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From:   Mina Almasry <almasrymina@google.com>
Date:   Mon, 23 Mar 2020 16:56:43 -0700
Message-ID: <CAHS8izOeYeVi-W7z-DKw3Uv0rAqwuD1__uTr-oF6Lx=V9ekm3g@mail.gmail.com>
Subject: Re: [PATCH 2/4] hugetlbfs: move hugepagesz= parsing to arch
 independent code
To:     Christophe Leroy <christophe.leroy@c-s.fr>
Cc:     Mike Kravetz <mike.kravetz@oracle.com>,
        Linux-MM <linux-mm@kvack.org>,
        open list <linux-kernel@vger.kernel.org>,
        linux-arm-kernel@lists.infradead.org,
        linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org,
        linux-s390@vger.kernel.org, sparclinux@vger.kernel.org,
        linux-doc@vger.kernel.org, Albert Ou <aou@eecs.berkeley.edu>,
        Andrew Morton <akpm@linux-foundation.org>,
        Vasily Gorbik <gor@linux.ibm.com>,
        Jonathan Corbet <corbet@lwn.net>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Dave Hansen <dave.hansen@linux.intel.com>,
        Heiko Carstens <heiko.carstens@de.ibm.com>,
        Christian Borntraeger <borntraeger@de.ibm.com>,
        Ingo Molnar <mingo@redhat.com>,
        Palmer Dabbelt <palmer@dabbelt.com>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        Paul Mackerras <paulus@samba.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Longpeng <longpeng2@huawei.com>, Will Deacon <will@kernel.org>,
        "David S . Miller" <davem@davemloft.net>
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On Thu, Mar 19, 2020 at 12:04 AM Christophe Leroy
<christophe.leroy@c-s.fr> wrote:
>
>
>
> Le 18/03/2020 =C3=A0 23:06, Mike Kravetz a =C3=A9crit :
> > Now that architectures provide arch_hugetlb_valid_size(), parsing
> > of "hugepagesz=3D" can be done in architecture independent code.
> > Create a single routine to handle hugepagesz=3D 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=3D 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=3D... option */
> > -void __init hugetlb_bad_size(void)
> > -{
> > -     parsed_valid_hugepagesz =3D 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=3D", hugetlb_nrpages_setup);
> >
> > +static int __init hugepagesz_setup(char *s)
> > +{
> > +     unsigned long long size;
> > +     char *saved_s =3D s;
> > +
> > +     size =3D 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>