From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e23smtp01.au.ibm.com (E23SMTP01.au.ibm.com [202.81.18.162]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "e23smtp01.au.ibm.com", Issuer "Equifax" (verified OK)) by ozlabs.org (Postfix) with ESMTPS id 6CE35DDDE7 for ; Wed, 12 Nov 2008 10:22:38 +1100 (EST) Received: from sd0109e.au.ibm.com (d23rh905.au.ibm.com [202.81.18.225]) by e23smtp01.au.ibm.com (8.13.1/8.13.1) with ESMTP id mABNMRon030396 for ; Wed, 12 Nov 2008 10:22:27 +1100 Received: from d23av01.au.ibm.com (d23av01.au.ibm.com [9.190.234.96]) by sd0109e.au.ibm.com (8.13.8/8.13.8/NCO v9.1) with ESMTP id mABNMOgB207972 for ; Wed, 12 Nov 2008 10:22:24 +1100 Received: from d23av01.au.ibm.com (loopback [127.0.0.1]) by d23av01.au.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id mABNMOR4002830 for ; Wed, 12 Nov 2008 10:22:24 +1100 Date: Wed, 12 Nov 2008 10:20:06 +1100 From: David Gibson To: Josh Boyer Subject: Re: [PATCH] [v2] powerpc/4xx: work around CHIP11 errata in a more PAGE_SIZE-friendly way Message-ID: <20081111232006.GA17193@yookeroo.seuss> References: <20081111125218.GA2266@yoda.jdub.homelinux.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20081111125218.GA2266@yoda.jdub.homelinux.org> Cc: kvm-ppc@vger.kernel.org, linuxppc-dev@ozlabs.org, yanok@emcraft.com, Hollis Blanchard List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Tue, Nov 11, 2008 at 07:52:18AM -0500, Josh Boyer wrote: > On Mon, Nov 10, 2008 at 05:24:34PM -0600, Hollis Blanchard wrote: > >The current CHIP11 errata truncates the device tree memory node, and subtracts > >(hardcoded) 4096 bytes. This breaks kernels with larger PAGE_SIZE, since the > >bootmem allocator assumes that total memory is a multiple of PAGE_SIZE. > > > >Instead, use a device tree memory reservation to reserve only the 256 bytes > >actually affected by the errata, leaving the total memory size unaltered. > > > >Signed-off-by: Hollis Blanchard > > > >--- > > > >Using large pages results in a huge performance improvement for KVM, and this > >patch is required to make Ilya's large page patch work. David and/or Josh, > >please apply. > > The patch looks fine to me, and once David acks the fdt parts I'll apply > for -next. I'll try to do some testing later today as well, since I have > one of the boards with the Errata. Um.. I sent something the fdt stuff a while back, but didn't get a response. -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson