Subject: Re: HEAD instability on Xen
To: Andrew Doran <ad@NetBSD.org>
From: Manuel Bouyer <firstname.lastname@example.org>
Date: 11/19/2007 12:47:26
On Mon, Nov 19, 2007 at 12:00:00PM +0100, Manuel Bouyer wrote:
> On Sun, Nov 18, 2007 at 11:12:38PM +0100, Manuel Bouyer wrote:
> > On Sun, Nov 18, 2007 at 10:08:03PM +0000, Andrew Doran wrote:
> > >
> > > Acutally, it already has all the necessary changes. Is there a point where
> > > the kernel is entered with Xen that the direction flag might not be cleared?
> > I'll have a look. Could it be a missing lock or splxx() in the pmap ?
> > > I can't see one. It is cleared for the copyout() in the traceback that you
> > > posted.
> > >
> > > > I've also seen it in the pool code. It was always handling a trap after a
> > > > copyin or copyout though.
> > >
> > > I did many hours of low-memory stress testing on the updated pool code
> > > before checking it in, so I don't believe that there is an (obvious) problem
> > > there. It could be perhaps be related to the removal of the _CPU options.
> > No, I've seen it with a kernel from before the _CPU options removal
> > (the bouyer-xenamd64-base2 tag in src/sys).
> I've tracked it down to a change between 2007.11.05.10.25.03 and
> 2007.11.08.10.25.03 on HEAD. Here's another instance of the panic (with
It's between 2007.11.07.00.00.00 and (2007.11.07.02.00.00 +
Manuel Bouyer, LIP6, Universite Paris VI. Manuel.Bouyer@lip6.fr
NetBSD: 26 ans d'experience feront toujours la difference