Re: Lossy interrupts on x86_64

[Jesse Barnes <jbarnes@virtuousgeek.org>]

On Monday, September 17, 2007, Thomas Gleixner wrote:
> On Mon, 2007-09-17 at 12:13 -0700, Jesse Barnes wrote:
> > On Wednesday, September 12, 2007, Thomas Gleixner wrote:
> > > does it make any difference when you boot the box with:
> > >
> > > nohz=off
> > >
> > > on the kernel command line ?
> >
> > Yeah, that makes a difference:  the box hangs when I start
> > receiving vblank interrupts instead.  However it's not a hard hang,
> > I think X just becomes unresponsive.  I can still hit the power
> > button on the laptop and the machine shuts down gracefully, but
> > ctl-alt-delete and ctl-alt-backspace don't work.  So X is probably
> > still up and in charge of input but may not be getting any more
> > timeslices or something.
>
> Eeek, that sounds scary. Can you add "highres=off" as well ?

with nohz=off and highres=off I get a similar but not quite identical 
hang:  the mouse pointer still moves around but my desktop is still 
hung and glxgears doesn't come up.  Behavior is identical without boot 
options and with highres=off however (i.e. lossy interrupts in both 
cases).

Jesse