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.

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.

Thanks,

        M.
--
Jazz is not dead. It just smells funny...
_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm

Reply via email to