Re: [PATCH] parisc: fix PMD pages allocation by restoring pmd_alloc_one()

From: Mike Rapoport
Date: Sun Aug 16 2020 - 13:44:10 EST


On Sun, Aug 16, 2020 at 03:42:09PM +0100, Matthew Wilcox wrote:
> On Sun, Aug 16, 2020 at 05:24:03PM +0300, Mike Rapoport wrote:
> > From: Mike Rapoport <rppt@xxxxxxxxxxxxx>
> >
> > Commit 1355c31eeb7e ("asm-generic: pgalloc: provide generic pmd_alloc_one()
> > and pmd_free_one()") converted parisc to use generic version of
> > pmd_alloc_one() but it missed the fact that parisc uses order-1 pages for
> > PMD.
> >
> > Restore the original version of pmd_alloc_one() for parisc, just use
> > GFP_PGTABLE_KERNEL that implies __GFP_ZERO instead of GFP_KERNEL and
> > memset.
> >
> > Fixes: 1355c31eeb7e ("asm-generic: pgalloc: provide generic pmd_alloc_one() and pmd_free_one()")
> > Repoerted-by: Meelis Roos <mroos@xxxxxxxx>
>
> typo, "Reported-by"

Helge,

I presume this is going via parisc tree, do you mind fixing up
while applying?

> Reviewed-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
>
> > Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxx>
> > Tested-by: Meelis Roos <mroos@xxxxxxxx>
> > Link: https://lkml.kernel.org/r/9f2b5ebd-e4a4-0fa1-6cd3-4b9f6892d1ad@xxxxxxxx
> > ---
> >
> > Hi,
> >
> > I've trimmed the 'cc list relatively to the bug report and added parisc
> > maintainers.
> >
> > arch/parisc/include/asm/pgalloc.h | 6 ++++++
> > 1 file changed, 6 insertions(+)
> >
> > diff --git a/arch/parisc/include/asm/pgalloc.h b/arch/parisc/include/asm/pgalloc.h
> > index cc7ecc2ef55d..a6482b2ce0ea 100644
> > --- a/arch/parisc/include/asm/pgalloc.h
> > +++ b/arch/parisc/include/asm/pgalloc.h
> > @@ -10,6 +10,7 @@
> >
> > #include <asm/cache.h>
> >
> > +#define __HAVE_ARCH_PMD_ALLOC_ONE
> > #define __HAVE_ARCH_PMD_FREE
> > #define __HAVE_ARCH_PGD_FREE
> > #include <asm-generic/pgalloc.h>
> > @@ -67,6 +68,11 @@ static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)
> > (__u32)(__pa((unsigned long)pmd) >> PxD_VALUE_SHIFT)));
> > }
> >
> > +static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address)
> > +{
> > + return (pmd_t *)__get_free_pages(GFP_PGTABLE_KERNEL, PMD_ORDER);
> > +}
> > +
> > static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
> > {
> > if (pmd_flag(*pmd) & PxD_FLAG_ATTACHED) {
> > --
> > 2.26.2
> >

--
Sincerely yours,
Mike.