From: Yoshiaki Tamura Subject: Re: Design document of Kemari Date: Sat, 07 Mar 2009 02:26:06 +0900 Message-ID: <49B15CAE.3050701@lab.ntt.co.jp> References: <49B073C5.6080702@lab.ntt.co.jp> <20090306162849.GA31979@movementarian.org> <49B153D6.6080100@lab.ntt.co.jp> <20090306170253.GB31979@movementarian.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20090306170253.GB31979@movementarian.org> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: John Levon Cc: xen-devel , Keir Fraser List-Id: xen-devel@lists.xenproject.org John Levon wrote: > On Sat, Mar 07, 2009 at 01:48:22AM +0900, Yoshiaki Tamura wrote: > >> I believe Kemari and Remus shares a lot in common. >> Stephen and Ian have described both Kemari and Remus on the roadmap >> document, and that might help for quick review. >> >> http://blog.xen.org/index.php/2008/12/08/xen-roadmap-document-2/ >> >> In short, Kemari transfers the guest VM on event-driven, while Remus >> transfers on specific interval. > > Thanks. Do you have performance numbers? It sounds like your approach is > intended to give lower I/O response latencies, but Remus will give > better throughput with high I/O load as it doesn't sync on every single > outgoing I/O. Thanks for your interest. Although the numbers are old, you can get an extended abstract and slides which I used at Xen Summit from http://www.osrg.net/kemari The patchset I sent today seems to perform a lot better, but I don't have papers yet. Regarding the throughput, possible idea is to buffer some events to reduce the frequency, which would introduce latencies as a trade off. Although we haven't implemented this feature yet, it may be interesting how the numbers change. > If both projects are indeed headed for the tree, people are going to > need some ideas of which to use... Well, I sent the following message when I open-sourced Kemari in November. http://lists.xensource.com/archives/html/xen-devel/2008-11/msg00682.html Thanks, Yoshi