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

[John Hubbard]

On 1/23/23 19:08, John Hubbard wrote:
> On 1/23/23 09:30, David Howells 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.

I see that I omitted both Jason's Cc and the reference, so I'll resend.
Sorry for the extra noise.

[1] https://lore.kernel.org/all/fcdb3294-3740-a0e0-b115-12842eb0696d@xxxxxxxxxx/

> Also, I don't think that there is any large readability difference
> either way between 0x and <<1, so whatever you and Christophe settle on
> there seems fine.
>
> So either way with those points,
>
> Reviewed-by: John Hubbard <jhubbard@xxxxxxxxxx>
>
> thanks,

thanks,
--
John Hubbard
NVIDIA