Kernel-3.1 Crash

[Antonio Trande]

>do you have multipath configured on your box?
If i have understand the 'multipath concept', yes. fdisk
output<http://www.fpaste.org/KXvm/>


>How often can you reproduce this problem.
Only with Kernel 3.1.
If fsck is enabled on / partition (btrfs filesystem) also with Kernel 3.0

2011/10/27 Vivek Goyal <vgoyal at redhat.com>

> On Thu, Oct 27, 2011 at 09:31:13PM +0200, Antonio Trande wrote:
> > Should i be the "victim" ? :)
> > If need tests, i'm available.
>
> do you have multipath configured on your box? How often can you reproduce
> this problem.  Can you reproduce the problem with single cpu in the
> system.
>
> Thanks
> Vivek
>
> >
> > 2011/10/27 Vivek Goyal <vgoyal at redhat.com>
> >
> > > On Thu, Oct 27, 2011 at 03:20:51PM -0400, Jeff Moyer wrote:
> > > > Don Zickus <dzickus at redhat.com> writes:
> > > >
> > > > > On Thu, Oct 27, 2011 at 02:43:22PM -0400, Jeff Moyer wrote:
> > > > >> >> This doesn't look like the same problem.  Here we've got BUG:
> > > scheduling
> > > > >> >> while atomic.  If it was the bug fixed by the above commits,
> then
> > > you
> > > > >> >> would hit a BUG_ON.  I would start looking at the btrfs bits to
> see
> > > if
> > > > >> >> they're holding any locks in this code path.
> > > > >> >
> > > > >> > Ignore that one and move to IMG_0350.IMG.  'scheduling while
> atomic'
> > > is
> > > > >> > just noise.  Besides Mike and Vivek told me to blame you for not
> > > pushing
> > > > >> > Jens harder on these fixes. :-)))))
> > > > >>
> > > > >> I'm looking at 0355, which shows the very top of the trace, and
> that
> > > > >> says BUG: scheduling while atomic.  So the problem reported here
> *is*
> > > > >> different from the one fixed by the above two commits.  In fact, I
> > > don't
> > > > >> see evidence of the multipath + flush issue in any of these
> pictures.
> > > > >
> > > > > You have to ignore the 'schedule while atomic' thing it is just a
> > > > >
> > > > > printk("BUG: scheduling while atomic"), it is _not_ a BUG().  :-)
> > > > > (hint read kernel/sched.c::__schedule_bug)
> > > > >
> > > > > I see those messages all the time, it really should be a WARN and
> not a
> > > > > misleading BUG, but whatever.
> > > > >
> > > > > His machine died because the NMI watchdog detected a lockup.  The
> > > lockup
> > > > > was because in blk_insert_cloned_request(), spin_lock_irqsave
> disabled
> > > > > interrupts and spun forever waiting on the q->queue_lock
> > > (IMG_0350.JPG).
> > > > >
> > > > > Mike and Vivek both said that is what you fixed for 3.2.  They also
> > > said
> > > > > the only caller of blk_insert_cloned_request() is multipath, hence
> that
> > > > > argument.  I'll cc them.  Or maybe I can have them walk over to
> your
> > > cube.
> > > > > :-)
> > > >
> > > > Well then they know more than I do.  The bug I fixed would not result
> in
> > > > infinite spinning on the queue lock.  It resulted in a BUG_ON in
> > > > blk_insert_flush, since req->bio was NULL.  So again, I really don't
> see
> > > > how this is related.  We could put this all to rest by asking the
> victim
> > > > to try out those two patches.
> > >
> > > Sorry for the confusion here. We saw the blk_insert_cloned_request() in
> > > the trace and thought it could be related to your fixes. Did not think
> > > about exact symtom of the problem in your case. So you are right. Here
> > > we are spinning on spinlock infinitely and your patch fixed the
> BUG_ON().
> > > So may be it is a different issue.
> > >
> > > Thanks
> > > Vivek
> > >
> >
> >
> >
> > --
> > *Antonio Trande
> > "Fedora Ambassador"
> >
> > **mail*: mailto:sagitter at fedoraproject.org <sagitter at fedoraproject.org>
> > *Homepage*: http://www.fedora-os.org
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>



-- 
*Antonio Trande
"Fedora Ambassador"

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