From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:34443) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QuWah-0007OJ-UC for qemu-devel@nongnu.org; Fri, 19 Aug 2011 17:27:00 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1QuWag-0004XD-Qg for qemu-devel@nongnu.org; Fri, 19 Aug 2011 17:26:59 -0400 Received: from fmmailgate03.web.de ([217.72.192.234]:36816) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QuWag-0004WC-EI for qemu-devel@nongnu.org; Fri, 19 Aug 2011 17:26:58 -0400 Message-ID: <4E4ED519.3040704@web.de> Date: Fri, 19 Aug 2011 14:26:49 -0700 From: Jan Kiszka MIME-Version: 1.0 References: <4da1c5e91e8f61b6c17aa0756006d030013bedd8.1313620857.git.jan.kiszka@web.de> <4E4C50F6.20208@redhat.com> <4E4C5331.3070209@redhat.com> <4E4D9190.5090309@web.de> <4E4E7F07.4040507@redhat.com> In-Reply-To: <4E4E7F07.4040507@redhat.com> Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig4E1903C66012DC2ADE89321E" Sender: jan.kiszka@web.de 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: Avi Kivity Cc: Anthony Liguori , qemu-devel , Gerd Hoffmann This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig4E1903C66012DC2ADE89321E Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable On 2011-08-19 08:19, Avi Kivity wrote: > 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 |=3D mask; /* only used to detect fon= t >> >> change */ >> >> >> >> aren't we losing it? we could easily recover it via dirty logging= =2E >> >> >> >> Yes, I forgot to forward-port plane_updated =3D 0xf from v1 of the pat= ch. >> >> > >> > 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? >=20 > If we go for a full update we might as well disable dirty logging entir= ely. Full update only affects text screen refreshes. The guest access to the VRAM will still benefit from the much faster mmio. >=20 >> >> > 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. >> >=20 > Ok, so grub is using graphic mode? Yep. >=20 >=20 > We'll need to force full updates in text mode then. Right. I'll sent an update doing that. There are some other quirks of the series remaining I'm addressing ATM. Jan --------------enig4E1903C66012DC2ADE89321E Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.16 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAk5O1RwACgkQitSsb3rl5xQG0ACgmXCJzKpzVpcd5WGV0ZiAVkmR bfkAnioNCZ5WUCIOo6gZPVErK93rJJ20 =iH3N -----END PGP SIGNATURE----- --------------enig4E1903C66012DC2ADE89321E--