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Message-ID: <86802c440901132207l433227d9nf149506012a5721e@mail.gmail.com>
Date: Tue, 13 Jan 2009 22:07:26 -0800
From: "Yinghai Lu" <yinghai@kernel.org>
To: "James Kirin" <james.kirin40@gmail.com>
Subject: Re: memory beyond4GB invisible to the system even though CONFIG_HIGHMEM64G=y
Cc: "Roland Dreier" <rdreier@cisco.com>, linux-kernel@vger.kernel.org
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References: <baeb34bc0901131746n33cd536co331e32361df2fb72@mail.gmail.com>
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On Tue, Jan 13, 2009 at 7:10 PM, James Kirin <james.kirin40@gmail.com> wrote:
> Thank you for your reply, Roland. Unfortunately, this continues
> happening after having installed the most recent version of the BIOS
> available from Dell.
>
> I understand this is a problem in the BIOS and not the kernel, but is
> there a way to have the kernel work around this bug in the BIOS and
> make that memory accessible? Eg,
>
> http://www.gossamer-threads.com/lists/linux/kernel/991748#991748

please do
1. boot linux with "disable_mtrr_trim" in grub.conf etc
2. after booting input:
echo "base=0x100000000 size=0x20000000 type=write-back" >/proc/mtrr

later you could put that line in one scripts and call it from inittab
# grep mtrrfixup /etc/inittab
mtrr:345:once:/root/mtrrfixup.sh

YH