From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751442AbbCEIF4 (ORCPT ); Thu, 5 Mar 2015 03:05:56 -0500 Received: from mail.emea.novell.com ([130.57.118.101]:51396 "EHLO mail.emea.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750738AbbCEIFy convert rfc822-to-8bit (ORCPT ); Thu, 5 Mar 2015 03:05:54 -0500 Message-Id: <54F81C6D0200007800066757@mail.emea.novell.com> X-Mailer: Novell GroupWise Internet Agent 14.0.1 Date: Thu, 05 Mar 2015 08:05:49 +0000 From: "Jan Beulich" To: "Ingo Molnar" Cc: , , , "Luis R. Rodriguez" , , , , , , , , , , , , "Juergen Gross" , "Luis Rodriguez" , , , , , Subject: Re: [PATCH 5/4] x86/mm: Further simplify 1 GB kernel linear mappings handling References: <1425518654-3403-1-git-send-email-mcgrof@do-not-panic.com> <20150305072313.GA23951@gmail.com> In-Reply-To: <20150305072313.GA23951@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 8BIT Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org >>> On 05.03.15 at 08:23, 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 > 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 | 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