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Date: Wed, 27 Feb 2008 09:50:05 +0900
From: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
To: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
       linux-kernel@vger.kernel.org, linux-mm@kvack.org,
       Balbir Singh <balbir@linux.vnet.ibm.com>,
       Rik van Riel <riel@redhat.com>,
       Lee Schermerhorn <Lee.Schermerhorn@hp.com>,
       Nick Piggin <npiggin@suse.de>
Subject: Re: [RFC][PATCH] page reclaim throttle take2
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On Tue, 26 Feb 2008 22:18:38 +0100
Peter Zijlstra <a.p.zijlstra@chello.nl> wrote:

> > +out:
> > +	atomic_dec(&zone->nr_reclaimers);
> > +	wake_up_all(&zone->reclaim_throttle_waitq);
> > +
> > +	return ret;
> > +}
> 
> Would it be possible - and worthwhile - to make this FIFO fair?
> 
I think it doesn't make sense for fairness.

IMHO, this functionality is an unfair one in nature. While someone is
reclaiming pages, other processes can get a newly reclaimed page without
calling try_to_free_page.

For high-priority processes, 

1. avoiding diving into try_to_free_pages if it's congested.
2. just waiting for that someone relcaim pages and grab it ASAP

maybe good for quick work. 

Thanks,
-Kame