Hi Marc, On 2020/1/15 21:50, Marc Zyngier wrote: > Hi Shaokun, > > On 2020-01-14 14:20, Shaokun Zhang wrote: >> Hi Marc, >> >> On activation, VMAPP command is followed by a VINVALL, which could be >> quite expensive for the start-up of virtual machine. If a vpeid is allowed >> successfully, it is not used in system. > > How expensive? This is exactly similar to what happens on a physical machine > where we perform an INVALL on MAPC. And yet you don't complain about that. > Agree, I didn't consider this before. > Please provide numbers. > >> We may consider put VINVALL to deactivation to ensure all cache of certain >> vpeid is invalid, to simplify activation. We consider start-up may be more >> common and more time-consuming-sensitive than shutdown process. > > In my world, they cost the same thing, and happen just as often. Also, I want > guarantees that on VMAPP, there is no stale information even if this is the > first time we're using this VPEid (who knows what happens over kexec, for > example). > >> Do you think it's all right? > > I don't, for the reasons stated above. You also provide no numbers showing > how bad the overhead is, so I'm left guessing. > Got it, you are right :-). Thanks for your explaination Shaokun > Thanks, > > M. _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
