On Fri, May 16, 2014 at 04:54:11PM +0100, Mark Salter wrote:
> On Fri, 2014-05-16 at 11:04 +0100, Catalin Marinas wrote:
> > On Thu, May 15, 2014 at 03:19:22PM +0100, Mark Salter wrote:
> > > diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c
> > > index 5e9aec3..9bed38f 100644
> > > --- a/arch/arm64/mm/hugetlbpage.c
> > > +++ b/arch/arm64/mm/hugetlbpage.c
> > > @@ -51,7 +51,11 @@ int pmd_huge(pmd_t pmd)
> > >
> > > int pud_huge(pud_t pud)
> > > {
> > > +#ifndef __PAGETABLE_PMD_FOLDED
> > > return !(pud_val(pud) & PUD_TABLE_BIT);
> > > +#else
> > > + return 0;
> > > +#endif
> > > }
> > >
> > > int pmd_huge_support(void)
> > > @@ -64,8 +68,10 @@ static __init int setup_hugepagesz(char *opt)
> > > unsigned long ps = memparse(opt, &opt);
> > > if (ps == PMD_SIZE) {
> > > hugetlb_add_hstate(PMD_SHIFT - PAGE_SHIFT);
> > > +#ifndef __PAGETABLE_PMD_FOLDED
> > > } else if (ps == PUD_SIZE) {
> > > hugetlb_add_hstate(PUD_SHIFT - PAGE_SHIFT);
> > > +#endif
> >
> > Since PMD_SIZE == PUD_SIZE when __PAGETABLE_PMD_FOLDED, do we need the
> > #ifndef here? Maybe the compiler is smart enough to remove it but it's
> > not on a critical path anyway, so I wouldn't bother.
>
> Yes, I think it would remove it. In any case, one less ifdef would be
> a good thing.
I merged this patch and dropped the last #ifndef.
I still have doubts about the kvm code calling put_page more than
necessary, especially since pud == pmd and the loop continues after
pud_huge() returns true, but your patch looks harmless.
Unless Steve has any objection, I'll push it to mainline. I also added
Cc: stable # v3.11+
Thanks.
--
Catalin
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