linux-kernel - Re: Use of memmap= to forcibly recover memory in 3GB-4GB range

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Date:	Wed, 16 Jan 2013 19:24:01 -0500
From:	Alex Villacís Lasso <a_villacis@...osanto.com>
To:	Yinghai Lu <yinghai@...nel.org>
CC:	linux-kernel@...r.kernel.org
Subject: Re: Use of memmap= to forcibly recover memory in 3GB-4GB range -
 is this safe?

El 16/01/13 02:11, Yinghai Lu escribió:
> On Tue, Jan 15, 2013 at 5:47 PM, Alex Villacís Lasso
> <a_villacis@...osanto.com> wrote:
>> [    0.000000] e820: BIOS-provided physical RAM map:
>> [    0.000000] BIOS-e820: [mem 0x0000000000000000-0x000000000009f3ff] usable
>> [    0.000000] BIOS-e820: [mem 0x000000000009f400-0x000000000009ffff]
>> reserved
>> [    0.000000] BIOS-e820: [mem 0x00000000000f0000-0x00000000000fffff]
>> reserved
>> [    0.000000] BIOS-e820: [mem 0x0000000000100000-0x00000000cf58ffff] usable
>> [    0.000000] BIOS-e820: [mem 0x00000000cf590000-0x00000000cf5e2fff] ACPI
>> NVS
>> [    0.000000] BIOS-e820: [mem 0x00000000cf5e3000-0x00000000cf5effff] ACPI
>> data
>> [    0.000000] BIOS-e820: [mem 0x00000000cf5f0000-0x00000000cf5fffff]
>> reserved
>> [    0.000000] BIOS-e820: [mem 0x00000000e0000000-0x00000000efffffff]
>> reserved
>> [    0.000000] BIOS-e820: [mem 0x00000000fec00000-0x00000000ffffffff]
>> reserved
>> [    0.000000] NX (Execute Disable) protection: active
> ..
>> [    0.000000] original variable MTRRs
>> [    0.000000] reg 0, base: 4GB, range: 512MB, type WB
>> [    0.000000] reg 1, base: 4608MB, range: 256MB, type WB
>> [    0.000000] reg 2, base: 0GB, range: 2GB, type WB
>> [    0.000000] reg 3, base: 2GB, range: 1GB, type WB
>> [    0.000000] reg 4, base: 3GB, range: 256MB, type WB
>> [    0.000000] reg 5, base: 3319MB, range: 1MB, type UC
>> [    0.000000] reg 6, base: 3320MB, range: 8MB, type UC
>> [    0.000000] reg 7, base: 3318MB, range: 1MB, type UC
>> [    0.000000] total RAM covered: 4086M
> Can you apply attached debug patch to see if the raw e820 is right from BIOS ?
>
> Yinghai
Done. The output is attached. I see no difference between raw and 
sanitized maps.

View attachment "dmesg.txt" of type "text/plain" (63143 bytes)