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Date: Thu, 07 Apr 2005 12:11:13 +0300
From: Leonid Podolny <leonid99@mail.ru>
Subject: Bug in mm.h?
To: lkml <linux-kernel@vger.kernel.org>
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I fail to understand whether the following is a bug. From what I see, if
the page is reserved, page->count is not decreased. The order of the
conditions should be reversed.

>>From mm.h:

static inline void put_page(struct page *page)
{
        if (!PageReserved(page) && put_page_testzero(page))
                __page_cache_release(page);
}

static inline void get_page(struct page *page)
{
        atomic_inc(&page->_count);
}

#define put_page_testzero(p)                            \
        ({                                              \
                BUG_ON(page_count(p) == 0);             \
                atomic_add_negative(-1, &(p)->_count);  \
        })