Comment 16 for bug 1032550

hmm, try this.

kernel.panic_on_oops = 0
kernel.softlockup_panic = 0
kernel.unknown_nmi_panic = 0
kernel.panic_on_unrecovered_nmi = 0
kernel.panic_on_io_nmi = 0
kernel.hung_task_panic = 0

Make sure these are all set to 1 in /etc/sysctl.conf and then run sysctl -p

Also, lets configure ftrace, see if we get lucky and can catch the deadlock
as it happens.

[as root]
cd /sys/kernel/debug/tracing

echo function > current_tracer
echo 16000 > buffer_size_kb
echo "scsi_*" >> set_ftrace_filter
echo "fc_*" >> set_ftrace_filter

When the kernel crashes, I'll be able to retrieve this buffer from the dump

Should none of the dump triggers work, then just watch it and trigger it yourself.
# echo c > /proc/sysrq-trigger

The hung multipath -v0 processes are usually spawned on behalf of udev events.
Before you begin the test, please record the current dm map (dmsetup table -v)
and the output of (lsscsi -lv) so I have a point of reference. Thanks.