Re: [Xen-devel] Cpu pools discussion

To:	Tim Deegan <Tim.Deegan@xxxxxxxxxx>
Subject:	Re: [Xen-devel] Cpu pools discussion
From:	Juergen Gross <juergen.gross@xxxxxxxxxxxxxx>
Date:	Tue, 28 Jul 2009 12:15:47 +0200
Cc:	George Dunlap <dunlapg@xxxxxxxxx>, Zhigang Wang <zhigang.x.wang@xxxxxxxxxx>, "xen-devel@xxxxxxxxxxxxxxxxxxx" <xen-devel@xxxxxxxxxxxxxxxxxxx>, Keir Fraser <Keir.Fraser@xxxxxxxxxxxxx>
Delivery-date:	Tue, 28 Jul 2009 03:16:16 -0700
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Tim Deegan wrote:
> At 01:41 +0100 on 28 Jul (1248745277), Zhigang Wang wrote:
>> A usecase from me: I want a pool that passthrough pcpus to the mission
>> critical domains. A scheduling algorithm will map vcpus to pcpus one
>> by one in this pool. That will implement a reliable hard partitioning.
>> although it will lose some benefit of virtualization.
> 
> That's easily done by setting affinity masks in the tools, without
> needing any mechanism in Xen.

More or less.
You have to set the affinity masks for ALL domains to avoid scheduling on the
"special" cpus.
You won't have reliable scheduling weights any more.


Juergen

-- 
Juergen Gross                 Principal Developer Operating Systems
TSP ES&S SWE OS6                       Telephone: +49 (0) 89 636 47950
Fujitsu Technolgy Solutions               e-mail: juergen.gross@xxxxxxxxxxxxxx
Otto-Hahn-Ring 6                        Internet: ts.fujitsu.com
D-81739 Muenchen                 Company details: ts.fujitsu.com/imprint.html

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Re: [Xen-devel] Cpu pools discussion