From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:38629) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1V1pHe-0000oo-Q3 for qemu-devel@nongnu.org; Tue, 23 Jul 2013 22:58:35 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1V1pHd-0005Og-Iu for qemu-devel@nongnu.org; Tue, 23 Jul 2013 22:58:34 -0400 Received: from mail-ob0-f182.google.com ([209.85.214.182]:53885) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1V1pHd-0005OR-ES for qemu-devel@nongnu.org; Tue, 23 Jul 2013 22:58:33 -0400 Received: by mail-ob0-f182.google.com with SMTP id va7so12045147obc.27 for ; Tue, 23 Jul 2013 19:58:32 -0700 (PDT) Message-ID: <51EF42CE.9030501@ozlabs.ru> Date: Wed, 24 Jul 2013 12:58:22 +1000 From: Alexey Kardashevskiy MIME-Version: 1.0 References: <1374506897-41089-1-git-send-email-agraf@suse.de> In-Reply-To: <1374506897-41089-1-git-send-email-agraf@suse.de> Content-Type: text/plain; charset=KOI8-R Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH] PPC: E500: Generate device tree on reset List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alexander Graf Cc: Scott Wood , "qemu-ppc@nongnu.org list:PowerPC" , qemu-devel Developers On 07/23/2013 01:28 AM, Alexander Graf wrote: > Today we generate the device tree once on machine initialization and then > store the finalized blob in memory to reload it on reset. > > This is bad for 2 reasons. First we potentially waste a bunch of RAM for no > good reason, as we have all information required to regenerate the device > tree available anyways. > > The second reason is even more important. On machine init when we generate > the device tree for the first time, we don't have all of the devices fully > initialized yet. But the device tree needs to potentially walk devices to > put information about them into the device tree. Not fully initialized yet? They are not even created at the machine init point as far as I can tell, and that was the reason to do for spapr what you are trying to do for e500 :) -- Alexey