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Re: [Xen-devel] Vcpu allocation for a newly created domU

On Wed, 2008-06-18 at 17:09 +0100, Grzegorz MiÅoÅ wrote:
> > Or is it that domU will get allocated separate vcpu's, irrespective of
> > these above vcpu's??
> Each domain, Dom0 and any DomU, will get separate VCPU(s). These are
> dynamically bound/run on physical CPUs.
This last statement has aroused another doubt...so iam deviating a bit
from the main subject.

As far as binding VCPUs to CPUs is concerned, when i looked at the
scheduler code, after chosing the next VCPU to be scheduled, during
context_switch only the curret_cpu on which the scheuler is running is
 If we look at xen/arch/x86/domain.c: __context_switch() chooses cpu
using smp_processor_id(). Also during switch_kernel_stack() the tss
struct is assigned to init_tss indexed by smp_processor_id() which
represents the current cpu.
 I was assuming the 'processor' field of the vcpu defines the binding to
a particular CPU. But it seems its not the case. Then whats the use of
processor field??

  Please correct me if my understanding is wrong.


> Cheers
> Gr(z)egor(z)

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