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Date: Wed, 15 Feb 2017 16:13:44 +0900
From: Minchan Kim <minchan@kernel.org>
To: Yisheng Xie <xieyisheng1@huawei.com>
CC: <akpm@linux-foundation.org>, <ngupta@vflare.org>,
        <sergey.senozhatsky.work@gmail.com>, <linux-mm@kvack.org>,
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Subject: Re: [RFC] mm/zsmalloc: remove redundant SetPagePrivate2 in
 create_page_chain
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On Tue, Feb 14, 2017 at 08:48:29PM +0800, Yisheng Xie wrote:
> We had used page->lru to link the component pages (except the first
> page) of a zspage, and used INIT_LIST_HEAD(&page->lru) to init it.
> Therefore, to get the last page's next page, which is NULL, we had to
> use page flag PG_Private_2 to identify it.
> 
> But now, we use page->freelist to link all of the pages in zspage and
> init the page->freelist as NULL for last page, so no need to use
> PG_Private_2 anymore.
> 
> This patch is to remove redundant SetPagePrivate2 in create_page_chain
> and ClearPagePrivate2 in reset_page(). Maybe can save few cycles for
> migration of zsmalloc page :)
> 
> Signed-off-by: Yisheng Xie <xieyisheng1@huawei.com>
Acked-by: Minchan Kim <minchan@kernel.org>

Thanks, Yisheng!