Documentation/kdump/kdump.txt: remove /dev/oldmem description

Signed-off-by: NZhang Yanfei <zhangyanfei@cn.fujitsu.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Matt Fleming <matt.fleming@intel.com>
Cc: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Documentation/kdump/kdump.txt

@@ -47,19 +47,12 @@ parameter. Optionally the size of the ELF header can also be passed
 when using the elfcorehdr=[size[KMG]@]offset[KMG] syntax.
 
 
-With the dump-capture kernel, you can access the memory image, or "old
-memory," in two ways:
-
-- Through a /dev/oldmem device interface. A capture utility can read the
-  device file and write out the memory in raw format. This is a raw dump
-  of memory. Analysis and capture tools must be intelligent enough to
-  determine where to look for the right information.
-
-- Through /proc/vmcore. This exports the dump as an ELF-format file that
-  you can write out using file copy commands such as cp or scp. Further,
-  you can use analysis tools such as the GNU Debugger (GDB) and the Crash
-  tool to debug the dump file. This method ensures that the dump pages are
-  correctly ordered.
+With the dump-capture kernel, you can access the memory image through
+/proc/vmcore. This exports the dump as an ELF-format file that you can
+write out using file copy commands such as cp or scp. Further, you can
+use analysis tools such as the GNU Debugger (GDB) and the Crash tool to
+debug the dump file. This method ensures that the dump pages are correctly
+ordered.
 
 
 Setup and Installation
@@ -423,18 +416,6 @@ the following command:
 
    cp /proc/vmcore <dump-file>
 
-You can also access dumped memory as a /dev/oldmem device for a linear
-and raw view. To create the device, use the following command:
-
-    mknod /dev/oldmem c 1 12
-
-Use the dd command with suitable options for count, bs, and skip to
-access specific portions of the dump.
-
-To see the entire memory, use the following command:
-
-   dd if=/dev/oldmem of=oldmem.001
-
 
 Analysis
 ========