From: Li Haifeng <omycle@gmail.com>
To: linux-mm@kvack.org
Subject: Qestion about page->_count and page reclaim
Date: Mon, 4 Feb 2013 18:34:54 +0800 [thread overview]
Message-ID: <CAFNq8R5w7qwJ2j9VQXfw_ALZKWu_ZYaMkbd3owL5N9VOTeTVAQ@mail.gmail.com> (raw)
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Hi, all in kernel.
The page->_count is the page frame's usage count.
When page is allocated, the page will be refcounted, and page->_cout will
be set 1.
After be allocated from buddy system, the page will be used by process.
get_page and put_page/put_page_testzero will used in pairs. is it right?
When the page is reclaimed to buddy system, the page->_count should be 0.
However, Because the initialization of page->_count is 1, get_page() and
put_page() is called in pairs, I coufused how page->_count will be 0?
Thanks.
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reply other threads:[~2013-02-04 10:34 UTC|newest]
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