Re: Xen4.2 S3 regression?

[Andrew Cooper <andrew.cooper3@citrix.com>]

On 23/08/12 19:03, Ben Guthro wrote:
> I did some more bisecting here, and I came up with another changeset
> that seems to be problematic, Re: IRQs
>
> After bisecting the problem discussed earlier in this thread to the
> changeset below,
> http://xenbits.xen.org/hg/xen-unstable.hg/rev/0695a5cdcb42
>
>
> I worked past that issue by the following hack:
>
> --- a/xen/common/event_channel.c
> +++ b/xen/common/event_channel.c
> @@ -1103,7 +1103,7 @@ void evtchn_destroy_final(struct domain *d)
>  void evtchn_move_pirqs(struct vcpu *v)
>  {
>      struct domain *d = v->domain;
> -    const cpumask_t *mask = cpumask_of(v->processor);
> +    //const cpumask_t *mask = cpumask_of(v->processor);
>      unsigned int port;
>      struct evtchn *chn;
>
> @@ -1111,7 +1111,9 @@ void evtchn_move_pirqs(struct vcpu *v)
>      for ( port = v->pirq_evtchn_head; port; port = chn->u.pirq.next_port )
>      {
>          chn = evtchn_from_port(d, port);
> +#if 0
>          pirq_set_affinity(d, chn->u.pirq.irq, mask);
> +#endif
>      }
>      spin_unlock(&d->event_lock);
>  }
>
>
> This seemed to work for this rather old changeset, but it was not
> sufficient to fix it against the 4.1, or unstable trees.
>
> I further bisected, in combination with this hack, and found the
> following changeset to also be problematic:
>
> http://xenbits.xen.org/hg/xen-unstable.hg/rev/c2cb776a5365
>
>
> That is, before this change I could resume reliably (with the hack
> above) - and after I could not.
> This was surprising to me, as this change also looks rather innocuous.

And by the looks of that changeset, the logic in fixup_irqs() in irq.c
was changed.

Jan: The commit message says "simplify operations [in] a few cases". 
Was the change in fixup_irqs() deliberate?

~Andrew

>
>
> Naturally, backing out this change seems to be non-trivial against the
> tip, since so much around it has changed.
>

-- 
Andrew Cooper - Dom0 Kernel Engineer, Citrix XenServer
T: +44 (0)1223 225 900, http://www.citrix.com