From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:37383) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QqR21-0001zb-Vw for qemu-devel@nongnu.org; Mon, 08 Aug 2011 10:42:19 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1QqR20-0003OM-Tj for qemu-devel@nongnu.org; Mon, 08 Aug 2011 10:42:17 -0400 Received: from mx1.redhat.com ([209.132.183.28]:61936) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QqR20-0003O7-MX for qemu-devel@nongnu.org; Mon, 08 Aug 2011 10:42:16 -0400 Message-ID: <4E3FF5BD.4080008@redhat.com> Date: Mon, 08 Aug 2011 17:42:05 +0300 From: Avi Kivity MIME-Version: 1.0 References: <4E3FE4CF.4060108@codemonkey.ws> <20110808140444.GB5699@redhat.com> In-Reply-To: <20110808140444.GB5699@redhat.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [libvirt] [PATCH v4] XBZRLE delta for live migration of large memory apps List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Daniel P. Berrange" Cc: Dor Laor , qemu-devel Developers , libvirt-list@redhat.com, Blue Swirl , "Shribman, Aidan" On 08/08/2011 05:04 PM, Daniel P. Berrange wrote: > My main concern with all these scenarios where libvirt touches the > actual data stream though is that we're introducing extra data copies > into the migration path which potentially waste CPU cycles. > If QEMU can directly XBZRLE encode data into the FD passed via 'fd:' > then we minimize data copies. Whether this is a big enough benefit > to offset the burden of having to maintain various compression code > options in QEMU I can't answer. > It's counterproductive to force an unneeded data copy in order to increase bandwidth. -- error compiling committee.c: too many arguments to function