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Reply-To: "Hillf Danton" <hillf.zj@alibaba-inc.com>
From: "Hillf Danton" <hillf.zj@alibaba-inc.com>
To: "'Huang, Ying'" <ying.huang@intel.com>,
        "'Andrew Morton'" <akpm@linux-foundation.org>
Cc: <tim.c.chen@intel.com>, <dave.hansen@intel.com>,
        <andi.kleen@intel.com>, <aaron.lu@intel.com>, <linux-mm@kvack.org>,
        <linux-kernel@vger.kernel.org>, "'Hugh Dickins'" <hughd@google.com>,
        "'Shaohua Li'" <shli@kernel.org>, "'Minchan Kim'" <minchan@kernel.org>,
        "'Rik van Riel'" <riel@redhat.com>,
        "'Andrea Arcangeli'" <aarcange@redhat.com>,
        "'Kirill A . Shutemov'" <kirill.shutemov@linux.intel.com>
References: <20161028055608.1736-1-ying.huang@intel.com> <20161028055608.1736-7-ying.huang@intel.com>
In-Reply-To: <20161028055608.1736-7-ying.huang@intel.com>
Subject: Re: [PATCH -v4 RESEND 6/9] mm, THP, swap: Support to add/delete THP to/from swap cache
Date: Fri, 28 Oct 2016 16:08:46 +0800
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On Friday, October 28, 2016 1:56 PM Huang, Ying wrote:
> 
> @@ -109,9 +118,16 @@ int __add_to_swap_cache(struct page *page, swp_entry_t entry)
>  		 * So add_to_swap_cache() doesn't returns -EEXIST.
>  		 */
>  		VM_BUG_ON(error == -EEXIST);
> -		set_page_private(page, 0UL);
>  		ClearPageSwapCache(page);
> -		put_page(page);
> +		set_page_private(cur_page, 0UL);
> +		while (i--) {
> +			cur_page--;
> +			cur_entry.val--;
> +			set_page_private(cur_page, 0UL);
> +			radix_tree_delete(&address_space->page_tree,
> +					  swp_offset(cur_entry));
> +		}

Pull pages out of radix tree with tree lock held?

> +		page_ref_sub(page, nr);
>  	}
> 
>  	return error;
>