Re: Linux 2.6.25-rc4

From: Jens Axboe
Date: Thu Mar 06 2008 - 08:55:48 EST


On Thu, Mar 06 2008, Bartlomiej Zolnierkiewicz wrote:
> On Thursday 06 March 2008, Ingo Molnar wrote:
> >
> > * Bartlomiej Zolnierkiewicz <bzolnier@xxxxxxxxx> wrote:
> >
> > > The problem looks very similar to the one recently reported by Anders:
> > >
> > > http://lkml.org/lkml/2008/2/22/239
> > >
> > > "Trying out 2.6.25-rc2 smartd always causes my box to hang. I can
> > > switch vt:s and the keyboard seems to work.
> > >
> > > Using sysrq-e I noticed a callpath open -> ext3 -> journals ->
> > > sync_buffer -> io_scheduel -> generic_unplig_device. I'd guess the
> > > open stems from smartd. Removing smartd from the startup, I'm now
> > > using rc2 fine..."
> > >
> > > Initially we thought that it is an IDE regression but after some
> > > testing and further investigation it seems that IDE changes just made
> > > it more likely to occur (yesterday it turned out that the kernel with
> > > the "guilty" IDE commit sometimes boots fine). The issue is easily
> > > reproducible.
> > >
> > > PS We've already verified that it is not PREEMPT related or a compiler
> > > bug.
> >
> > smartd is not active here though - and starting/restarting it doesnt
> > provoke a hang.
>
> I was a bit unclear on this, the problem is easily reproducible but _only_
> on Anders' system (I couldn't reproduce it with smartd here either).

What IO scheduler is Anders using (and does it have an impact, eg does
it hang with deadline as well)?

--
Jens Axboe

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/