5 messages in com.xensource.lists.xen-cim[Xen-cim] Removing pcpus from the sch...
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Subrahmanian, Raj19 Dec 2006 07:01 
Emmanuel Ackaouy19 Dec 2006 07:13 
Keir Fraser19 Dec 2006 07:14 
Subrahmanian, Raj19 Dec 2006 07:24 
Gareth S Bestor19 Dec 2006 13:57.gif, .gif, .gif
Subject:[Xen-cim] Removing pcpus from the scheduling pool
From:Subrahmanian, Raj (raj.@unisys.com)
Date:12/19/2006 07:01:34 AM
List:com.xensource.lists.xen-cim

Emmanuel,

The Xen-CIM team has a requirement that we should be able to remove PCPUs from the scheduling pool. I quote..

* Support for ResourcePoolConfigurationService on some pool types, e.g. ProcessorPool.This functionality will support for example removing PCPUs from the pool and dedicate to management domain, thus restricting set of PCPUs available for consumption by VMs. Does xen support this? Can we mask PCPUs such that they are not available to VMs?

End quote.

What needs to be done to add this functionality to the current scheduler?

Alternately, since you mentioned that vcpu-pinning is not-soft, is it possible that if we ran a dummy VM that was pinned to the pcpus, we could do something so we would not be preempted (that would keep those pcpus from being released into the general scheduling pool)? Is that even possible? Or would it be more complicated than merely patching the scheduler and providing a path to doing it via xend?

VCPU affinity should not be soft. By the time the set affinity hypercall returns, the VCPU in question should be running on a physical CPU set in its affinity mask.

Thanks Raj