During stress test with GENERIC HEAD from Nov 20 08:40 UTC I got: Sleeping on "fdesc" with the following non-sleepable locks held: exclusive sleep mutex fdesc r = 0 (0xc08d15a0) locked @ kern/kern_descrip.c:2425 and then panic: sleeping thread (pid 92279) owns a non-sleepable lock http://www.holm.cc/stress/log/cons89.html -- Peter Holm