Subject: Re: [PATCH] mm: move huge_pmd_set_accessed out of huge_memory.c
To: "Kirill A. Shutemov" <kirill@shutemov.name>
References: <1461176698-9714-1-git-send-email-yang.shi@linaro.org>
 <5717EDDB.1060704@linaro.org> <20160421073050.GA32611@node.shutemov.name>
 <57195A87.4050408@linaro.org> <20160422094815.GB7336@node.shutemov.name>
Cc: akpm@linux-foundation.org, kirill.shutemov@linux.intel.com,
        aarcange@redhat.com, hughd@google.com, mgorman@suse.de,
        linux-kernel@vger.kernel.org, linux-mm@kvack.org,
        linaro-kernel@lists.linaro.org
From: "Shi, Yang" <yang.shi@linaro.org>
Message-ID: <0357941c-d7ce-3ba9-c24f-9d2599429a8a@linaro.org>
Date: Fri, 29 Apr 2016 11:09:36 -0700
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On 4/22/2016 2:48 AM, Kirill A. Shutemov wrote:
> On Thu, Apr 21, 2016 at 03:56:07PM -0700, Shi, Yang wrote:
>> On 4/21/2016 12:30 AM, Kirill A. Shutemov wrote:
>>> On Wed, Apr 20, 2016 at 02:00:11PM -0700, Shi, Yang wrote:
>>>> Hi folks,
>>>>
>>>> I didn't realize pmd_* functions are protected by
>>>> CONFIG_TRANSPARENT_HUGEPAGE on the most architectures before I made this
>>>> change.
>>>>
>>>> Before I fix all the affected architectures code, I want to check if you
>>>> guys think this change is worth or not?
>>>>
>>>> Thanks,
>>>> Yang
>>>>
>>>> On 4/20/2016 11:24 AM, Yang Shi wrote:
>>>>> huge_pmd_set_accessed is only called by __handle_mm_fault from memory.c,
>>>>> move the definition to memory.c and make it static like create_huge_pmd and
>>>>> wp_huge_pmd.
>>>>>
>>>>> Signed-off-by: Yang Shi <yang.shi@linaro.org>
>>>
>>> On pte side we have the same functionality open-coded. Should we do the
>>> same for pmd? Or change pte side the same way?
>>
>> Sorry, I don't quite understand you. Do you mean pte_* functions?
>
> See handle_pte_fault(), we do the same for pte there what
> huge_pmd_set_accessed() does for pmd.

Thanks for directing to this code.

>
> I think we should be consistent here: either both are abstructed into
> functions or both open-coded.

I'm supposed functions sound better. However, do_wp_page has to be 
called with pte lock acquired. So, the abstracted function has to call it.

Thanks,
Yang


>