On 4/27/22 19:16, Dr. David Alan Gilbert wrote:
* Paolo Bonzini ([email protected]) wrote:
On 4/27/22 17:16, Dr. David Alan Gilbert wrote:
* Paolo Bonzini ([email protected]) wrote:
On 4/27/22 14:34, Dr. David Alan Gilbert wrote:
If I specify a 'vm' it's not obvious to me whether I'd get NICs and
block devices in the future?
VM would not get those (it's global statistics), but the size could balloon
if you specify no target at all.
Adding a syntax for 'all' into the vcpus list would fix that?
I don't like having special syntax. The current QAPI just doesn't filter
what is not in the arguments.
Is there a object that represents the set of all vcpus?
No.
If it was easy to create one then you could remove all the special
casing of vCPUs/VM target?
(It feels really like you should call a 'stats' method on the target)
There are two possibilities for that:
1) add statistics to an object like /machine, that would return the
sum/max of the statistics. Advantage: you have an easy way to summarize
stats without reading many KBs of data. Disadvantage: it doesn't do what
you're asking. :) But it may be an interesting addition.
2) make query-stats return the statistics for all objects below a given
QOM path, and then the caller would pass / or /machine as the target.
Both make sense, but neither extends easily to the case where you don't
have a QOM path, as is the case for block or network devices.
Unfortunately, both of them are prime candidates for extending the
subsystem, so they can't be dismissed easily, and that is why
implemented neither of them.
If block or network devices were QOM, it would be possible and easy to
have a single "qom-path" argument to replace both "target" and the
sub-records like StatsVCPUFilter.
Paolo
