From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:60949) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1e2dzB-0002SO-El for qemu-devel@nongnu.org; Thu, 12 Oct 2017 09:57:18 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1e2dzA-0006to-IC for qemu-devel@nongnu.org; Thu, 12 Oct 2017 09:57:17 -0400 References: <20171002143919.207741-1-vsementsov@virtuozzo.com> <20171002143919.207741-5-vsementsov@virtuozzo.com> <2cb5ac95-e27c-2d13-b557-9dedc1f86473@virtuozzo.com> From: Eric Blake Message-ID: <28aa9488-8cf3-b71f-5c74-74c884fbe3be@redhat.com> Date: Thu, 12 Oct 2017 08:56:46 -0500 MIME-Version: 1.0 In-Reply-To: <2cb5ac95-e27c-2d13-b557-9dedc1f86473@virtuozzo.com> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="g1cXWD6SHw1jKVXjV6R2bDONkgUN63Tej" Subject: Re: [Qemu-devel] [PATCH 4/5] backup: simplify non-dirty bits progress processing List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Vladimir Sementsov-Ogievskiy , John Snow , qemu-block@nongnu.org, qemu-devel@nongnu.org Cc: kwolf@redhat.com, famz@redhat.com, jcody@redhat.com, mreitz@redhat.com, stefanha@redhat.com, den@openvz.org This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --g1cXWD6SHw1jKVXjV6R2bDONkgUN63Tej From: Eric Blake To: Vladimir Sementsov-Ogievskiy , John Snow , qemu-block@nongnu.org, qemu-devel@nongnu.org Cc: kwolf@redhat.com, famz@redhat.com, jcody@redhat.com, mreitz@redhat.com, stefanha@redhat.com, den@openvz.org Message-ID: <28aa9488-8cf3-b71f-5c74-74c884fbe3be@redhat.com> Subject: Re: [Qemu-devel] [PATCH 4/5] backup: simplify non-dirty bits progress processing References: <20171002143919.207741-1-vsementsov@virtuozzo.com> <20171002143919.207741-5-vsementsov@virtuozzo.com> <2cb5ac95-e27c-2d13-b557-9dedc1f86473@virtuozzo.com> In-Reply-To: <2cb5ac95-e27c-2d13-b557-9dedc1f86473@virtuozzo.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On 10/12/2017 06:42 AM, Vladimir Sementsov-Ogievskiy wrote: >> I'm not sure we actually need a new field... let's just say that the j= ob >> length is the number of bytes described by the incremental backup. Eve= ry >> time we copy some, move offset forward. This would give a more >> appropriately linear/accurate sense of the progress. >> >> I think we are allowed to do this as I think we promise that these >> progress numbers mean essentially nothing... >=20 > I'm not sure, length is published field, it is available in libvirt. > IMHO, If we change it semantics it should > firstly break our iotests but what it will break for users is > unpredictable.. Libvirt already documents that progress numbers do NOT have any specific meaning other than a rough estimate of percentage complete, and that it IS acceptable for the numbers to jump around or move non-linearly during a job. I see no problem with returning different numbers than previously if it makes our estimation of progress look smoother; it is not a semantics change by the definition we've given to the numbers, but merely a quality-of-implementation improvement. --=20 Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3266 Virtualization: qemu.org | libvirt.org --g1cXWD6SHw1jKVXjV6R2bDONkgUN63Tej Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Comment: Public key at http://people.redhat.com/eblake/eblake.gpg Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQEzBAEBCAAdFiEEccLMIrHEYCkn0vOqp6FrSiUnQ2oFAlnfdJ4ACgkQp6FrSiUn Q2rt7ggAocRL8DmLrq04dOXCcQ9voJlsH3I9g7VMxiJ3/FepTHBfvUI9qp4NuPfr Xzu0WjmoARYmH9hV5C0yV564du2Caj8V6MxMnjuR3+5rrKWL0oTgMtUMewhYCFu3 bEz6k8KAJhwpIm2EB7ZBy+C8zo5R687ZwMWGI9gb5fuyMGMg/GXxG0TGSlsleOYT HH93brBmZmVj95Z9hFUdmzhJTzPNpW+HsH8EulT9nAr8254mqkbMjBGBaeLLyIVL 3izui1qX0isC8tjE4K2GBrwbrvHA6WfaakW1/VSRwuGtGvL4opPaPcqMvugRZjeS PD/JQYyDN9ntHEKbSP5w4YcSY9oujw== =rITL -----END PGP SIGNATURE----- --g1cXWD6SHw1jKVXjV6R2bDONkgUN63Tej--