From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:34746) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UFRgI-00026J-If for qemu-devel@nongnu.org; Tue, 12 Mar 2013 12:04:08 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UFRg8-00087d-Hg for qemu-devel@nongnu.org; Tue, 12 Mar 2013 12:04:02 -0400 Received: from mx1.redhat.com ([209.132.183.28]:61734) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UFRg8-00085A-9H for qemu-devel@nongnu.org; Tue, 12 Mar 2013 12:03:52 -0400 Message-ID: <513F51E2.4030007@redhat.com> Date: Tue, 12 Mar 2013 10:03:46 -0600 From: Eric Blake MIME-Version: 1.0 References: <513F4F1E.2060400@dlhnet.de> In-Reply-To: <513F4F1E.2060400@dlhnet.de> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="----enig2XOGRTGKKOHWJGGQRARMK" Subject: Re: [Qemu-devel] [RFC][PATCH 6/9] migration: use XBZRLE only after bulk stage List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Lieven Cc: Kevin Wolf , Paolo Bonzini , Stefan Hajnoczi , "qemu-devel@nongnu.org" , Orit Wasserman This is an OpenPGP/MIME signed message (RFC 4880 and 3156) ------enig2XOGRTGKKOHWJGGQRARMK Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On 03/12/2013 09:51 AM, Peter Lieven wrote: > at the beginning of migration all pages are marked dirty and > in the first round a bulk migration of all pages is performed. >=20 > currently all these pages are copied to the page cache regardless > if there are frequently updated or not. this doesn't make sense > since most of these pages are never transferred again. >=20 > this patch changes the XBZRLE transfer to only be used after > the bulk stage has been completed. that means a page is added > to the page cache the second time it is transferred and XBZRLE > can benefit from the third time of transfer. >=20 > since the page cache is likely smaller than the number of pages > its also likely that in the second round the page is missing in the > cache due to collisions in the bulk phase. >=20 > on the other hand a lot of unneccssary mallocs, memdups and frees s/unneccssary/unnecessary/ > are saved. Earlier, I asked you for some benchmark numbers, and you provided some. Mentioning them in the commit message will make an even stronger argument for including this patch. --=20 Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org ------enig2XOGRTGKKOHWJGGQRARMK Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.13 (GNU/Linux) Comment: Public key at http://people.redhat.com/eblake/eblake.gpg Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQEcBAEBCAAGBQJRP1HiAAoJEKeha0olJ0NqR2kH/Rq++xzo+vZblW0duTDsnOJ0 SLtarmSZTW9qWcGQslDcTsj/r1aqnwoRofitpoDrCibjHKi104c9a6cPy+GZitJM LnH4usPwb38CCz0fFKlPinFva5OvUAjjI4JzmAnQ/bGm6f3qs65XSYPjTsToWKHF V6WuCVW1a8q4fZVPTH6r+H9teb1xGynejfW2JHh1neODJxjVpbKUqs0EQgp309+o 5W5DIy7/HcWsKimbld6dA2JAu0rG1D3YsS930CheXWCF+pSU5qaZNhJYJAOijPFt 1wByGLVWwvLuaNm41u+Hon1BwdkvpdhxeEEZNFR1mopW/QBX57NGbaOKtA1kR4c= =HAqp -----END PGP SIGNATURE----- ------enig2XOGRTGKKOHWJGGQRARMK--