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RE: [Xen-devel] Too much VCPUS makes domU high CPU utiliazation

To: MaoXiaoyun <tinnycloud@xxxxxxxxxxx>, xen devel <xen-devel@xxxxxxxxxxxxxxxxxxx>
Subject: RE: [Xen-devel] Too much VCPUS makes domU high CPU utiliazation
From: "Tian, Kevin" <kevin.tian@xxxxxxxxx>
Date: Thu, 19 May 2011 11:39:14 +0800
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Thread-topic: [Xen-devel] Too much VCPUS makes domU high CPU utiliazation
>From: MaoXiaoyun
>Sent: Thursday, May 19, 2011 12:19 AM
>     I have a host with 16 physical CPUS. Dom0 has 4 VCPUS.
>    When only start a domU-A(windows 2003 x86 64rc 2) with 16 VCPUS, it starts 
>quickly and eveything is fine.

does same thing happen if you launch B/C/D after A?


>     But if I first start domU-B, which has 2VCPUS, domU-C 4VCPUS, and domU-D 
>8 VCPUS,  later I start DomUA again,
(so we have total 34 VCPUS, plus dom0), it will takes very long time for domU-A 
to start ,and during the start, its CPU
utilizaiton is around 800% from xm top, after its start, it response very slow 
in VNC, ans CPU utiliazation keeps high.
And right after I destoy other 3 domUs, domUA CPU drops to normal.
>   It might relate to CPU schedule, btw, my xen is 4.0.1.
>  Any comments? 

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