[et-mgmt-tools] [PATCH] Add the option to guard maximums of the number of virtual CPU by the number of physical CPU

[Hugh Brock]

Masayuki Sunou wrote:
> Hi
> 
> In virt-install, the maximum of the number of virtual CPU are not guarded
> by the number of physical CPU. 
> As a result , the domain slows down when the user set many virtual CPUs
> by mistake. 
> 
> Therefore, I contribute the patch that adds the option to guard maximums
> of the number of virtual CPU by the number of physical CPU. 
> 
> 
> Signed-off-by: Masayuki Sunou <fj1826dm at aa.jp.fujitsu.com>
> 
> Thanks,
> Masayuki Sunou

Actually, we had included this limit early on, but we decided to merely 
warn the user that excess vcpus can be bad. The thought was that a user 
might define a domain somewhere, test it, then migrate it to a machine 
with more CPUs, in which case we would need to allow them to define more 
virtual CPUs than are physically present.

Unless you can think of a compelling reason not to allow a user to do 
the above, I think we should not take this patch and leave the vcpu 
setting unbounded. However if you would like to send a patch that warns 
the user without imposing a hard limit, I think that would be reasonable.

Take care,
--Hugh

-- 
Red Hat Virtualization Group http://redhat.com/virtualization
Hugh Brock           | virt-manager http://virt-manager.org
hbrock at redhat.com    | virtualization library http://libvirt.org