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Message-ID: <af0faace0811111736o4b6904acx9c25e06d4ebf3421@mail.gmail.com>
Date: Wed, 12 Nov 2008 09:36:43 +0800
From: "Pan ruochen" <panruochen@gmail.com>
To: "Peter Zijlstra" <peterz@infradead.org>
Subject: Re: How kernel applies LRU to swap out physical pages?
Cc: "KOSAKI Motohiro" <kosaki.motohiro@jp.fujitsu.com>,
       linux-kernel@vger.kernel.org
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Thanks to all, I've have a study.

2008/11/11 Peter Zijlstra <peterz@infradead.org>:
> On Tue, 2008-11-11 at 18:56 +0900, KOSAKI Motohiro wrote:
>> > On Tue, 2008-11-11 at 16:22 +0800, Pan ruochen wrote:
>> > > Hi All,
>> > > I'm reading the linux kernel 2.6.14. But can't understand how LRU algorithm
>> > > is applied to page swapping. what is the 'USED' of LRU referred to? The
>> > > reference counter which the page is mapped by processes, or the frequency that
>> > > CPU reads/writes in the page. In common sense, the LRU algorithm will be more
>> > > optimal for the second case. But it depends on CPU capability.
>> > > I will be very appreciated if somebody can explain that in details.
>> >
>> > We don't actually use LRU but something like CLOCK.
>
> FWIW in case you hadn't found it yet:
>
>  http://en.wikipedia.org/wiki/Page_replacement_algorithm
>
> is a fairly decent page on the subject.
>