Re: [PATCH 03/13] mm: Add generic p?d_large() macros

[Liang, Kan]

On 2/18/2019 9:19 AM, Steven Price wrote:
> On 18/02/2019 11:31, Peter Zijlstra wrote:
> > On Fri, Feb 15, 2019 at 05:02:24PM +0000, Steven Price wrote:
> > > From: James Morse <james.morse@xxxxxxx>
> > >
> > > Exposing the pud/pgd levels of the page tables to walk_page_range() means
> > > we may come across the exotic large mappings that come with large areas
> > > of contiguous memory (such as the kernel's linear map).
> > >
> > > For architectures that don't provide p?d_large() macros, provided a
> > > does nothing default.
> >
> > Kan was going to fix that for all archs I think..

Yes, I'm still working on a generic function to retrieve page size.
The generic p?d_large() issue has been fixed. However, I found that the 
pgd_page() is not generic either. I'm still working on it.
I will update you on the other thread when all issues are fixed.



> The latest series I can find from Kan is still x86 specific. I'm happy
> to rebase onto something else if Kan has an implementation already
> (please point me in the right direction). Otherwise Kan is obviously
> free to base on these changes.

My implementation is similar as yours. I'm happy to re-base on your changes.

Could you please also add a generic p4d_large()?

Thanks,
Kan

> Steve
>
> > See:
> >
> >    http://lkml.kernel.org/r/20190204105409.GA17550@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
> >
> > > Signed-off-by: James Morse <james.morse@xxxxxxx>
> > > Signed-off-by: Steven Price <steven.price@xxxxxxx>
> > > ---
> > >   include/asm-generic/pgtable.h | 10 ++++++++++
> > >   1 file changed, 10 insertions(+)
> > >
> > > diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h
> > > index 05e61e6c843f..7630d663cd51 100644
> > > --- a/include/asm-generic/pgtable.h
> > > +++ b/include/asm-generic/pgtable.h
> > > @@ -1186,4 +1186,14 @@ static inline bool arch_has_pfn_modify_check(void)
> > >   #define mm_pmd_folded(mm)	__is_defined(__PAGETABLE_PMD_FOLDED)
> > >   #endif
> > >   
> > > +#ifndef pgd_large
> > > +#define pgd_large(x)	0
> > > +#endif
> > > +#ifndef pud_large
> > > +#define pud_large(x)	0
> > > +#endif
> > > +#ifndef pmd_large
> > > +#define pmd_large(x)	0
> > > +#endif
> > > +
> > >   #endif /* _ASM_GENERIC_PGTABLE_H */
> > > --
> > > 2.20.1
> >
> > _______________________________________________
> > linux-arm-kernel mailing list
> > linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel