge window, though.