On 8/20/07, malc <[EMAIL PROTECTED]> wrote: > On Mon, 20 Aug 2007, Luca Tettamanti wrote: > > > Il Sun, Aug 19, 2007 at 10:31:26PM +0300, Avi Kivity ha scritto: > >> Luca wrote: > >>> On 8/19/07, Luca Tettamanti <[EMAIL PROTECTED]> wrote: > >>> > >>>> +static uint64_t qemu_next_deadline(void) { > >>>> + uint64_t nearest_delta_us = ULLONG_MAX; > >>>> + uint64_t vmdelta_us; > >>>> > >>> > >>> Hum, I introduced a bug here... those vars should be signed. > >>> > >>> On the overhead introduced: how do you measure it? > >>> > >>> > >> > >> Run a 100Hz guest, measure cpu usage using something accurate like > >> cyclesoak, with and without dynticks, with and without kvm. > > > > Ok, here I've measured the CPU usage on the host when running an idle > > guest. > > [...] > The upshot is this - if you have used any standard utility (iostat, > top - basically anything /proc/stat based) the accounting has a fair > chance of being inaccurate. If cyclesoak is what you have used then > the results should be better, but still i would be worried about > them.
Yes, I've used cyclesoak. Luca