From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:60392) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XhIvn-0004sk-V7 for qemu-devel@nongnu.org; Thu, 23 Oct 2014 10:00:04 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XhIvi-0000fx-So for qemu-devel@nongnu.org; Thu, 23 Oct 2014 09:59:59 -0400 Received: from mx1.redhat.com ([209.132.183.28]:9164) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XhIvi-0000fo-KC for qemu-devel@nongnu.org; Thu, 23 Oct 2014 09:59:54 -0400 Received: from int-mx14.intmail.prod.int.phx2.redhat.com (int-mx14.intmail.prod.int.phx2.redhat.com [10.5.11.27]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id s9NDxGHh023839 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL) for ; Thu, 23 Oct 2014 09:59:53 -0400 Message-ID: <5448FE52.3050809@redhat.com> Date: Thu, 23 Oct 2014 07:10:42 -0600 From: Eric Blake MIME-Version: 1.0 References: <1413982283-10186-1-git-send-email-mreitz@redhat.com> <1413982283-10186-8-git-send-email-mreitz@redhat.com> <20141023105230.GJ3522@noname.redhat.com> In-Reply-To: <20141023105230.GJ3522@noname.redhat.com> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="1VHIV9xWffLgRcOxWdrdkr3KXFT8qHF1F" Subject: Re: [Qemu-devel] [PATCH v13 07/14] block/mirror: Improve progress report List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Kevin Wolf , Max Reitz Cc: qemu-devel@nongnu.org, Stefan Hajnoczi This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --1VHIV9xWffLgRcOxWdrdkr3KXFT8qHF1F Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On 10/23/2014 04:52 AM, Kevin Wolf wrote: > Am 22.10.2014 um 14:51 hat Max Reitz geschrieben: >> Instead of taking the total length of the block device as the block >> job's length, use the number of dirty sectors. The progress is now the= >> number of sectors mirrored to the target block device. Note that this >> may result in the job's length increasing during operation, which is >> however in fact desirable. >=20 > More importantly, because it might surprise management tools, is that > the progress (as in offset/len) can actually decrease now. Decreased progress is a GOOD thing - it tells management that the guest is causing I/O faster than the mirroring can keep up with, and that it might be time to turn on some throttling if the mirror is going to have a chance at converging. The old code didn't have any correlation to progress complete vs work remaining, making it harder to accurately estimate how long a job still has to go. >=20 > I can't say whether that creates any problem, I'll rely on Eric's > Reviewed-by for that. Libvirt has already documented that for all jobs (including block jobs), progress is estimated by offset/total, but that total need not be constant between two consecutive calls, precisely for the behavior that this patch moves toward. --=20 Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org --1VHIV9xWffLgRcOxWdrdkr3KXFT8qHF1F Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 Comment: Public key at http://people.redhat.com/eblake/eblake.gpg iQEcBAEBCAAGBQJUSP5SAAoJEKeha0olJ0NqoGAIAKfkrfwUKaaMlLCoU/wgCY64 PwDq4Mw2ECmYNS6v2ODwwwio9Oay433mu07Fb/CQmbwv+sXU31KImZ5ITNx4peJR AbhGqNFa4cp3Gd1fNqzcW2/ez/ducYlxJDndGpW8PDwy+wOLL9Fvzc4nbtEz4v/x mfjZ9/F14fkruSWLsXEE7FYolDCUqK4QpG4ouNVALAQiSfQbiQvUS5FDKTobDex2 ZeCJd340irglh4Nhp4FpDLGrMtO8NnQRxUQVDhPfM9FaYqkk7rkktsixk3+mP8MR FZPTAGBKQhWRICIHmCe4LDvrC/WGSPv40lvJxNLzjyoWsYTGJckmgiRHs7vFN7I= =To5R -----END PGP SIGNATURE----- --1VHIV9xWffLgRcOxWdrdkr3KXFT8qHF1F--