From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:51037) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1S7o7a-0001aY-R5 for qemu-devel@nongnu.org; Wed, 14 Mar 2012 09:20:33 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1S7o7C-000479-AV for qemu-devel@nongnu.org; Wed, 14 Mar 2012 09:20:06 -0400 Received: from mx1.redhat.com ([209.132.183.28]:36734) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1S7o7C-00046x-2w for qemu-devel@nongnu.org; Wed, 14 Mar 2012 09:19:42 -0400 Date: Wed, 14 Mar 2012 15:19:32 +0200 From: Alon Levy Message-ID: <20120314131932.GH27659@garlic.redhat.com> References: <00c1eea5-ccb2-4b54-89f8-bdbf00fdc8a4@zmail17.collab.prod.int.phx2.redhat.com> <4F5F48F9.7090501@redhat.com> <4F606A09.2080906@redhat.com> <20120314101319.1a617a74@doriath.home> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <20120314101319.1a617a74@doriath.home> Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH/RFC 0/7] Screendump to UNIX socket & in PNG format List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Luiz Capitulino Cc: Stefan Hajnoczi , qemu-devel@nongnu.org, =?iso-8859-1?Q?Marc-Andr=E9?= Lureau , Gerd Hoffmann , =?iso-8859-1?Q?Marc-Andr=E9?= Lureau , =?iso-8859-1?Q?Marc-Andr=E9?= Lureau On Wed, Mar 14, 2012 at 10:13:19AM -0300, Luiz Capitulino wrote: > On Wed, 14 Mar 2012 10:01:15 +0000 > Stefan Hajnoczi wrote: >=20 > > On Wed, Mar 14, 2012 at 9:51 AM, Gerd Hoffmann wr= ote: > > > =A0Hi, > > > > > >> The most practical first step would be simply sending the ppm over= a > > >> socket from ppm_save(). =A0The 'screendump' command today already = blocks > > >> so no new badness is being added. =A0There would be no threads or = fancy > > >> image encoding. > > > > > > Adding scaling / compression support will add more overhead though,= so > > > doing that without offloading screendump to a thread first is a bad= idea > > > I think. =A0Or at least have some numbers to see how bad it actuall= y is. > >=20 > > I agree, that's why I suggest sending the ppm over a socket. It > > transports out the image data and QEMU itself doesn't do the > > encoding/scaling. >=20 > Just out of curiosity, are we planning to extend the current screendump > command or add a new one? >=20 > If we just extend the current command, then we'll have to make the > "filename" parameter optional. But this is a compatible change, I think. >=20 > Also, when returning the image via fd, we could offload its writing to > a bh. This would give us a poor man's async support, where the biggest > drawback would the lack of error detection (can this operation fail any= way?). >=20 It leaves detection of completion up to the user, so inotify / parsing the file to see if it's complete (header says size X, but file is still Y