Re: [Xen-devel] vpt periodic timer and vhpet

[Keir Fraser <keir.fraser@xxxxxxxxxxxxx>]

On 06/02/2009 03:55, "Tian, Kevin" <kevin.tian@xxxxxxxxx> wrote:

> Just noted vpt create_periodic_time is now changed to require
> two parameters: period and delta, by 18694 which ports vhpet
> to vpt framework. I'm not quite clear the necessity here. It doesn't
> matter whether 1st expiration must be accurately hit. vhpet
> main counter and per-channel comparators are updated only
> when guest tries to read. Is there any special tricks on hpet
> since all other periodic timers are simply filling same value for
> period and delta?
> 
> I ask because we're considering some proactive timer alignment
> besides existing range timer, while above change seems to implicate
> something that we may neglect.

See the changeset that introduced the delta (18694), see the changeset
comment and the comment above use of create_periodic_time() in hpet.c.
Decide if you agree, and if you don't then ask the author, cc'ing the list.

 -- Keir



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