From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:37631) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QuQrL-0005xY-EB for qemu-devel@nongnu.org; Fri, 19 Aug 2011 11:19:48 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1QuQrK-0002RH-7S for qemu-devel@nongnu.org; Fri, 19 Aug 2011 11:19:47 -0400 Received: from mx1.redhat.com ([209.132.183.28]:64460) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QuQrJ-0002Qr-S3 for qemu-devel@nongnu.org; Fri, 19 Aug 2011 11:19:46 -0400 Message-ID: <4E4E7F07.4040507@redhat.com> Date: Fri, 19 Aug 2011 08:19:35 -0700 From: Avi Kivity MIME-Version: 1.0 References: <4da1c5e91e8f61b6c17aa0756006d030013bedd8.1313620857.git.jan.kiszka@web.de> <4E4C50F6.20208@redhat.com> <4E4C5331.3070209@redhat.com> <4E4D9190.5090309@web.de> In-Reply-To: <4E4D9190.5090309@web.de> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v2 5/6] vga: Use linear mapping + dirty logging in chain 4 memory access mode List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jan Kiszka Cc: Anthony Liguori , qemu-devel , Gerd Hoffmann On 08/18/2011 03:26 PM, Jan Kiszka wrote: > On 2011-08-17 16:48, Avi Kivity wrote: > > On 08/17/2011 04:38 PM, Avi Kivity wrote: > >> > >> The mmio code has > >> > >> s->plane_updated |= mask; /* only used to detect font > >> change */ > >> > >> aren't we losing it? we could easily recover it via dirty logging. > >> > > Yes, I forgot to forward-port plane_updated = 0xf from v1 of the patch. > > > > > We can't really recover it. > > I don't see yet why we should not if we simply enforce a full update. > Can you elaborate? If we go for a full update we might as well disable dirty logging entirely. > > > So I think we need to restrict the > > optimization to graphic mode. > > > > Is grub using text mode or graphic mode? > > > > If it's using text mode, it may be faster to compare the font plane to a > > snapshot from the last redraw than to take an exit. > > I wasn't optimizing for text mode here, it's just a side effect if it > happens to benefit from it as well. I could exclude it, but only if > really needed. > Ok, so grub is using graphic mode? We'll need to force full updates in text mode then. -- I have a truly marvellous patch that fixes the bug which this signature is too narrow to contain.