Dong, Eddie wrote: >> We found that using an hrtimer enabled host with >> CONFIG_HZ=1000 improves >> things. However I don't think that it's as accurate as 7 >> seconds in 20 >> minutes (that's better than 1% accuracy), so probably more work is >> needed in qemu to correct time drift. >> >> > Time virtualization for HVM is always a headache, no simple way can > provide > accurate source :-( > Per current KVM time virtualization policy, drop of jiffies or redundant > jiffies > may happen frequently.
There is some code in kvm's qemu to track dropped ticks and reinject them. The code is disabled because it doesn't work well. > BTW, even in Xen, we are not satisfied with the > time > virtualization especially for TSC timer. > I don't think tsc can be virtualized well. It's too fast. > Some modification in guest Linux side is really needed, maybe somebody > can bring this issue to virtualization mini summit? > Linux already has support for paravirtualized time, we just need to use it. -- error compiling committee.c: too many arguments to function ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ kvm-devel mailing list kvm-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kvm-devel
