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Date: Thu, 14 Nov 2019 13:32:37 +0100
From: Christoph Hellwig <hch@lst.de>
To: Dan Williams <dan.j.williams@intel.com>
Cc: jhubbard@nvidia.com, Jan Kara <jack@suse.cz>,
	Christoph Hellwig <hch@lst.de>, Ira Weiny <ira.weiny@intel.com>,
	=?iso-8859-1?B?Suly9G1l?= Glisse <jglisse@redhat.com>,
	linux-nvdimm@lists.01.org, linux-kernel@vger.kernel.org,
	linux-mm@kvack.org
Subject: Re: [PATCH v2] mm: Cleanup __put_devmap_managed_page() vs
 ->page_free()
Message-ID: <20191114123237.GA31940@lst.de>
References: <157371938291.3055029.12105459405251950438.stgit@dwillia2-desk3.amr.corp.intel.com>
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On Thu, Nov 14, 2019 at 12:20:13AM -0800, Dan Williams wrote:
> +	if (count > 1) {
> +		/* still busy */
> +		return;
> +	} else if (count == 0) {
> +		/* only triggered by the dev_pagemap shutdown path */
> +		__put_page(page);
> +		return;
> +	} else if (!is_device_private_page(page)) {
> +		/* notify page idle for dax */
> +		wake_up_var(&page->_refcount);
> +		return;
> +	}

No need for an else after a return.