Yes, this works. Thanks very much!
>From: Juergen Gross [mailto:juergen.gross@xxxxxxxxxxxxxx]
>Sent: Wednesday, November 10, 2010 2:04 PM
>To: Jiang, Yunhong
>Cc: George Dunlap; xen-devel@xxxxxxxxxxxxxxxxxxx; Dong, Eddie; Zhang, Xiantao
>Subject: Re: [Xen-devel] RE: The caculation of the credit in credit_scheduler
>On 11/10/10 06:55, Jiang, Yunhong wrote:
>>> -----Original Message-----
>>> From: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
>>> [mailto:xen-devel-bounces@xxxxxxxxxxxxxxxxxxx] On Behalf Of Juergen Gross
>>> Sent: Wednesday, November 10, 2010 1:46 PM
>>> To: Jiang, Yunhong
>>> Cc: George Dunlap; xen-devel@xxxxxxxxxxxxxxxxxxx; Dong, Eddie; Zhang,
>>> Subject: Re: [Xen-devel] RE: The caculation of the credit in
>>> On 11/10/10 03:39, Jiang, Yunhong wrote:
>>>>> -----Original Message-----
>>>>> From: George Dunlap [mailto:George.Dunlap@xxxxxxxxxxxxx]
>>>>> Sent: Tuesday, November 09, 2010 10:27 PM
>>>>> To: Jiang, Yunhong
>>>>> Cc: xen-devel@xxxxxxxxxxxxxxxxxxx; Dong, Eddie; Zhang, Xiantao
>>>>> Subject: Re: The caculation of the credit in credit_scheduler
>>>>> On 05/11/10 07:06, Jiang, Yunhong wrote:
>>>>>> The reason is how the credit is caculated. Although the 3 HVM domains is
>>>>> to 2 PCPU and share the 2 CPUs, they will all get 2* 300 credit when
>>>>> That means the I/O intensive HVM domain will never be under credit, thus
>>>>> preempt the CPU intensive whenever it is boost (i.e. after I/O access to
>>>>> it is set to be TS_UNDER only at the tick time, and then, boost again.
>>>>> I suspect that the real reason you're having trouble is that pinning and
>>>>> the credit mechanism don't work very well together. Instead of pinning,
>>>>> have you tried using the cpupools interface to make a 2-cpu pool to put
>>>>> the VMs into? That should allow the credit to be divided appropriately.
>>>> I have a quick look in the code, and seems the cpu pool should not help on
>>> situation. The CPU poll only cares about the CPUs a domain can be
>>> scheduled, but
>>> not about the credit caculation.
>>> With cpupools you avoid the pinning. This will result in better credit
>>> calculation results.
>> My system is doing testing, so I can't do the experiment now, but I'm not
>> sure if
>the cpupool will help the credit caculation.
>>> From the code in csched_acct() at "common/sched_credit.c", the credit_fair
>caculated as followed, and the creadt_fair's original value is caculated by
>pcpu's credit, without considering the cpu poll.
>> credit_fair = ( ( credit_total
>> * sdom->weight
>> * sdom->active_vcpu_count )
>> + (weight_total - 1)
>> ) / weight_total;
>> Or did I missed anything?
>The scheduler sees only the pcpus and domains in the pool, as it is cpupool
>BTW: the credit scheduler's problem with cpu pinning was the main reason for
>Juergen Gross Principal Developer Operating Systems
>TSP ES&S SWE OS6 Telephone: +49 (0) 89 3222 2967
>Fujitsu Technology Solutions e-mail: juergen.gross@xxxxxxxxxxxxxx
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