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authorNicolas Pitre <nico@cam.org>2008-09-19 00:36:12 -0400
committerGary King <GKing@nvidia.com>2010-02-02 15:57:34 -0800
commit7ebec3eb6c81b9a18e0e0478686c51804a8f3c2c (patch)
tree40b02241c8769080d6d0d6e8666a8fb99a2d3950
parent04c78b2033666f80a947e67bc93f820d5b90df3f (diff)
[ARM] add CONFIG_HIGHMEM option
Here it is... HIGHMEM for the ARM architecture. :-) If you don't have enough ram for highmem pages to be allocated and still want to test this, then the cmdline option "vmalloc=" can be used with a value large enough to force the highmem threshold down. Successfully tested on a Marvell DB-78x00-BP Development Board with 2 GB of RAM. Signed-off-by: Nicolas Pitre <nico@marvell.com>
-rw-r--r--arch/arm/Kconfig17
1 files changed, 17 insertions, 0 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 166a7eadf990..434e3dd75c91 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1075,6 +1075,23 @@ config NODES_SHIFT
default "2"
depends on NEED_MULTIPLE_NODES
+config HIGHMEM
+ bool "High Memory Support (EXPERIMENTAL)"
+ depends on MMU && EXPERIMENTAL
+ help
+ The address space of ARM processors is only 4 Gigabytes large
+ and it has to accommodate user address space, kernel address
+ space as well as some memory mapped IO. That means that, if you
+ have a large amount of physical memory and/or IO, not all of the
+ memory can be "permanently mapped" by the kernel. The physical
+ memory that is not permanently mapped is called "high memory".
+
+ Depending on the selected kernel/user memory split, minimum
+ vmalloc space and actual amount of RAM, you may not need this
+ option which should result in a slightly faster kernel.
+
+ If unsure, say n.
+
source "mm/Kconfig"
config LEDS