Re: [PATCH 33 of 66] madvise(MADV_HUGEPAGE)

Andrea Arcangeli
2010-12-09T17:16:18Z

On Thu, Nov 18, 2010 at 03:19:35PM +0000, Mel Gorman wrote:
> On Wed, Nov 03, 2010 at 04:28:08PM +0100, Andrea Arcangeli wrote:
> > @@ -121,6 +122,11 @@ static inline int split_huge_page(struct
> > #define wait_split_huge_page(__anon_vma, __pmd) \
> > do { } while (0)
> > #define PageTransHuge(page) 0
> > +static inline int hugepage_madvise(unsigned long *vm_flags)
> > +{
> > + BUG_ON(0);
>
> What's BUG_ON(0) in aid of?

When CONFIG_TRANSPARENT_HUGEPAGE is disabled, nothing must call that
function (madvise must return -EINVAL like older kernels instead). But
I guess you meant I should convert the BUG_ON(0) to a BUG() instead? (done)

> I should have said it at patch 4 but don't forget that Michael Kerrisk
> should be made aware of MADV_HUGEPAGE so it makes it to a manual page
> at some point.

Ok, I'll forward patch 4.

Thanks,
Andrea