From 053a96ca11a9785a7e63fc89eed4514a6446ec58 Mon Sep 17 00:00:00 2001 From: Nicolas Pitre Date: Fri, 19 Sep 2008 00:36:12 -0400 Subject: [PATCH] [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 --- arch/arm/Kconfig | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index dbfdf87f993..2b28786b387 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -915,6 +915,23 @@ 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 -- 2.41.0