From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030490AbXALFez (ORCPT ); Fri, 12 Jan 2007 00:34:55 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1160998AbXALFez (ORCPT ); Fri, 12 Jan 2007 00:34:55 -0500 Received: from mx1.redhat.com ([66.187.233.31]:44005 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030490AbXALFez (ORCPT ); Fri, 12 Jan 2007 00:34:55 -0500 Message-ID: <45A71DEA.9020307@redhat.com> Date: Fri, 12 Jan 2007 00:34:34 -0500 From: Rik van Riel Organization: Red Hat, Inc User-Agent: Thunderbird 1.5.0.7 (X11/20061008) MIME-Version: 1.0 To: Avi Kivity CC: Ingo Molnar , kvm-devel , linux-kernel Subject: Re: kvm & dyntick References: <45A66106.5030608@qumranet.com> In-Reply-To: <45A66106.5030608@qumranet.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@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.