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From:   Pasha Tatashin <pasha.tatashin@soleen.com>
Date:   Wed, 20 Apr 2022 12:44:07 -0400
Message-ID: <CA+CK2bCF=7mADB=rxyHtVEd3oCZ4mxtKf=28L49uQr5oxUwYZQ@mail.gmail.com>
Subject: Re: [PATCH -next v4 1/4] mm: page_table_check: move
 pxx_user_accessible_page into x86
To:     Tong Tiangen <tongtiangen@huawei.com>
Cc:     Anshuman Khandual <anshuman.khandual@arm.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        Dave Hansen <dave.hansen@linux.intel.com>,
        "maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)" <x86@kernel.org>,
        "H. Peter Anvin" <hpa@zytor.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Will Deacon <will@kernel.org>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        Palmer Dabbelt <palmer@dabbelt.com>,
        Albert Ou <aou@eecs.berkeley.edu>,
        LKML <linux-kernel@vger.kernel.org>,
        linux-mm <linux-mm@kvack.org>,
        Linux ARM <linux-arm-kernel@lists.infradead.org>,
        linux-riscv@lists.infradead.org,
        Kefeng Wang <wangkefeng.wang@huawei.com>,
        Guohanjun <guohanjun@huawei.com>
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On Wed, Apr 20, 2022 at 2:45 AM Tong Tiangen <tongtiangen@huawei.com> wrote=
:
>
>
>
> =E5=9C=A8 2022/4/19 17:29, Anshuman Khandual =E5=86=99=E9=81=93:
> >
> >
> > On 4/18/22 09:14, Tong Tiangen wrote:
> >> --- a/mm/page_table_check.c
> >> +++ b/mm/page_table_check.c
> >> @@ -10,6 +10,14 @@
> >>   #undef pr_fmt
> >>   #define pr_fmt(fmt)        "page_table_check: " fmt
> >>
> >> +#ifndef PMD_PAGE_SIZE
> >> +#define PMD_PAGE_SIZE       PMD_SIZE
> >> +#endif
> >> +
> >> +#ifndef PUD_PAGE_SIZE
> >> +#define PUD_PAGE_SIZE       PUD_SIZE
> >> +#endif
> >
> > Why cannot PMD_SIZE/PUD_SIZE be used on every platform instead ? What i=
s the
> > need for using PUD_PAGE_SIZE/PMD_PAGE_SIZE ? Are they different on x86 =
?
> > .
>
> Hi, Pasha=EF=BC=9A
> I checked the definitions of PMD_SIZE/PUD_SIZE and
> PUD_PAGE_SIZE/PMD_PAGE_SIZE in x86 architecture and their use outside
> the architecture(eg: in mm/, all used PMD_SIZE/PUD_SIZE), Would it be
> better to use a unified PMD_SIZE/PUD_SIZE here?

Hi Tong,

Yes, it makes sense to use PMD_SIZE/PUD_SIZE instead of
PUD_PAGE_SIZE/PMD_PAGE_SIZE in page_table_check to be inline with the
rest of the mm/

Pasha

>
> Thanks,
> Tong.