Re: [PATCH 2/4] hugetlbfs: move hugepagesz= parsing to arch independent code

[Mina Almasry <almasrymina@google.com>]

On Thu, Mar 19, 2020 at 12:04 AM Christophe Leroy
<christophe.leroy@c-s.fr> wrote:
>
>
>
> Le 18/03/2020 à 23:06, Mike Kravetz a écrit :
> > Now that architectures provide arch_hugetlb_valid_size(), parsing
> > of "hugepagesz=" can be done in architecture independent code.
> > Create a single routine to handle hugepagesz= parsing and remove
> > all arch specific routines.  We can also remove the interface
> > hugetlb_bad_size() as this is no longer used outside arch independent
> > code.
> >
> > This also provides consistent behavior of hugetlbfs command line
> > options.  The hugepagesz= option should only be specified once for
> > a specific size, but some architectures allow multiple instances.
> > This appears to be more of an oversight when code was added by some
> > architectures to set up ALL huge pages sizes.
> >
> > Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
> > ---
> >   arch/arm64/mm/hugetlbpage.c   | 15 ---------------
> >   arch/powerpc/mm/hugetlbpage.c | 15 ---------------
> >   arch/riscv/mm/hugetlbpage.c   | 16 ----------------
> >   arch/s390/mm/hugetlbpage.c    | 18 ------------------
> >   arch/sparc/mm/init_64.c       | 22 ----------------------
> >   arch/x86/mm/hugetlbpage.c     | 16 ----------------
> >   include/linux/hugetlb.h       |  1 -
> >   mm/hugetlb.c                  | 24 ++++++++++++++++++------
> >   8 files changed, 18 insertions(+), 109 deletions(-)
> >
>
> [snip]
>
> > diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> > index 2f99359b93af..cd4ec07080fb 100644
> > --- a/mm/hugetlb.c
> > +++ b/mm/hugetlb.c
> > @@ -3149,12 +3149,6 @@ static int __init hugetlb_init(void)
> >   }
> >   subsys_initcall(hugetlb_init);
> >
> > -/* Should be called on processing a hugepagesz=... option */
> > -void __init hugetlb_bad_size(void)
> > -{
> > -     parsed_valid_hugepagesz = false;
> > -}
> > -
> >   void __init hugetlb_add_hstate(unsigned int order)
> >   {
> >       struct hstate *h;
> > @@ -3224,6 +3218,24 @@ static int __init hugetlb_nrpages_setup(char *s)
> >   }
> >   __setup("hugepages=", hugetlb_nrpages_setup);
> >
> > +static int __init hugepagesz_setup(char *s)
> > +{
> > +     unsigned long long size;
> > +     char *saved_s = s;
> > +
> > +     size = memparse(s, &s);
>
> You don't use s after that, so you can pass NULL instead of &s and avoid
> the saved_s
>

+1

Acked-by: Mina Almasry <almasrymina@google.com>