linux-kernel - Re: Document hadling of bad memory

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Message-Id: <20081201105625.25ee9f32.randy.dunlap@oracle.com>
Date:	Mon, 1 Dec 2008 10:56:25 -0800
From:	Randy Dunlap <randy.dunlap@...cle.com>
To:	Pavel Machek <pavel@...e.cz>
Cc:	kernel list <linux-kernel@...r.kernel.org>, mtk.manpages@...il.com,
	dl9pf@....de, rdunlap@...otime.net, linux-doc@...r.kernel.org,
	Andrew Morton <akpm@...l.org>,
	Trivial patch monkey <trivial@...nel.org>
Subject: Re: Document hadling of bad memory

On Wed, 26 Nov 2008 17:15:21 +0100 Pavel Machek wrote:

> Document how to deal with bad memory reported with memtest.
> 
> Signed-off-by: Pavel Machek <pavel@...e.cz>
> 
> diff --git a/Documentation/bad_memory.txt b/Documentation/bad_memory.txt
> new file mode 100644
> index 0000000..df84162
> --- /dev/null
> +++ b/Documentation/bad_memory.txt
> @@ -0,0 +1,45 @@
> +March 2008
> +Jan-Simon Moeller, dl9pf@....de
> +
> +
> +How to deal with bad memory e.g. reported by memtest86+ ?
> +#########################################################
> +
> +There are three possibilities I know of:
> +
> +1) Reinsert/swap the memory modules
> +
> +2) Buy new modules (best!) or try to exchange the memory
> +   if you have spare-parts
> +
> +3) Use BadRAM or memmap
> +
> +This Howto is about number 3) .

No space between 3) and '.'.

> +
> +
> +BadRAM
> +######
> +BadRAM is the actively developed and available as kernel-patch
> +here:  http://rick.vanrein.org/linux/badram/
> +
> +For more details see the BadRAM documentation.
> +
> +memmap
> +######
> +
> +memmap is already in the kernel and usable as kernel-parameter at

                                                 a kernel parameter at

> +boot-time.  Its syntax is slightly strange and you may need to

   boot time.

> +calculate the values by yourself!

s/!/./

> +
> +Syntax to exclude a memory area (see kernel-parameters.txt for details):
> +memmap=<size>$<address>
> +
> +Example: memtest86+ reported here errors at address 0x18691458, 0x18698424 and

s/here //

> +         some others. All had 0x1869xxxx in common, so I chose a pattern of
> +         0x18690000,0xffff0000.

What is the 0xffff0000 for?  Needs explanation.

> +
> +With the numbers of the example above:
> +memmap=64K$0x18690000
> + or
> +memmap=0x10000$0x18690000
> +

Please lose the last empty line.

and thanks for the patch/new file.

---
~Randy
--
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