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Subject: Re: How kernel applies LRU to swap out physical pages?
From: Peter Zijlstra <peterz@infradead.org>
To: Pan ruochen <panruochen@gmail.com>
Cc: linux-kernel@vger.kernel.org
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Date: Tue, 11 Nov 2008 09:57:25 +0100
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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.