Re: [PATCH v8 10/10] mm: Renumber FOLL_PIN and FOLL_GET down

[David Howells]

John Hubbard <jhubbard@xxxxxxxxxx> wrote:

> > Renumber FOLL_PIN and FOLL_GET down to bit 0 and 1 respectively so that
> > they are coincidentally the same as BIO_PAGE_PINNED and BIO_PAGE_REFFED and
> > also so that they can be stored in the bottom two bits of a page pointer
> > (something I'm looking at for zerocopy socket fragments).
> > (Note that BIO_PAGE_REFFED should probably be got rid of at some point,
> > hence why FOLL_PIN is at 0.)
> > Also renumber down the other FOLL_* flags to close the gaps.
> 
> Should we also get these sorted into internal-to-mm and public sets?
> Because Jason (+Cc) again was about to split them apart into
> mm/internal.h [1] and that might make that a little cleaner.

My plan was to push this patch by itself through akpm since it's only an
optimisation and not necessary to the rest of the patches here.

David