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Date: Fri, 22 Jun 2007 01:02:05 +0200
From: Peter Rabbitson <rabbit@rabbit.us>
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To: "H. Peter Anvin" <hpa@zytor.com>
CC: linux-kernel@vger.kernel.org
Subject: Re: Terrible IO performance when using 4GB of RAM on a 32 bit machine
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H. Peter Anvin wrote:
> Peter Rabbitson wrote:
>> I have captured dmesg output without mem[5], with mem=3900M[6] and
>> mem=2048M[7].
>>
> 
> What does /proc/mtrr look like in the two cases?
> 

Identical for mem=3900 and without it.

reg00: base=0x00000000 (   0MB), size=2048MB: write-back, count=1 

reg01: base=0x80000000 (2048MB), size=1024MB: write-back, count=1 

reg02: base=0xc0000000 (3072MB), size= 512MB: write-back, count=1 

reg03: base=0xe0000000 (3584MB), size= 256MB: write-back, count=1 

reg04: base=0xf0000000 (3840MB), size= 128MB: write-back, count=1 

reg05: base=0xf8000000 (3968MB), size=  32MB: write-back, count=1 


Peter