[PATCH] x86: add a bootparameter to reserve high linear address space

Add a boot parameter to reserve high linear address space for hypervisors.
This is necessary to allow dynamically loaded hypervisor modules, which might
not happen until userspace is already running, and also provides a useful tool
to benchmark the performance impact of reduced lowmem address space.

Signed-off-by: Zachary Amsden <zach@vmware.com>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 5 insertions, 0 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 71d05f481727..766abdab94e7 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1363,6 +1363,11 @@ running once the system is up.
 
         reserve=        [KNL,BUGS] Force the kernel to ignore some iomem area
 
+        reservetop=     [IA-32]
+                        Format: nn[KMG]
+                        Reserves a hole at the top of the kernel virtual
+                        address space.
+
         resume=         [SWSUSP]
                         Specify the partition device for software suspend