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	<1359365068-10147-7-git-send-email-kirill.shutemov@linux.intel.com>
Date: Tue, 29 Jan 2013 20:26:09 +0800
Message-ID: <CAJd=RBCCmDrS=866SMEezcsCCX3vrfnusUFoyaRQb+c=JCkFEg@mail.gmail.com>
Subject: Re: [PATCH, RFC 06/16] thp, mm: rewrite add_to_page_cache_locked() to
 support huge pages
From: Hillf Danton <dhillf@gmail.com>
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Sender: owner-linux-mm@kvack.org
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To: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>, Andrew Morton <akpm@linux-foundation.org>, Al Viro <viro@zeniv.linux.org.uk>, Wu Fengguang <fengguang.wu@intel.com>, Jan Kara <jack@suse.cz>, Mel Gorman <mgorman@suse.de>, linux-mm@kvack.org, Andi Kleen <ak@linux.intel.com>, Matthew Wilcox <matthew.r.wilcox@intel.com>, "Kirill A. Shutemov" <kirill@shutemov.name>, linux-fsdevel <linux-fsdevel@vger.kernel.org>, LKML <linux-kernel@vger.kernel.org>

On Mon, Jan 28, 2013 at 5:24 PM, Kirill A. Shutemov
<kirill.shutemov@linux.intel.com> wrote:
> +       page_cache_get(page);
> +       spin_lock_irq(&mapping->tree_lock);
> +       page->mapping = mapping;
> +       if (PageTransHuge(page)) {
> +               int i;
> +               for (i = 0; i < HPAGE_CACHE_NR; i++) {
> +                       page_cache_get(page + i);
> +                       page[i].index = offset + i;
> +                       error = radix_tree_insert(&mapping->page_tree,
> +                                       offset + i, page + i);
> +                       if (error) {
> +                               page_cache_release(page + i);
> +                               break;
> +                       }

Is page count balanced with the following?


@@ -168,6 +180,9 @@ void delete_from_page_cache(struct page *page)

        if (freepage)
                freepage(page);
+       if (PageTransHuge(page))
+               for (i = 1; i < HPAGE_CACHE_NR; i++)
+                       page_cache_release(page);
        page_cache_release(page);

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