On Tue, 2007-03-06 at 17:44 -0800, Dan Hecht wrote: > >>> 2) As I said above. The time accounting for virtualization needs to be > >>> fixed in a generic way. > >>> > >>> I'm not going to accept some weird hackery for virtualization, which is > >>> of exactly ZERO value for the kernel itself. Quite the contrary it will > >>> make the cleanup harder and introduce another hard to remove thing, > >>> which will in the worst case last for ever. > >>> > >> Okay, to confirm I'm on the same page as you, you want to move process > >> time accounting from being periodic sampled based to being trace based? > >> i.e. at the system-call/interrupt boundaries, read clocksource and > >> compute directly the amount of system/user/process time? > > > > At least for the paravirt guests this is the correct approach. Once the > > CPU vendors come up with a sane solution for a reliable and fast clock > > source we might use that on real hardware as well. > > > > I thought your preference was to not do things differently from real > hardware? I guess this case you are okay with since you'd like to see > the real hardware case follow eventually? Real hardware _IS_ broken and slow. If we add the facilities for virtualization we want it in a way, which is usable by real hardware as well. > > Yes, with todays hardware it is simply a PITA. PowerPC has some basic > > support for this though, IIRC. > > > > I think S390 maybe too. One more reason to make it a generic solution rather than some extra hackery. tglx _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxx https://lists.osdl.org/mailman/listinfo/virtualization
