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Re: [Xen-devel] [PATCH] xen: migrate vcpus only when needed

To: Ryan Harper <ryanh@xxxxxxxxxx>
Subject: Re: [Xen-devel] [PATCH] xen: migrate vcpus only when needed
From: Keir Fraser <Keir.Fraser@xxxxxxxxxxxx>
Date: Sat, 15 Apr 2006 10:10:29 +0100
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> Currently, when pinning vcpus, the target vcpu is migrated to the first
> bit in the new cpumask even if the vcpu's current process is included in
> the new mask.  This produces a non-obvious side-effect when pinning
> vcpus.

How is that non-obvious? You specify a set of CPUs on which you are
happy for that VCPU to run and Xen may run the VCPU on any of those
CPUs at any time. The current implementation's decision to change
the CPU binding the moment you specify the set of CPUs, and always
choose the lowest one, is perfectly reasonable given the specification
of that interface.

 -- Keir

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