Re: Deadlocks due to per-process plugging

[Mike Galbraith <efault@gmx.de>]

On Mon, 2012-07-16 at 12:19 +0200, Thomas Gleixner wrote: 
> On Mon, 16 Jul 2012, Mike Galbraith wrote:

> > ---
> >  block/blk-core.c |    1 +
> >  kernel/rtmutex.c |   11 +++++++++--
> >  2 files changed, 10 insertions(+), 2 deletions(-)
> > 
> > --- a/block/blk-core.c
> > +++ b/block/blk-core.c
> > @@ -2782,6 +2782,7 @@ void blk_flush_plug_list(struct blk_plug
> >  	if (q)
> >  		queue_unplugged(q, depth, from_schedule);
> >  }
> > +EXPORT_SYMBOL(blk_flush_plug_list);
> 
> You don't need that one. blk-core and rtmutex are builtin

Box disagrees.

Waiting for device /dev/cciss/c0d0p6 to appear:  ok
fsck from util-linux 2.19.1
[/sbin/fsck.ext3 (1) -- /] fsck.ext3 -a /dev/cciss/c0d0p6 
SLES11: clean, 141001/305824 files, 1053733/1222940 blocks
fsck succeeded. Mounting root device read-write.
Mounting root /dev/cciss/c0d0p6
mount -o rw,acl,user_xattr -t [   27.558934] jbd: disagrees about
version of symbol rt_spin_trylock
ext3 /dev/cciss/[   27.558938] jbd: Unknown symbol rt_spin_trylock (err
-22)
c0d0p6 /root
[   27.558959] jbd: disagrees about version of symbol
__rt_spin_lock_init
[   27.558961] jbd: Unknown symbol __rt_spin_lock_init (err -22)
[   27.558986] jbd: disagrees about version of symbol rt_spin_unlock
[   27.558988] jbd: Unknown symbol rt_spin_unlock (err -22)
[   27.558990] jbd: disagrees about version of symbol rt_spin_lock
[   27.558992] jbd: Unknown symbol rt_spin_lock (err -22)
[   27.559004] jbd: disagrees about version of symbol __rt_mutex_init
[   27.559006] jbd: Unknown symbol __rt_mutex_init (err -22)
modprobe: FATAL: Error inserting ext3
(/lib/modules/3.0.35-rt56-rt/extra/ext3.ko): Invalid argument

mount: unknown filesystem type 'ext3'
could not mount root filesystem -- exiting to /bin/sh
$