accidentially stopped my OpenSolaris notebook with mdb

Today I read an article about ZFS performance, where somebody had
problems with the performance.

After disabling ZFS prefetch, his performance was better. So I did the following:

mdb -kw
>zfs_prefetch_disable/W0t1

did some measuring with ptime and set the value back.

mdb -kw
>zfs_prefetch_disable/W0t0

and the fatal error was ending mdb without thinking and just typing exit

>exit


This was a fatal error, because it executes the last action and wrote 0x0 as
the address of the exit function.

As I had typed, I remembered the that I read the following blog:
How to shoot yourself in the foot with mdb

All I had to do, was a hard power reset.