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Date:   Thu, 12 Aug 2021 11:22:04 +0200
From:   Christoph Hellwig <hch@lst.de>
To:     John Hubbard <jhubbard@nvidia.com>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        Heiko Carstens <hca@linux.ibm.com>,
        Vasily Gorbik <gor@linux.ibm.com>,
        Christian Borntraeger <borntraeger@de.ibm.com>,
        LKML <linux-kernel@vger.kernel.org>, linux-mm@kvack.org,
        linux-s390@vger.kernel.org, linux-fsdevel@vger.kernel.org,
        Christoph Hellwig <hch@lst.de>,
        Matthew Wilcox <willy@infradead.org>
Subject: Re: [PATCH v2 3/3] mm/gup: Remove try_get_page(), call
 try_get_compound_head() directly
Message-ID: <20210812092204.GB4827@lst.de>
References: <20210811070542.3403116-1-jhubbard@nvidia.com> <20210811070542.3403116-4-jhubbard@nvidia.com>
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On Wed, Aug 11, 2021 at 12:05:42AM -0700, John Hubbard wrote:
> -		if (unlikely(!try_get_page(page)))
> +		if (unlikely(try_get_compound_head(page, 1) == NULL))

Why not a simple ! instead of the == NULL?

Otherwise looks good:

Reviewed-by: Christoph Hellwig <hch@lst.de>