Re: SMP in dom0

Hi Manuel,

Thanks for pointing out the specific problem areas. Based on your suggestion we will go ahead and modify the code and test it.

Based on the test result, we will share the code back to the community.

However, meanwhile we are also interested in knowing if there are other members who are working on the same, we would like to collaborate and work with them on the issue.

Looking forward to hear from the team working on resolving SMP issue in dom0.

Thanks,

Nagaraj

On Wed, Apr 8, 2015 at 8:00 PM, Manuel Bouyer <bouyer%antioche.eu.org@localhost> wrote:

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
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