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Date: Fri, 17 Dec 2010 13:37:39 +0900
Message-ID: <AANLkTin-JUMNvoTubuVawsJLi89rG84K6EG3EBuc5gsK@mail.gmail.com>
Subject: Re: [PATCH] mm: add replace_page_cache_page() function
From: Minchan Kim <minchan.kim@gmail.com>
To: Hugh Dickins <hughd@google.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>, akpm@linux-foundation.org,
        linux-fsdevel@vger.kernel.org, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org
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On Fri, Dec 17, 2010 at 11:10 AM, Hugh Dickins <hughd@google.com> wrote:
> On Fri, 17 Dec 2010, Minchan Kim wrote:
>> On Fri, Dec 17, 2010 at 10:21 AM, Hugh Dickins <hughd@google.com> wrote:
>> >
>> > I disagree with you there: I like the way Miklos made it symmetric,
>> > I like the way delete_from_swap_cache drops the swap cache reference,
>> > I dislike the way remove_from_page_cache does not - I did once try to
>> > change that, but did a bad job, messed up reiserfs or reiser4 I forget
>> > which, retreated in shame.
>>
>> I agree symmetric is good. I just said current fact which is that
>> remove_from_page_cache doesn't release ref.
>> So I thought we have to match current semantic to protect confusing.
>> Okay. I will not oppose current semantics.
>> Instead of it, please add it (ex, caller should hold the page
>> reference) in function description.
>>
>> I am happy to hear that you tried it.
>> Although it is hard, I think it's very valuable thing.
>> Could you give me hint to googling your effort and why it is failed?
>
> http://lkml.org/lkml/2004/10/24/140

Thanks.

Now we have only 3 callers of remove_from_page_cache in mmtom.

1. truncate_huge_page
2. shmem_writepage
3. truncate_complete_page
4. fuse_try_move_page

It seems all of caller hold the page reference so It's ok to change
the semantic of remove_from_page_cache.
Okay. I will do that.

>
> Hugh
>


-- 
Kind regards,
Minchan Kim
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