From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:34194) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UK8y5-0008NT-Iq for qemu-devel@nongnu.org; Mon, 25 Mar 2013 11:05:55 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UK8xz-0002aS-Ix for qemu-devel@nongnu.org; Mon, 25 Mar 2013 11:05:49 -0400 Received: from mx1.redhat.com ([209.132.183.28]:48575) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UK8xz-0002aE-6W for qemu-devel@nongnu.org; Mon, 25 Mar 2013 11:05:43 -0400 Message-ID: <515067BB.5060600@redhat.com> Date: Mon, 25 Mar 2013 09:05:31 -0600 From: Eric Blake MIME-Version: 1.0 References: <20130320081130.GA5953@stefanha-thinkpad.muc.redhat.com> <514A4104.9000505@redhat.com> In-Reply-To: Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="----enig2DBWPMAGEAGIBSTXRDJOK" Subject: Re: [Qemu-devel] kvm suspend performance List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Thomas Knauth Cc: Stefan Hajnoczi , qemu-devel@nongnu.org This is an OpenPGP/MIME signed message (RFC 4880 and 3156) ------enig2DBWPMAGEAGIBSTXRDJOK Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On 03/23/2013 06:42 AM, Thomas Knauth wrote: > Hi Eric, >=20 > thanks for the reply. This indeed solved my issue. Suspending is much > faster without the artificial throttle. >=20 > On a related note: I'm curious about the baseline resume latency. It ta= kes > about 5 seconds to resume an instance with a tiny amount of state (500 = MB > dump size). The data is all in the page cache. I measure the time it ta= kes > the 'virsh restore ' command to return. >=20 > Any opinions on what could be the issue here? I've also linked to a fig= ure > illustrating the problem. Resume speed scales nicely with increased dum= p > size, but the baseline penalty feels awfully high Sorry, but I haven't ever profiled it to see where the problems might lie. It sounds like it might be an interesting project if you want to take it on, but I don't have the time to spend on it myself at the moment= =2E --=20 Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org ------enig2DBWPMAGEAGIBSTXRDJOK 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/ iQEcBAEBCAAGBQJRUGe8AAoJEKeha0olJ0Nq9Y8IAJsyQMiGddrm9ZSDqCmY+b+E wUx91gXlpBhJcMLywvBr6dIK0qLkp4pJiP6kAjQeE//DUErjtEK3+SinK1FBszrV cb6GyrjA3jTrVcRgB99hyFkfNPsE+b7b5MHJP60JxZUmZf5Obak4+M0CfKC5sEr9 AWKx8Brd6PgFBeIcvhG+xumQsOCq7TuM0f9ELpEM+bYQGLodSFub/du6bgmLkO3m BX7L3gw6UShdIz6MixMvvz/2400qdHAUVaM9FZW0vCzLiWb6phUANsl7y+vHJFgG RfQi5+nY3akUn9xhjGMzkE37HgCMRZWeveKWLLPjRh63ugrnMTbhSECI6ETb3IA= =H1Me -----END PGP SIGNATURE----- ------enig2DBWPMAGEAGIBSTXRDJOK--