9.3-RELEASE still instapanics on multi-mps(4) servers

[wollman at bimajority.org]

In article <4DE72E01E8A64E98A31920FCFCAA5D26 at multiplay.co.uk>,
killing at multiplay.co.uk writes:
>The stack from the panic would be a good start.

As I said, it's in the middle of the USB code, which does not appear,
from my previous bisection, to be connected with the bug at all.  (The
panic is the result of an unhandled trap that happens during
interrupt-driven probing, and it's nearly always in the USB code.  By
loading different modules I can make it happen at slightly different
times and places.)  Six months ago, I found that enabling any form of
memory debugging suppresses the symptoms, although it also kills
performance, of course.  I haven't tried that yet this time around.

Once I get a serial console hooked up I'll be in a better position to
capture the full data (although obviously not a core dump).

-GAWollman