From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:44279) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aTRhI-0006u0-9u for qemu-devel@nongnu.org; Wed, 10 Feb 2016 05:08:33 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aTRhF-0005Er-1z for qemu-devel@nongnu.org; Wed, 10 Feb 2016 05:08:32 -0500 Received: from mail-wm0-x22c.google.com ([2a00:1450:400c:c09::22c]:36825) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aTRhE-0005Ek-Rz for qemu-devel@nongnu.org; Wed, 10 Feb 2016 05:08:29 -0500 Received: by mail-wm0-x22c.google.com with SMTP id p63so20661508wmp.1 for ; Wed, 10 Feb 2016 02:08:28 -0800 (PST) Date: Wed, 10 Feb 2016 10:08:25 +0000 From: Stefan Hajnoczi Message-ID: <20160210100825.GA7317@stefanha-x1.localdomain> References: <1454151394-52320-1-git-send-email-vsementsov@virtuozzo.com> <1454151394-52320-3-git-send-email-vsementsov@virtuozzo.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="G4iJoqBmSsgzjUCe" Content-Disposition: inline In-Reply-To: <1454151394-52320-3-git-send-email-vsementsov@virtuozzo.com> Subject: Re: [Qemu-devel] [PATCH 2/6] qmp: add query-block-dirty-bitmap-ranges List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Vladimir Sementsov-Ogievskiy Cc: kwolf@redhat.com, famz@redhat.com, den@virtuozzo.com, armbru@redhat.com, qemu-devel@nongnu.org, jsnow@redhat.com --G4iJoqBmSsgzjUCe Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Sat, Jan 30, 2016 at 01:56:30PM +0300, Vladimir Sementsov-Ogievskiy wrot= e: > Add qmp command to query dirty bitmap contents. This is needed for > external backup. >=20 > Signed-off-by: Vladimir Sementsov-Ogievskiy > --- > block/dirty-bitmap.c | 55 +++++++++++++++++++++++++++++++++++++++ > blockdev.c | 62 ++++++++++++++++++++++++++++++++++++++= ++++++ > include/block/dirty-bitmap.h | 7 +++++ > qapi/block-core.json | 54 ++++++++++++++++++++++++++++++++++++++ > qmp-commands.hx | 33 +++++++++++++++++++++++ > 5 files changed, 211 insertions(+) This API produces large replies and/or requires many calls to fetch all bitmap data. The worst case is a 101010... bitmap. I consider the dirty bitmap to be data (vs control) and not something that should be sent over a control channel like the QMP monitor. How about writing the dirty bitmap to a file? The new bitmap file format that Fam is working on could be used. That way the dirty bitmap can be saved asynchronously without hogging the QMP monitor. --G4iJoqBmSsgzjUCe Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQEcBAEBAgAGBQJWuwwZAAoJEJykq7OBq3PIE44H/24CIGoSS9eHzJR/T7fayAk2 OMyOAxenUkZP6tse/luinOVNy3sRj9dDfmu9t0XdZ7puh7Sls3E7o6TWZE0+MUGT jmkC/lPMUUFMjzjYhGPMav8dLVJREv7li8PTfemRAD9nIb7ncGIH16/WZspvlbRY yI49F1JDT63JrRpJYwM+lGI1Eq2cjCxvNi9t34lnU6OURqnn9XqUgpY5RJgQdcyj nzmgPLMEaZ7tW0dByFRJsVBFmp2ZoNeEiCC/xKK6GIuZQj81ukNBrJ1dfdh5EPZZ YJKF24dUMs3Q5gfloY9CbtoVxag/SSkjy3ZW+r2AFRQ+CpPf2iHomzZskaF+jUg= =VS+B -----END PGP SIGNATURE----- --G4iJoqBmSsgzjUCe--