Re: [Xen-devel] [PATCH/RFC] Wrong account for cpus other than 0 on hotplug

[Glauber de Oliveira Costa <gcosta@xxxxxxxxxx>]

On Fri, Oct 13, 2006 at 09:33:53PM +0100, Keir Fraser wrote:
> On 13/10/06 6:50 pm, "Glauber de Oliveira Costa" <gcosta@xxxxxxxxxx> wrote:
> 
> 
> This patch turns off the missing ticks accounting entirely, as the
> runstate_info structure will never be updated. Are you sure this appears to
> be an x86_64-specific issue?

That's why I was almost sure it was wrong, and was expecting comments
:-)
Among all machines we have, it just seem to be happening in a few of
them. Besides being x86_64, they're 8-way, which can be another sort of
problem.

I just found that the offending code is in the HV itself, and not in the
guest. In arch_do_vcpu_op(), we see that the information is only passed
up to the guest, if the check (current == v) holds, which seems to be
the
true source of it. (taking the check away makes it work).

I can see no reason for this check to be there. If there is one, we
could maybe make sure it holds. (maybe calling set_current(v) on HV
side?)

Your comments on this are , as usual, very welcome ;-)


-- 
Glauber de Oliveira Costa
Red Hat Inc.
"Free as in Freedom"

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel