Messages in this thread | | | Date | Thu, 05 Mar 2015 08:05:49 +0000 | From | "Jan Beulich" <> | Subject | Re: [PATCH 5/4] x86/mm: Further simplify 1 GB kernel linear mappings handling |
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>>> On 05.03.15 at 08:23, <mingo@kernel.org> wrote:
> 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> > --- > arch/x86/Kconfig | 23 +++++++---------------- > arch/x86/mm/init.c | 7 +------ > 2 files changed, 8 insertions(+), 22 deletions(-) > > diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig > index 4d06e1c8294a..54d528a37ff4 100644 > --- a/arch/x86/Kconfig > +++ b/arch/x86/Kconfig > @@ -1299,22 +1299,13 @@ config ARCH_DMA_ADDR_T_64BIT > def_bool y > depends on X86_64 || HIGHMEM64G > > -config ENABLE_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. > +config X86_DIRECT_GBPAGES > + def_bool (X86_64 && !DEBUG_PAGEALLOC && !KMEMCHECK)
config X86_DIRECT_GBPAGES def_bool y depends on X86_64 && !DEBUG_PAGEALLOC && !KMEMCHECK
or else it'll leave a pointless
# CONFIG_X86_DIRECT_GBPAGES is not set
in .config-s where the dependencies are not met.
Jan
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