From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:44799) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UKxuH-0003Tt-Tl for qemu-devel@nongnu.org; Wed, 27 Mar 2013 17:29:20 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UKxuC-00070u-OD for qemu-devel@nongnu.org; Wed, 27 Mar 2013 17:29:17 -0400 Received: from mx1.redhat.com ([209.132.183.28]:52278) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UKxuC-00070q-D9 for qemu-devel@nongnu.org; Wed, 27 Mar 2013 17:29:12 -0400 Message-ID: <51536452.6060701@redhat.com> Date: Wed, 27 Mar 2013 15:27:46 -0600 From: Eric Blake MIME-Version: 1.0 References: <1363963683-26157-1-git-send-email-owasserm@redhat.com> In-Reply-To: <1363963683-26157-1-git-send-email-owasserm@redhat.com> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="----enig2MQBKIAHFAAKENOQQVUQK" Subject: Re: [Qemu-devel] [PATCH v5 0/7] Migration: Remove copying of guest ram pages List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Orit Wasserman Cc: pbonzini@redhat.com, mst@redhat.com, chegu_vinod@hp.com, qemu-devel@nongnu.org, quintela@redhat.com This is an OpenPGP/MIME signed message (RFC 4880 and 3156) ------enig2MQBKIAHFAAKENOQQVUQK Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On 03/22/2013 08:47 AM, Orit Wasserman wrote: > In migration all data is copied to a static buffer in QEMUFile, > this hurts our network bandwidth and CPU usage especially with large gu= ests. > We switched to iovec for storing different buffers to send (even a byte= field is > considered as a buffer) and use sendmsg to send the iovec. > Adjacent iovecs are coalesced to create a bigger buffer instead of many= small > buffers. > =20 > Guest memory pages are not copied by calling a new function > qemu_put_buffer_async. > The page header data and device state data are still copied into the st= atic > buffer. This data consists of a lot of bytes and integer fields and the= static > buffer is used to store it during batching. >=20 > git repository: git://github.com/oritwas/qemu.git sendv_v2 >=20 > Changes from v4: > return ssize_t for writev_buffer ops. > Fix other Eric's comments. > Squash patch 8 (coalesce adjacent iovecs) into patch 4. Series: Reviewed-by: Eric Blake --=20 Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org ------enig2MQBKIAHFAAKENOQQVUQK 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/ iQEcBAEBCAAGBQJRU2RSAAoJEKeha0olJ0Nq6fAIAJMDsgr/0MOQmyS62DOXpjEZ IjUktKWNMQHc4lQ4ckNWL9tVhaz2xte/EWQ6qZfj7HWSHKE4/VcjE92TJBBclYan Z6J6Onldaxms32FyjjDKqs637nzpox+LUPCxK4DzITSlKSHuhkWVxmuwNHjRNyVE bunFBP6klPvqYGwA1oaRftaaxckXVz3GtRg8zzMXoYxgJIn0VTjf6psRCIu3aZjL iKAgLuEMzUL3oxYfaI7WqBW8GJBGi5gU/eaow6m8dDrGxYXamotYczAR+zlvksJz E0UL5yKTbc3VTq3eR86MqzkU+0Nch5BclckQ0n2J1jZClDQniWTt82ndumrQtcA= =I1y5 -----END PGP SIGNATURE----- ------enig2MQBKIAHFAAKENOQQVUQK--