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Date: Tue, 1 Mar 2011 13:11:46 +0900
From: Minchan Kim <minchan.kim@gmail.com>
To: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>, Andrea Arcangeli <aarcange@redhat.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Arthur Marsh <arthur.marsh@internode.on.net>,
        Clemens Ladisch <cladisch@googlemail.com>,
        Linux-MM <linux-mm@kvack.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 2/2] mm: compaction: Minimise the time IRQs are
 disabled while isolating pages for migration
Message-ID: <20110301041146.GA2107@barrios-desktop>
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On Tue, Mar 01, 2011 at 08:42:09AM +0900, KAMEZAWA Hiroyuki wrote:
> On Mon, 28 Feb 2011 10:18:27 +0000
> Mel Gorman <mel@csn.ul.ie> wrote:
> 
> > > BTW, can't we drop disable_irq() from all lru_lock related codes ?
> > > 
> > 
> > I don't think so - at least not right now. Some LRU operations such as LRU
> > pagevec draining are run from IPI which is running from an interrupt so
> > minimally spin_lock_irq is necessary.
> > 
> 
> pagevec draining is done by workqueue(schedule_on_each_cpu()). 
> I think only racy case is just lru rotation after writeback.

put_page still need irq disable.


> 
> Thanks,
> -Kame
> 
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-- 
Kind regards,
Minchan Kim
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