Documentation/kernel-parameters.txt: update mem= option's spec according to its implementation

Current mem= implementation seems buggy because the specification and
implementation don't match.  The current mem= has been working for many
years and it's not buggy - it works as expected.  So we should update the
specification.

Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Cc: Rob Landley <rob@landley.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 4 insertions, 3 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index ea8e5b485576..ddd84d627185 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1503,9 +1503,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
         mem=nn[KMG]     [KNL,BOOT] Force usage of a specific amount of memory
                         Amount of memory to be used when the kernel is not able
                         to see the whole system memory or for test.
-                        [X86-32] Use together with memmap= to avoid physical
-                        address space collisions. Without memmap= PCI devices
-                        could be placed at addresses belonging to unused RAM.
+                        [X86] Work as limiting max address. Use together
+                        with memmap= to avoid physical address space collisions.
+                        Without memmap= PCI devices could be placed at addresses
+                        belonging to unused RAM.
 
         mem=nopentium   [BUGS=X86-32] Disable usage of 4MB pages for kernel
                         memory.