[patch] x86: enable GBPAGES option by default

From: Nick Piggin
Date: Wed Oct 22 2008 - 06:33:28 EST


DIRECT_GBPAGES was under DEBUG_KERNEL && EXPERIMENTAL and disabled by default.
Turn it on by default and put it under EMBEDDED.

Signed-off-by: Nick Piggin <npiggin@xxxxxxx>
---
Index: linux-2.6/arch/x86/Kconfig
===================================================================
--- linux-2.6.orig/arch/x86/Kconfig
+++ linux-2.6/arch/x86/Kconfig
@@ -946,6 +946,15 @@ config X86_PAE
config ARCH_PHYS_ADDR_T_64BIT
def_bool X86_64 || X86_PAE

+config DIRECT_GBPAGES
+ bool "Enable 1GB pages for kernel pagetables" if EMBEDDED
+ default y
+ depends on X86_64
+ help
+ Allow the kernel linear mapping to use 1GB pages on CPUs that
+ support it. This can improve the kernel's performance a tiny bit by
+ reducing TLB pressure. If in doubt, say "Y".
+
# Common NUMA Features
config NUMA
bool "Numa Memory Allocation and Scheduler Support (EXPERIMENTAL)"
Index: linux-2.6/arch/x86/Kconfig.debug
===================================================================
--- linux-2.6.orig/arch/x86/Kconfig.debug
+++ linux-2.6/arch/x86/Kconfig.debug
@@ -114,18 +114,6 @@ config DEBUG_RODATA
data. This is recommended so that we can catch kernel bugs sooner.
If in doubt, say "Y".

-config DIRECT_GBPAGES
- bool "Enable gbpages-mapped kernel pagetables"
- depends on DEBUG_KERNEL && EXPERIMENTAL && X86_64
- help
- Enable gigabyte pages support (if the CPU supports it). This can
- improve the kernel's performance a tiny bit by reducing TLB
- pressure.
-
- This is experimental code.
-
- If in doubt, say "N".
-
config DEBUG_RODATA_TEST
bool "Testcase for the DEBUG_RODATA feature"
depends on DEBUG_RODATA
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