Re: Dom0: machine hang with cpuctl

[Christoph Egger <Christoph_Egger%gmx.de@localhost>]

On Wednesday 04 June 2008 16:39:39 Manuel Bouyer wrote:
> On Mon, Jun 02, 2008 at 11:37:25PM +0200, Christoph Egger wrote:
> > Hi!
> >
> >
> > In a amd64 Dom0 (4.99.64), "cpuctl identify 0" works fine on VGA.
> > In a ssh session on that machine, the same command makes the machine
> > hang - the command itself does not run and there's no reaction on the
> > shell.
> >
> >
> > With a GENERIC kernel, "cpuctl identify 0" works both on VGA and
> > (ssh) remote.
> >
> >
> > When the machine hangs, I can ping the machine, I can break into ddb
> > on VGA. Things I type on VGA don't appear on the display. But in ddb,
> > the keyboard works normally.
> >
> > A backtrace in ddb is always the same:
> >
> > wskbd_translate() at netbsd:wskbd_translate+0xb1e
> > wskbd_input() at netbsd:wskbd_input+0xc6
> > pckbd_input() at netbsd:pckbd_input+0x54
> > pckbcintr() at netbsd:pckbcintr+0x81
> > Xresume_xenev6() at netbsd:Xresume_xenevt+0x55
> > --- interrupt ---
> > Xspllower() at netbsd:Xspllower+0xe
> > idle_loop() at netbsd:idle_loop+0x86
> >
> >
> > Can anyone reproduce this?
>
> I can. It seems related to CPU binding: if I run cpuctl identify as
> non-root, it works. Running it as root from the serial console work too.

I can also reproduce this in a NetBSD/Xen DomU, too. But it works
as non-root for me.

Christoph