On Fri, Jul 02, 2010 at 08:38:37PM +0400, Boris Dolgov wrote: > On Fri, Jul 2, 2010 at 11:57 AM, Srivatsa Vaddagiri <vatsa@xxxxxxxxxx> wrote: > >> Is it possible to limit cpu usage be VM when using qemu+kvm? > > > > Have you checked cpu controller? > It is very interesting. Looks like it is something, that I need. > So, limiting qemu process will limit cpu usage for the container? > I think, i will be able to configure it to provide guaranted cpu to > containers in that way. Note that shares control how much cpu bandwidth a VM gets _relative_ to other active VMs and hence is not a absolute measure of how much CPU capacity is provided to a particular VM. If the number of VMs deployed on a server and their relative priority remains static in general, then shares can be used as both "guarantee" and "limit" mechanism. > But what happens with the VM when qemu process is paused by the > scheduler? Will this time be counted as idle time for VM's cpu, No - it should be accounted as "runqueue wait time". > or it will be added to the state, which was used when qemu process was > paused? The runqueue wait time should reflect as "steal" time for the VMs. top command should show the steal time for a VM (look for 'st'), although I am not 100% sure whether steal time is reported in case of KVM guests. > > Why do you want to modify /proc/cpuinfo of VMs? > Just for information about the limits for the VMs' owners. Sounds like a cool idea - although not sure whether cpuinfo is the right place. You can try sending a patch and find out what the community thinks of it! - vatsa -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
