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Re: [Xen-devel] how many processors does xen support in hardware?



Oh, right, yes that is Linux's configurable maximum (itself fairly arbitrary
really). You can't actually use that number on Xen, so don't set it so high.
Simple really. :-)

 -- Keir

On 24/8/07 19:00, "pradeep singh" <rautelap@xxxxxxxxx> wrote:

> On Friday 24 August 2007 20:19:07 Keir Fraser wrote:
>> Where did you get this number 255 from?
> 
> Sorry i meant, while i compile the xen kernel i can configure kernel upto a
> max of 255. right?
> 
> And i guess that means the number of CPUs you can compile your SMP kernel to
> work with. 
> what did i miss? :-/
> 
> thanks
> --pradeep
>> 
>>  K.
>> 
>> On 24/8/07 15:32, "pradeep singh rautela" <rautelap@xxxxxxxxx> wrote:
>>> On 8/24/07, Puthiyaparambil, Aravindh
>> 
>> <aravindh.puthiyaparambil@xxxxxxxxxx>
>> 
>>> wrote:
>>> Xen x86_32/PAE supports 32 logical CPUs. This is a hard limit and
>>> there is no easy way to increase this.
>>> 
>>> Xen x86_64 supports 64 logical
>>> CPUs. You need to compile Xen with max_phys_cpus=64 to enable this
>>> support. If you want to go beyond 126 LCPUs some patching is needed.
>>> 
>>> I guess you can
>>> theoretically go up to 255 but I think you might run out of GDT slots
>>> before that.
>> 
>> Right, so why keep 255 there at all? I mean why hard code it  to a
>> 
>>> max
>> 
>> 255 then?Put it at a number a little near or higher than what Xen
>> 
>>> is
>> 
>> actually capable of.
>> 
>> thanks
>> 
>>> Aravindh Puthiyaparambil
>>> Virtualization
>>> Engineer
>>> Virtual Systems Development
>>> Unisys, Tredyffrin PA
>>> 
>>> 
>>> -----Original Message-----
>>> From: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
>>> [mailto:xen-devel-bounces@xxxxxxxxxxxxxxxxxxx] On Behalf Of tgh
>>> Sent:
>>> Friday, August 24, 2007 7:31 AM
>>> To: pradeep singh rautela
>>> Cc:
>>> xen-devel@xxxxxxxxxxxxxxxxxxx
>>> Subject: Re: [Xen-devel] how many processors
>>> does xen support in hardware?
>>> 
>>> pradeep singh rautela 写道:
>>>> On 8/24/07,
>>> 
>>> tgh <tianguanhua@xxxxxxxxxx> wrote:
>>>>> hi
>>>>>    how many processors
>>> 
>>> does xen support in hardware for the practical
>>> 
>>>>> system?
>>>> 
>>>> Thats
>>> 
>>> would be 255 i guess.
>>> 
>>> thank you for your reply
>>> but I want to kown the
>>> max number of hardware cpus the xen could
>>> support, or the xen's scalability
>>> in the aspect of cpu number,not in the
>>> aspect of the VM number
>>> 
>>> 
>>> thanks
>>> 
>>>> thanks
>>>> 
>>>>>   what is the max number of processors in
>>> 
>>> the practice system running
>>> 
>>>>> under xen ?
>>>>> 
>>>>> 
>>>>> 
>>>>> Thanks in
>>> 
>>> advance
>>> 
>>>>> _______________________________________________
>>> 
>>> Xen-devel mailing list
>>> 
>>>>> Xen-devel@xxxxxxxxxxxxxxxxxxx
>>> 
>>> http://lists.xensource.com/xen-devel
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> _______________________________________________
>>> Xen-devel mailing list
>>> 
>>> Xen-devel@xxxxxxxxxxxxxxxxxxx
>>> http://lists.xensource.com/xen-devel
>> 
>> --
>> 
>> --
>> pradeep singh rautela
>> 
>> "Genius is 1% inspiration, and 99% perspiration" -
>> 
>>> not me :)
>>> 
>>> _______________________________________________
>>> Xen-devel mailing list
>>> Xen-devel@xxxxxxxxxxxxxxxxxxx
>>> http://lists.xensource.com/xen-devel
> 
> 



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