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Date: Fri, 18 Dec 2009 13:26:39 -0800
From: "H. Peter Anvin" <hpa@zytor.com>
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To: Yinghai Lu <yinghai@kernel.org>
CC: Ingo Molnar <mingo@elte.hu>, Thomas Gleixner <tglx@linutronix.de>,
       Andrew Morton <akpm@linux-foundation.org>,
       Jesse Barnes <jbarnes@virtuousgeek.org>,
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Subject: Re: [PATCH 1/9] x86: move range related operation to one file
References: <4B2B4C19.6010402@kernel.org> <4B2B4F85.5030901@kernel.org> <4B2BE1BF.60803@zytor.com> <4B2BE348.207@kernel.org>
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On 12/18/2009 12:17 PM, Yinghai Lu wrote:
> 
> yes here is we have [start, end] instead of [start, end)
> 
> those range operation is used for one purpose:
> add several ranges, and subtract some other ranges, it will take out overlap between those two sets.
> and leave out the range that could be used.
> 
> and it is array based...for early stage.
> 

Yes.  We should be able to use the *exact same code* for the e820
ranges, using the e820 attribute as the attribute parameters, and a
simple boolean for the case where all you want is inclusion/exclusion.
And yes, I agree array based is the right thing to do for the early code.

Note that my array-based version only had an insert operation, no delete
operation -- that is because the delete operation is simply an insert
operation of attribute 0.

	-hpa