The aacraid driver is new to open source and has not seen extensive
testing when compiled as part of the resident kernel. The module
version has seen a number of QA cycles and appears to be very stable.

There is however a known problem when compiling the aacraid driver
as part of the resident kernel in an SMP environment. The end
result is a kernel panic allmost 100% of the time during boot.

It appears the same CPU is trying to acquire the same spinlock more
than once, which we all know is bad. Once this problem has been
resolved, a patch will be distributed.