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Date:   Thu, 14 Oct 2021 17:52:35 +0100
From:   Matthew Wilcox <willy@infradead.org>
To:     Alex Sierra <alex.sierra@amd.com>
Cc:     akpm@linux-foundation.org, Felix.Kuehling@amd.com,
        linux-mm@kvack.org, rcampbell@nvidia.com,
        linux-ext4@vger.kernel.org, linux-xfs@vger.kernel.org,
        amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org,
        hch@lst.de, jgg@nvidia.com, jglisse@redhat.com, apopple@nvidia.com
Subject: Re: [PATCH v1 2/2] mm: remove extra ZONE_DEVICE struct page refcount
Message-ID: <YWhgU2vJfTN6XOyl@casper.infradead.org>
References: <20211014153928.16805-1-alex.sierra@amd.com>
 <20211014153928.16805-3-alex.sierra@amd.com>
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On Thu, Oct 14, 2021 at 10:39:28AM -0500, Alex Sierra wrote:
> From: Ralph Campbell <rcampbell@nvidia.com>
> 
> ZONE_DEVICE struct pages have an extra reference count that complicates the
> code for put_page() and several places in the kernel that need to check the
> reference count to see that a page is not being used (gup, compaction,
> migration, etc.). Clean up the code so the reference count doesn't need to
> be treated specially for ZONE_DEVICE.
> 
> Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
> Signed-off-by: Alex Sierra <alex.sierra@amd.com>
> Reviewed-by: Christoph Hellwig <hch@lst.de>

Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>