From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:33751) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1a1DyJ-0006Q5-At for qemu-devel@nongnu.org; Tue, 24 Nov 2015 08:49:28 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1a1DyG-0001Lv-4e for qemu-devel@nongnu.org; Tue, 24 Nov 2015 08:49:27 -0500 Received: from mx1.redhat.com ([209.132.183.28]:59719) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1a1DyF-0001Lr-T3 for qemu-devel@nongnu.org; Tue, 24 Nov 2015 08:49:24 -0500 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 (Postfix) with ESMTPS id 81415C1A1652 for ; Tue, 24 Nov 2015 13:49:23 +0000 (UTC) References: <1448273262-13845-1-git-send-email-peterx@redhat.com> <56533D45.1060108@redhat.com> <20151123175759.GG3606@hawk.localdomain> <5653C422.3040307@redhat.com> <20151124031027.GC26733@ad.usersys.redhat.com> <56544694.3060309@redhat.com> <20151124113723.GA29832@ad.usersys.redhat.com> From: Eric Blake Message-ID: <56546ADC.5050402@redhat.com> Date: Tue, 24 Nov 2015 06:49:16 -0700 MIME-Version: 1.0 In-Reply-To: <20151124113723.GA29832@ad.usersys.redhat.com> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="mlKTEafP94rTaUoQexSgqhJL03di3aDMm" Subject: Re: [Qemu-devel] [PATCH REPOST 0/2] Add basic "detach" support for dump-guest-memory List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Fam Zheng , Laszlo Ersek Cc: Andrew Jones , qemu-devel@nongnu.org, armbru@redhat.com, Peter Xu , lcapitulino@redhat.com, pbonzini@redhat.com This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --mlKTEafP94rTaUoQexSgqhJL03di3aDMm Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On 11/24/2015 04:37 AM, Fam Zheng wrote: >> I think the patch should be dropped, and periodic progress reports >> should be emitted from within the dump loops that do the heavy lifting= =2E >> >> For the ELF format dumps, that loop appears to reside in dump_iterate(= ) >> [dump.c]. >> >> For the compressed format dumps, the loop seems to live in >> write_dump_pages() [dump.c]. >=20 > This is a good idea! >=20 > What I'm not sure is where to report the progress. Can it be the monito= r where > the dump-guest-memory command was issued? In other words, do we support= raising > events before the previous command returns? If yes, can libvirt handle = this > correctly? (But the worst case is using another channel to communicate = the > progress, it is ad-hocery but it must be better than all the risk and e= ffort to > enable multi-threaded dump.) >=20 > Eric, Markus, have any idea with the progress reporting? I'm fairly certain we support raising events prior to completion of a synchronous command; what I'm not sure of is whether the event hits the wire right away or whether it piles up waiting for the next synchronous command completion. If the latter, then we need to rework it (since the whole point of this exercise is that we are trying to give progress of a long-running synchronous command that hasn't completed yet). But we only have the one monitor connection for libvirt - the only way to pass events through a second channel is to open a second monitor connection, but that feels wrong to make libvirt have to track two monitors. --=20 Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org --mlKTEafP94rTaUoQexSgqhJL03di3aDMm 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 Comment: Public key at http://people.redhat.com/eblake/eblake.gpg Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQEcBAEBCAAGBQJWVGrcAAoJEKeha0olJ0NqKUAIAIf1DNvMKwI6NfEvi+r7svP1 ihy7K9FTbySzRpcWyUpIIVzQvbK0JFaWwngKtTx0CIkLwO3VD6nA2R2kSPR1S4Tf p/MSDjm8qsK8c7Y8jYhEFvU8MHsU5OiedoxLKkgNDifpWwAG5E/8YAn9cF2TEBLQ oON1nhQBlvdYRlrfhj/vLimSU2s/lALUlQUTLAHCz0Lat4wwj5SrSBTPaKvx+THi NLALj0+mtj5v6xrnqJQ9uMtH0koAN8rnGCbXd6TxfAWkfmImTSVP6058wBNjtrhc HpQLMxH4i62hgYXNy7gZbM34l1hzy8X0LOpxx/bxNzzEL7kyCldJadaNqJykhEo= =nrig -----END PGP SIGNATURE----- --mlKTEafP94rTaUoQexSgqhJL03di3aDMm--