Re: SMP in dom0

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

On Tue, Apr 07, 2015 at 06:41:13PM +0530, Nagaraj Math wrote:
> Hi,
> 
> I am working on a product where I would like to have SMP in dom0.
> I have come across couple of forums, where it has been discussed, currently
> SMP is not supported in NetBSD in dom0 because back end drivers are not SMP
> safe.
> Does it mean that, as kernel NetBSD is SMP compatible in dom0, it is the
> drivers who needs to be fixed to support SMP? How big is this effort, my
> team would like to support in making SMP functional in dom0.

Yes, I think it's only the drivers that need some work.
domU kernels are already SMP-capable so most of the work is done.

The problem is, I guess, mostly in the backend drivers such as
arch/xen/xen/privcmd.c
arch/xen/xen/xenevt.c
the backend drivers arch/xen/xen/xennetback_xenbus.c and
arch/xen/xen/xbdback_xenbus.c
maybe arch/xen/x86/xen_shm_machdep.c

(basically, you need to replace spl-style locking with mutexes).

-- 
Manuel Bouyer <bouyer%antioche.eu.org@localhost>
     NetBSD: 26 ans d'experience feront toujours la difference
--