Hi Avi, > If you use the dyntick clock option (the default, IIRC), and a newer > host kernel, then the kernel provides high-resolution timers, very > likely using HPET internally or some other high resolution clock and > event source.
I see. The dyntick clock seems to be more scalable than the others. I understood that '-clock hpet' is used for boosting one VM (becuase hpet gains best performance on virtio), right? I would like to try dyntick for my multiple VMs environment. > I think that for newer kernels we already have the desired accuracy. Yes. In recent versions of kvm, I didn't experience any time inaccuracy, although I had only tested under several VMs. I'll try the more number of VMs, and if time inaccuracy occurs, I would like to report that. Many thanks, ozaki-r 2008/3/23, Avi Kivity <[EMAIL PROTECTED]>: > Ryota OZAKI wrote: > > Hi all, > > > > Current kvm allows only one VM to use HPET. Is > > there a plan to implement a functionality to > > allow multiple VMs to use HPET? If so, how > > about the status of that? > > > > > > > If you use the dyntick clock option (the default, IIRC), and a newer > host kernel, then the kernel provides high-resolution timers, very > likely using HPET internally or some other high resolution clock and > event source. > > > > And I would like to ask right and wrong to > > implement the functionality in terms of need > > and efficiency (scalability and time accuracy). > > > I think that for newer kernels we already have the desired accuracy. > We're not always good at exploiting that accuracy; hence the recent > movement of the PIT implementation from userspace to the kernel. But > recent discussion leads me to believe it could have been implemented > with the userspace PIT as well. > > > -- > Any sufficiently difficult bug is indistinguishable from a feature. > > ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ kvm-devel mailing list kvm-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kvm-devel
