I'm using latest ubuntu quantal and start a kvm guest which should have 2048 MB of memory. Now after a few hours I can see that the kvm process of this guest is around 2700 MB, so 700 MB more than the guest should be able to consume. I mean a small overhead like 1% would be ok, but not 30%?!
root 8631 74.0 22.2 4767484 2752336 ? Sl Nov07 512:58 kvm -cpu kvm64 -smp sockets=1,cores=2 -cpu kvm64 -m 2048 -device virtio-blk-pci,drive=drive-virtio0,id=virtio0,bus=pci.0,addr=0xa,bootindex=100 -drive file=rbd:data/vm-disk-1,if=none,id=drive-virtio0,cache=writeback,aio=native -device virtio-net-pci,netdev=net0,bus=pci.0,addr=0x12,id=net0,mac=02:7a:86:e6:1a:6c,bootindex=200 -netdev type=tap,id=net0,vhost=on -usbdevice tablet -nodefaults -enable-kvm -daemonize -boot menu=on -vga cirrus
root 8694 0.0 0.0 0 0 ? S Nov07 0:00 [kvm-pit/8631]
How is this possible and how to prevent it?