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* Question about SMP support for ARM
@ 2013-08-12 12:14 Chen Baozi
  2013-08-12 12:24 ` Julien Grall
  0 siblings, 1 reply; 4+ messages in thread
From: Chen Baozi @ 2013-08-12 12:14 UTC (permalink / raw)
  To: Ian Campbell, Julien Grall; +Cc: Xen Developer List

Hi Ian & Julien,

It seems that Xen for ARM is not support SMP boot by default since "max_phys_cpus" is not set?

Cheers,

Baozi

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: Question about SMP support for ARM
  2013-08-12 12:14 Question about SMP support for ARM Chen Baozi
@ 2013-08-12 12:24 ` Julien Grall
  2013-08-12 12:28   ` Chen Baozi
  0 siblings, 1 reply; 4+ messages in thread
From: Julien Grall @ 2013-08-12 12:24 UTC (permalink / raw)
  To: Chen Baozi; +Cc: Ian Campbell, Xen Developer List

On 08/12/2013 01:14 PM, Chen Baozi wrote:
> Hi Ian & Julien,

Hi,

> It seems that Xen for ARM is not support SMP boot by default since "max_phys_cpus" is not set?

max_phys_cpus allows use to restrict the number of cpus handled by Xen.
It's only used to set NR_CPUS. If the former is not set, Xen will use
128 as default value (see include/asm-arm/config.h).

Cheers,

-- 
Julien Grall

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: Question about SMP support for ARM
  2013-08-12 12:24 ` Julien Grall
@ 2013-08-12 12:28   ` Chen Baozi
  2013-08-12 12:40     ` Julien Grall
  0 siblings, 1 reply; 4+ messages in thread
From: Chen Baozi @ 2013-08-12 12:28 UTC (permalink / raw)
  To: Julien Grall; +Cc: Ian Campbell, Xen Developer List

On Mon, Aug 12, 2013 at 01:24:40PM +0100, Julien Grall wrote:
> On 08/12/2013 01:14 PM, Chen Baozi wrote:
> > Hi Ian & Julien,
> 
> Hi,
> 
> > It seems that Xen for ARM is not support SMP boot by default since "max_phys_cpus" is not set?
> 
> max_phys_cpus allows use to restrict the number of cpus handled by Xen.
> It's only used to set NR_CPUS. If the former is not set, Xen will use
> 128 as default value (see include/asm-arm/config.h).

Thanks.

Then I think I need to find out why the log says:

Waiting for 0 other CPUs to be ready
...
Brought up 1 CPUs

since I do have got 2 cores on OMAP5 and added "kick cpu" codes to
mode_switch.S next.

Cheers,

Baozi

> 
> Cheers,
> 
> -- 
> Julien Grall

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: Question about SMP support for ARM
  2013-08-12 12:28   ` Chen Baozi
@ 2013-08-12 12:40     ` Julien Grall
  0 siblings, 0 replies; 4+ messages in thread
From: Julien Grall @ 2013-08-12 12:40 UTC (permalink / raw)
  To: Chen Baozi; +Cc: Ian Campbell, Xen Developer List

On 08/12/2013 01:28 PM, Chen Baozi wrote:
> On Mon, Aug 12, 2013 at 01:24:40PM +0100, Julien Grall wrote:
>> On 08/12/2013 01:14 PM, Chen Baozi wrote:
>>> Hi Ian & Julien,
>>
>> Hi,
>>
>>> It seems that Xen for ARM is not support SMP boot by default since "max_phys_cpus" is not set?
>>
>> max_phys_cpus allows use to restrict the number of cpus handled by Xen.
>> It's only used to set NR_CPUS. If the former is not set, Xen will use
>> 128 as default value (see include/asm-arm/config.h).
> 
> Thanks.
> 
> Then I think I need to find out why the log says:
> 
> Waiting for 0 other CPUs to be ready
> ...
> Brought up 1 CPUs
> 
> since I do have got 2 cores on OMAP5 and added "kick cpu" codes to
> mode_switch.S next.

Xen uses the device tree to know the real number of cpus.

You should have a node cpus similar to :

cpus {
   cpu@0 {
     device_type = "cpu";
     reg = "0";
   };
   cpu@1 {
     device_type = "cpu";
     reg = "1";
   };
};

Cheers,

-- 
Julien Grall

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2013-08-12 12:40 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2013-08-12 12:14 Question about SMP support for ARM Chen Baozi
2013-08-12 12:24 ` Julien Grall
2013-08-12 12:28   ` Chen Baozi
2013-08-12 12:40     ` Julien Grall

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