x86/mm: Further simplify 1 GB kernel linear mappings handling
It's a bit pointless to allow Kconfig configuration for 1GB kernel
mappings, it's already hidden behind a 'default y' and CONFIG_EXPERT.
Remove this complication and simplify the code by renaming
CONFIG_ENABLE_DIRECT_GBPAGES to CONFIG_X86_DIRECT_GBPAGES and
document the DEBUG_PAGE_ALLOC and KMEMCHECK quirks.
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Dexuan Cui <decui@microsoft.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: JBeulich@suse.com
Cc: Jan Beulich <JBeulich@suse.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: julia.lawall@lip6.fr
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 4d06e1c..d038475 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1299,22 +1299,14 @@
def_bool y
depends on X86_64 || HIGHMEM64G
-config ENABLE_DIRECT_GBPAGES
+config X86_DIRECT_GBPAGES
def_bool y
depends on X86_64 && !DEBUG_PAGEALLOC && !KMEMCHECK
-
-config DIRECT_GBPAGES
- bool "Enable 1GB pages for kernel pagetables" if EXPERT
- default y
- depends on ENABLE_DIRECT_GBPAGES
---help---
- Enable by default 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". If you've disabled
- option but your platform is capable of handling support for this
- you can use the gbpages kernel parameter. Likewise if you've enabled
- this but you'd like to force disable this option you can use the
- nogbpages kernel parameter.
+ Certain kernel features effectively disable kernel
+ linear 1 GB mappings (even if the CPU otherwise
+ supports them), so don't confuse the user by printing
+ that we have them enabled.
# Common NUMA Features
config NUMA