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Date: Thu, 29 Jul 2010 01:29:53 +0900
From: Minchan Kim <minchan.kim@gmail.com>
To: Wu Fengguang <fengguang.wu@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
        Andy Whitcroft <apw@shadowen.org>, Rik van Riel <riel@redhat.com>,
        KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
        Mel Gorman <mel@csn.ul.ie>, Christoph Hellwig <hch@infradead.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>,
        "linux-mm@kvack.org" <linux-mm@kvack.org>,
        Dave Chinner <david@fromorbit.com>,
        Chris Mason <chris.mason@oracle.com>, Nick Piggin <npiggin@suse.de>,
        Johannes Weiner <hannes@cmpxchg.org>,
        KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
        Andrea Arcangeli <aarcange@redhat.com>, Andreas Mohr <andi@lisas.de>,
        Bill Davidsen <davidsen@tmr.com>, Ben Gamari <bgamari.foss@gmail.com>
Subject: Re: [PATCH] vmscan: remove wait_on_page_writeback() from pageout()
Message-ID: <20100728162953.GB5401@barrios-desktop>
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On Wed, Jul 28, 2010 at 04:46:54PM +0800, Wu Fengguang wrote:
> And the wait page-by-page behavior of pageout(SYNC) will lead to very
> long stall time if running into some range of dirty pages. So it's bad
> idea anyway to call wait_on_page_writeback() inside pageout().

Although we remove it in pageout, shrink_page_list still has it.
So it would result in long stall. And it is for lumpy reclaim which 
means it's a trade-off, I think. 

-- 
Kind regards,
Minchan Kim
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