From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rusty Russell Subject: Re: [PATCH] i386: modified CONFIG_PHYSICAL_ALIGN Date: Tue, 14 Aug 2007 13:17:28 +1000 Message-ID: <1187061448.11093.63.camel@localhost.localdomain> References: <5AC7DE0DDBA7B1ichiyanagi.yoshimi@lab.ntt.co.jp> <20070814032903.GB3903@bingen.suse.de> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20070814032903.GB3903@bingen.suse.de> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org To: Andi Kleen Cc: zippel@linux-m68k.org, moriai.satoshi@lab.ntt.co.jp, Yoshimi Ichiyanagi , virtualization@lists.linux-foundation.org List-Id: virtualization@lists.linuxfoundation.org On Tue, 2007-08-14 at 05:29 +0200, Andi Kleen wrote: > On Tue, Aug 14, 2007 at 09:55:50AM +0900, Yoshimi Ichiyanagi wrote: > > How is this related to virtualization? > > > The problem is, if you compile x86_64 kernel, the value of > > CONFIG_PHYSICAL_ALIGN will be fixed, and the next time you compile i386 > > kernel, previous CONFIG_PHYSICAL_ALIGN value of x86_64(default: 2MB) will > > be used by default. > > 2/4MB is better for i386 too for PAE/non PAE because > it will use less TLB entries. I guess it's better to just change > the defaults. > > Anyways, both values should work, or did you see > failures? I had this problem too: Lguest assumes 1MB when loading bzImages, and the only time that gets changed is when building from an x86-64 config. I considered it purely an lguest issue. The correct fix is to have lguest run bzImages rather than trying to unpack them itself, but that requires a bootloader change, and the proposals to do that got lost in a flurry of far more ambitious patches. Jeremy would know the status of that work... Rusty.