From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rik van Riel Subject: Re: kvm & dyntick Date: Fri, 12 Jan 2007 00:34:34 -0500 Message-ID: <45A71DEA.9020307@redhat.com> References: <45A66106.5030608@qumranet.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm-devel , linux-kernel Return-path: To: Avi Kivity In-Reply-To: <45A66106.5030608-atKUWr5tajBWk0Htik3J/w@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Errors-To: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: kvm.vger.kernel.org Avi Kivity wrote: > dyntick-enabled guest: > - reduce the load on the host when the guest is idling > (currently an idle guest consumes a few percent cpu) You do not need dynticks for this actually. Simple no-tick-on-idle like Xen has works well enough. While you're modifying the timer code, you might also want to add proper accounting for steal time. Time during which your guest had a runnable process, but was not actually running itself, should not be accounted against the currently running process. I wonder if it would be possible to simply copy some of the timer code from Xen. They have the timing quirks worked out very well and their timer_interrupt() is pretty nice code. (Now I need to buy myself another VT box so I can help out with KVM :)) http://virt.kernelnewbies.org/ParavirtBenefits has some other features you may want to have :))) -- Politics is the struggle between those who want to make their country the best in the world, and those who believe it already is. Each group calls the other unpatriotic. ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV