Re: [PATCH] serialize suspend-resume process

[BVK Chaitanya <bayapuneni_chaitanya@symantec.com>]

Keir Fraser wrote:
> On 31/7/08 12:09, "BVK Chaitanya" <bayapuneni_chaitanya@symantec.com> wrote:
>>
>> Below patch makes suspend-resume process serialized.
> 
> It's already supposed to be serialised, and there's a loop in xen_suspend()
> to deal with up to one queued suspend request. Your patch may deal with an
> arbitrary number of queued suspend requests, but a sane dom0 control stack
> should never issue more than one suspend request in a suspend-resume cycle.
> 

Yes, but there must be a way for dom0 to know that suspend-resume cycle 
is completed.  Currently dom0 only gets suspend completed notification 
-- as part of shutdown hypercall -- but no resume 
(xenbus_suspend_cancel) completed notification.

If dom0 issues second suspend request before resume is completed a _new_ 
kthread is started and will proceed with xen_suspend in parallel.  I saw 
this hitting BUG_ON in netfront_accelerator_add_watch.

Am i missing anything?


regards,
--
bvk-chaitanya