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Commit 10971ab2 authored by Ingo Molnar's avatar Ingo Molnar
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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: default avatarIngo Molnar <mingo@kernel.org>
parent 73c8c861

arch/x86/Kconfig

+6 −14
Original line number Diff line number Diff line
@@ -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

arch/x86/mm/init.c

+1 −6
Original line number Diff line number Diff line
@@ -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;