lock order reversals - what do they mean?

[C. Kukulies]

I'm getting 
lock order reversal
 1st 0xc09524c0 UMA lock (UMA lock) @ /u/src/sys/vm/uma_core.c:1200
 2nd 0xc1431100 system map (system map) @ /u/src/sys/vm/vm_map.c:2210
Stack backtrace:

This happenend while doing a find . something on my notebook hd.

--
Chris Christoph P. U. Kukulies kuku_at_physik.rwth-aachen.de