From 10971ab269bbf22120edac95fcfa3c873a549bea Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Thu, 5 Mar 2015 08:18:23 +0100 Subject: [PATCH] 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 Cc: Andrew Morton Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Borislav Petkov Cc: Dave Hansen Cc: David Vrabel Cc: Dexuan Cui Cc: Greg Kroah-Hartman Cc: H. Peter Anvin Cc: JBeulich@suse.com Cc: Jan Beulich Cc: Joonsoo Kim Cc: Juergen Gross Cc: Linus Torvalds Cc: Pavel Machek Cc: Thomas Gleixner Cc: Tony Lindgren Cc: Toshi Kani Cc: Vlastimil Babka Cc: Xishi Qiu Cc: julia.lawall@lip6.fr Signed-off-by: Ingo Molnar --- arch/x86/Kconfig | 20 ++++++-------------- arch/x86/mm/init.c | 7 +------ 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; -- 2.11.0