Re: [Xen-devel] [PATCH 26/60] xen: let vcpu_create() select processor

[Jan Beulich <JBeulich@xxxxxxxx>]

>>> On 28.05.19 at 12:32, <jgross@xxxxxxxx> wrote:
> Today there are two distinct scenarios for vcpu_create(): either for
> creation of idle-domain vcpus (vcpuid == processor) or for creation of
> "normal" domain vcpus (including dom0), where the caller selects the
> initial processor on a round-robin scheme of the allowed processors
> (allowed being based on cpupool and affinities).
> 
> Instead of passing the initial processor to vcpu_create() and passing
> on to sched_init_vcpu() let sched_init_vcpu() do the processor
> selection. For supporting dom0 vcpu creation use the node_affinity of
> the domain as a base for selecting the processors. User domains will
> have initially all nodes set, so this is no different behavior compared
> to today.

This last aspect is a result of how the tool stack currently works, but
as long as there's a separate XEN_DOMCTL_max_vcpus there's no
real guarantee that the domain affinity mask hasn't changed already,
is there? I don't mind such a dependency, since XEN_DOMCTL_max_vcpus
is scheduled to go away anyway, but I think this should be called out
explicitly here.

Jan
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/xen-devel