[PATCH] enable VMSPLIT for highmem kernels

From: Dave Hansen
Date: Fri Aug 04 2006 - 17:36:46 EST

I'll assume that the complete lack of commenting on this patch
mean that everyone agrees with me. :) Time for -mm I guess.


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

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

Signed-off-by: Dave Hansen <haveblue@xxxxxxxxxx>

lxc-dave/arch/i386/Kconfig | 3 ++-
1 files changed, 2 insertions(+), 1 deletion(-)

diff -puN arch/i386/Kconfig~split-for-pae arch/i386/Kconfig
--- lxc/arch/i386/Kconfig~split-for-pae 2006-08-03 09:01:32.000000000 -0700
+++ lxc-dave/arch/i386/Kconfig 2006-08-04 14:38:34.000000000 -0700
@@ -497,7 +497,7 @@ config HIGHMEM64G

- depends on EXPERIMENTAL && !X86_PAE
+ depends on EXPERIMENTAL
prompt "Memory split" if EMBEDDED
default VMSPLIT_3G
@@ -519,6 +519,7 @@ choice
config VMSPLIT_3G
bool "3G/1G user/kernel split"
+ depends on !HIGHMEM
bool "3G/1G user/kernel split (for full 1G low memory)"
config VMSPLIT_2G
bool "2G/2G user/kernel split"
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