From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755113AbYJVKf1 (ORCPT ); Wed, 22 Oct 2008 06:35:27 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753269AbYJVKfO (ORCPT ); Wed, 22 Oct 2008 06:35:14 -0400 Received: from ns.suse.de ([195.135.220.2]:41422 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753092AbYJVKfN (ORCPT ); Wed, 22 Oct 2008 06:35:13 -0400 Date: Wed, 22 Oct 2008 12:35:12 +0200 From: Nick Piggin To: Andrew Morton , Andi Kleen Cc: Linux Kernel Mailing List , Ingo Molnar Subject: Re: [patch] x86: enable GBPAGES option by default Message-ID: <20081022103512.GA1928@wotan.suse.de> References: <20081022103316.GB27862@wotan.suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20081022103316.GB27862@wotan.suse.de> User-Agent: Mutt/1.5.9i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Oops, messed up Andi's email... On Wed, Oct 22, 2008 at 12:33:16PM +0200, Nick Piggin wrote: > DIRECT_GBPAGES was under DEBUG_KERNEL && EXPERIMENTAL and disabled by default. > Turn it on by default and put it under EMBEDDED. > > Signed-off-by: Nick Piggin > --- > Index: linux-2.6/arch/x86/Kconfig > =================================================================== > --- linux-2.6.orig/arch/x86/Kconfig > +++ linux-2.6/arch/x86/Kconfig > @@ -946,6 +946,15 @@ config X86_PAE > config ARCH_PHYS_ADDR_T_64BIT > def_bool X86_64 || X86_PAE > > +config DIRECT_GBPAGES > + bool "Enable 1GB pages for kernel pagetables" if EMBEDDED > + default y > + depends on X86_64 > + help > + Allow 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". > + > # Common NUMA Features > config NUMA > bool "Numa Memory Allocation and Scheduler Support (EXPERIMENTAL)" > Index: linux-2.6/arch/x86/Kconfig.debug > =================================================================== > --- linux-2.6.orig/arch/x86/Kconfig.debug > +++ linux-2.6/arch/x86/Kconfig.debug > @@ -114,18 +114,6 @@ config DEBUG_RODATA > data. This is recommended so that we can catch kernel bugs sooner. > If in doubt, say "Y". > > -config DIRECT_GBPAGES > - bool "Enable gbpages-mapped kernel pagetables" > - depends on DEBUG_KERNEL && EXPERIMENTAL && X86_64 > - help > - Enable gigabyte pages support (if the CPU supports it). This can > - improve the kernel's performance a tiny bit by reducing TLB > - pressure. > - > - This is experimental code. > - > - If in doubt, say "N". > - > config DEBUG_RODATA_TEST > bool "Testcase for the DEBUG_RODATA feature" > depends on DEBUG_RODATA