[PATCH] x86: enable VMSPLIT for highmem kernels

The current VMSPLIT Kconfig option is disabled whenever highmem is on.
This is a bit screwy because the people who need to change VMSPLIT the most
tend to be the ones with highmem and constrained lowmem.

So, remove the highmem dependency.  But, re-include the dependency for the
"full 1GB of lowmem" option.  You can't have the full 1GB of lowmem and
highmem because of the need for the vmalloc(), kmap(), etc...  areas.

I thought there would be at least a bit of tweaking to do to
get it to work, but everything seems OK.

Boot tested on a 4GB x86 machine, and a 12GB 3-node NUMA-Q:

elm3b82:~# cat /proc/meminfo
MemTotal:      3695412 kB
MemFree:       3659540 kB
...
LowTotal:      2909008 kB
LowFree:       2892324 kB
...
elm3b82:~# zgrep PAE /proc/config.gz
CONFIG_X86_PAE=y

larry:~# cat /proc/meminfo
MemTotal:     11845900 kB
MemFree:      11786748 kB
...
LowTotal:      2855180 kB
LowFree:       2830092 kB

Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 2 insertions, 1 deletions

diff --git a/arch/i386/Kconfig b/arch/i386/Kconfig
index 1f83efb7a60e..6189b0c28d6f 100644
--- a/arch/i386/Kconfig
+++ b/arch/i386/Kconfig
@@ -494,7 +494,7 @@ config HIGHMEM64G
 endchoice
 
 choice
-        depends on EXPERIMENTAL && !X86_PAE
+        depends on EXPERIMENTAL
         prompt "Memory split" if EMBEDDED
         default VMSPLIT_3G
         help
@@ -516,6 +516,7 @@ choice
         config VMSPLIT_3G
                 bool "3G/1G user/kernel split"
         config VMSPLIT_3G_OPT
+                depends on !HIGHMEM
                 bool "3G/1G user/kernel split (for full 1G low memory)"
         config VMSPLIT_2G
                 bool "2G/2G user/kernel split"