Re: maximum number of CPUs

[Matt Thomas <matt%3am-software.com@localhost>]

On Feb 23, 2012, at 12:37 PM, Manuel Bouyer wrote:

> On Thu, Feb 23, 2012 at 08:36:45AM -0700, Brook Milligan wrote:
>> I understand that at least on the i386/amd64 ports CPUs are tracked
>> with a 32-bit mask and thus at most 32 CPUs may be active.  How complex
>> is the task of removing this limitation so that a larger number of CPUs
>> may be used?
> 
> I've been locking at this code recently, and I think it's not too hard.
> I've not completely checked if the MI part has some limit too.
> 
> I intend to look at this in the near future (Xen will be a good way to work
> on this, because can start a guest with a large number of CPUs even on a UP
> hardware :); hopefully I'll have access to a 64-core system for tests too.

A developer has patches to increase the limit to 256.
Just need to wait for him to commit the changes.