Daniel P. Berrange wrote:
I think it is unavoidable that every impl is going to express the
schedular
parameters in a completely different way. Thus if we're going to have an API
for fetching/updating schedular parameters then I think we need to have a
weakly typed system which is extensible to an new arbitrary fields without
requiring any API changes.
Eeeek, weak.typing--
If there is a point at which we have to say, 'sorry but libvirt does not
cover this very specialised functionality of this particular
hypervisor', then this may be it.
At the moment there is only really one hypervisor with scheduling: Xen.
The Linux scheduler exists and is used by qemu/kvm but also by many
other processes in the whole system, so it may be better for libvirt not
to fiddle with it.
By choosing not to support this in libvirt *at this time*, we aren't
preventing people from issuing direct xm commands. We're also not
closing off future possibilities. If in the future other hypervisors
come along which also have schedulers, then we can look at whether it is
possible to abstract something across all of them, and implement it in
libvirt.
This is, of course, just IMHO.
Rich.
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