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authorIngo Molnar <mingo@kernel.org>2015-03-05 08:18:23 +0100
committerIngo Molnar <mingo@kernel.org>2015-03-05 09:23:04 +0100
commit10971ab269bbf22120edac95fcfa3c873a549bea (patch)
tree69f51aa9d24bc66e9d4c2f0e9d586636d1f86404 /arch
parent73c8c861dc5bddf1b24c6aeffee2292c96cf8db2 (diff)
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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>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/Kconfig20
-rw-r--r--arch/x86/mm/init.c7
2 files changed, 7 insertions, 20 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 4d06e1c8294a..d03847513b6d 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1299,22 +1299,14 @@ config ARCH_DMA_ADDR_T_64BIT
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.
+ ---help---
+ 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
diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
index c35ba8bce7cb..8704153f2675 100644
--- a/arch/x86/mm/init.c
+++ b/arch/x86/mm/init.c
@@ -133,15 +133,10 @@ int after_bootmem;
static int page_size_mask;
-early_param_on_off("gbpages", "nogbpages",
- direct_gbpages, CONFIG_DIRECT_GBPAGES);
+early_param_on_off("gbpages", "nogbpages", direct_gbpages, CONFIG_X86_DIRECT_GBPAGES);
static void __init init_gbpages(void)
{
- if (!IS_ENABLED(CONFIG_ENABLE_DIRECT_GBPAGES)) {
- direct_gbpages = 0;
- return;
- }
if (direct_gbpages && cpu_has_gbpages) {
printk(KERN_INFO "Using GB pages for direct mapping\n");
page_size_mask |= 1 << PG_LEVEL_1G;