Comment 18 for bug 457767

Looking at the iscsitarget kernel component it seems to be based on r214
of the upstream repository. Looking at that repository there are a number
of fixes there-in but none seem obviously related to the hangs reported.

Looking at the original report and comparing that to Mathias' its not 100%
certain they are showing the same problem. Particularly Mathias' case
seems to show issues somewhat earlier and reports an unwanted interrupt
which may well have been targetted to the virtio_pci module and may
indicate a virtio issue rather than an iscsitarget one.

In both cases we would want to know what the apparently hung processes
are waiting for. It may be possible to get more information on why we are
getting hung up here using 'sysrq-w' which should trigger a dump of any
blocked tasks to the console. Getting that output may help us here.

See below for the kernel documentation on how to trigger the sysrq:

* How do I use the magic SysRq key?
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
On x86 - You press the key combo 'ALT-SysRq-<command key>'. Note - Some
           keyboards may not have a key labeled 'SysRq'. The 'SysRq' key is
           also known as the 'Print Screen' key. Also some keyboards cannot
           handle so many keys being pressed at the same time, so you might
           have better luck with "press Alt", "press SysRq", "release SysRq",
           "press <command key>", release everything.