On Thu, 2008-03-06 at 14:56 -0600, Anthony Liguori wrote: > Avi Kivity wrote: > > > >> The thing I'm trying to get at is a quantitative statement about why > >> moving the pit into the kernel is the right thing. I'll try to give > >> the patches a try myself in the next couple of days. I don't think > >> it's obvious that it's the right thing to do without some sort of > >> benchmark supporting it. > >> > > > > Playing a movie is better than any benchmark; it reflects actual user > > experience in a real and important use case. Benchmarks are > > substitutes for real use cases, not the goal of the optimization. > > I tried out WinXP with the standard HAL and the in-kernel APIC patches. > I did not see any appreciable improvement in multimedia playback (video > or audio). I still get the same amount of jitters. I've tried with and > without -tdf too. > > So far, the smoothest play back I've gotten is using the ACPI HAL. Can > you point to a particular example where you see an improvement? Perhaps > a divx or movie trailer that is better with it than without it? >
ACPI HAL should perform good. The in kernel PIT should fix time drift on standard HAL when playing movies (pit freq -> 1000hz) and the host cpu is loaded. If the host is not loaded you might not see the drift. Use kernel build or tgz + taskset to load the cpu. Without the patches in-kernel PIC should time drift and userspace PIC + -tdf shouldn't. As for quality, sometimes when time drifts the movies looks smoother but that's not really the required result. > Regards, > > Anthony Liguori > > ------------------------------------------------------------------------- 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
