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Date: Tue, 08 Feb 2005 09:36:20 -0600
From: Chris Friesen <cfriesen@nortel.com>
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To: Dan Malek <dan@embeddededge.com>
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Cc: linuxppc-dev list <linuxppc-dev@ozlabs.org>,
	Arjan van de Ven <arjan@infradead.org>,
	Linux Kernel list <linux-kernel@vger.kernel.org>,
	linuxppc64-dev <linuxppc64-dev@ozlabs.org>
Subject: Re: question on symbol exports
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Dan Malek wrote:
> 
> On Feb 7, 2005, at 4:35 PM, Benjamin Herrenschmidt wrote:
> 
>> Interesting... more than no swap, you must also make sure you have no
>> r/w mmap'ed file (which are technically equivalent to swap).
> 
> 
> Yeah, I kinda had a similar thought.  Just because you aren't
> swapping doesn't mean the VM subsystem isn't looking at dirty bits,
> too.  It could potentially steal a page that it thinks can be replaced
> from either a zero-fill or reading again from persistent storage.

In our existing case, the app also mlock()s the pages in question.  This 
should get around these two possible sources of inaccuracy.

Chris