From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH 0/2][KVM] guest time accounting Date: Mon, 13 Aug 2007 17:19:49 +0300 Message-ID: <46C06885.3020908@qumranet.com> References: <46BC8B39.6050202@bull.net> <46C00FC1.1070306@qumranet.com> <46C012A8.2040908@bull.net> <200708131615.42643.borntraeger@de.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org, Laurent Vivier , linux-kernel , virtualization To: Christian Borntraeger Return-path: In-Reply-To: <200708131615.42643.borntraeger-tA70FqPdS9bQT0dZR+AlfA@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 Christian Borntraeger wrote: > Am Montag, 13. August 2007 schrieb Laurent Vivier: > >>> [copying Ingo and Rusty] >>> > > @Avi, seems that sourceforge is mangling the cc list? > > It's not configured to do so. Can you be more specific? >>> The patches look good. A couple of comments: >>> >>> - perhaps the new fields should be guarded by a #ifdef CONFIG_HYPERVISOR >>> (selected by CONFIG_KVM)? that way the (minor) additional overhead is >>> only incurred if it can possibly be used. I imagine that our canine >>> cousin will want to use this as well. >>> >> There is also a CONFIG_VIRTUALIZATION and a CONFIG_VIRT_CPU_ACCOUNTING (from >> s390 and powerpc) Which one to use ? >> > > CONFIG_VIRT_CPU_ACCOUNTING is used for the precise accouting of user,system, > steal and irq time on these platforms and is not what you want for the on/off > decision. > Ah, ok. >> I'm wondering if we can have a more accurate accounting: >> >> - For the moment we add all system time since the previous entering to the >> VCPU to the guest time (and I guess there is some real system time in >> it ???) >> - Perhaps we can sum nanoseconds spent in the VCPU and add it to cpustat >> when these ns are greater than 1 ms ? (I'm trying to make something in this >> > way) > > If you look at the patch I have posted some minutes ago, I use a method > similar to irq_enter and irq_exit to separate real system time from guest > time. Yes. This is orthogonal to the current accounting patch and should make a nice extension. It's probably useful with dynamic tick where timer interrupts can be rare. -- error compiling committee.c: too many arguments to function ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/