kernel-parameters.txt: document memmap option better

Provide example for memmap exclude option (it is slightly strange and
non-trivial) and provide nice small HOWTO for people with bad memory.

Signed-off-by: Jan-Simon Moeller <dl9pf@gmx.de>
Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 650b0d8aa89b7bde17ca17c1ee54ad37e57f7480..508e2a2c98644ad6c4ee70e59a33191af9af541e 100644 (file)
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1130,6 +1130,10 @@ and is between 256 and 4096 characters. It is defined in the file
        memmap=nn[KMG]$ss[KMG]
                        [KNL,ACPI] Mark specific memory as reserved.
                        Region of memory to be used, from ss to ss+nn.
+                       Example: Exclude memory from 0x18690000-0x1869ffff
+                                memmap=64K$0x18690000
+                                or
+                                memmap=0x10000$0x18690000
 
        meye.*=         [HW] Set MotionEye Camera parameters
                        See Documentation/video4linux/meye.txt.