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Date:   Thu, 21 Apr 2022 11:05:57 +0800
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Subject: Re: [PATCH -next v4 1/4] mm: page_table_check: move
 pxx_user_accessible_page into x86
To:     Pasha Tatashin <pasha.tatashin@soleen.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>
References: <20220418034444.520928-1-tongtiangen@huawei.com>
 <20220418034444.520928-2-tongtiangen@huawei.com>
 <1671baf7-046e-7c52-183f-fd654125fd67@arm.com>
 <c376877e-53a7-d471-61bc-e7f9dd400d60@huawei.com>
 <CA+CK2bCF=7mADB=rxyHtVEd3oCZ4mxtKf=28L49uQr5oxUwYZQ@mail.gmail.com>
From:   Tong Tiangen <tongtiangen@huawei.com>
In-Reply-To: <CA+CK2bCF=7mADB=rxyHtVEd3oCZ4mxtKf=28L49uQr5oxUwYZQ@mail.gmail.com>
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在 2022/4/21 0:44, Pasha Tatashin 写道:
> On Wed, Apr 20, 2022 at 2:45 AM Tong Tiangen <tongtiangen@huawei.com> wrote:
>>
>>
>>
>> 在 2022/4/19 17:29, Anshuman Khandual 写道:
>>>
>>>
>>> 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 is the
>>> need for using PUD_PAGE_SIZE/PMD_PAGE_SIZE ? Are they different on x86 ?
>>> .
>>
>> Hi, Pasha：
>> 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
> 
Hi Pasha and Anshuman:

OK, Functional correctness is not affected here, i plan to optimize this 
point after this patchset is merged.

Tong.

>>
>> Thanks,
>> Tong.
> .