From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rik van Riel Subject: Re: RFC: cpu frequency scaling Date: Wed, 25 Oct 2006 17:13:25 -0400 Message-ID: <453FD375.6080901@redhat.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Keir Fraser Cc: "xen-devel@lists.xensource.com" List-Id: xen-devel@lists.xenproject.org Keir Fraser wrote: > Frequency changes in dom0, please. The 'small dom0' issue is easily handled > -- create a driver domain to handle the frequency management. Or move the > potentially resource-intensive processes in dom0 out to a domU or have a cpufreq "driver domain"... OK, I'll take a look at how we can do these things. I'm guessing the way to start would be having either userspace cpufreq code polling the hypervisor for CPU load, or have a drivers/cpufreq/cpufreq_ondemand-xen.c that gets the CPU load information from the hypervisor. I'm guessing something like xentop already gets the right info from the hypervisor in a relatively efficient way, or some of the code in libvirt. I'll dig around to see what code to hook into... -- Who do you trust? The people with all the right answers? Or the people with the right questions?