Re: [PATCH v9 3/3] cpus-common: implement dirty page limit on vCPU

[Peter Xu]

On Mon, Dec 06, 2021 at 10:56:00PM +0800, Hyman wrote:
> > I found that it'll be challenging for any human being to identify "whether
> > he/she has turned throttle off for all vcpus"..  I think that could be 
> > useful
> > when we finally decided to cancel current migration.
> That's question, how about adding an optional argument "global" and making
> "cpu-index", "enable", "dirty-rate" all optional in "vcpu-dirty-limit",
> keeping the "cpu-index" and "global" options mutually exclusive?
> { 'command': 'vcpu-dirty-limit',
>   'data': { '*cpu-index': 'int',
>             '*global': 'bool'
>             '*enable': 'bool',
>             '*dirty-rate': 'uint64'} }
> In the case of enabling all vcpu throttle:
> Either use "global=true,enable=true,dirty-rate=XXX" or
> "global=true,dirty-rate=XXX"
> 
> In the case of disabling all vcpu throttle:
> use "global=true,enable=false,dirty-rate=XXX"
> 
> In other case, we pass the same option just like what we did for specified
> vcpu throttle before.

Could we merge "cpu-index" and "global" somehow?  They're mutual exclusive.

For example, merge them into one "vcpu" parameter, "vcpu=all" means global,
"vcpu=1" means vcpu 1.  But then we'll need to make it a string.

-- 
Peter Xu