In message <Pine.NEB.4.53.0305140954070.23723@woffi.planix.com>, Andreas Wrede 
writes:
>I am running 1.6.1 on a /i386 machine with 128Mb memory. I get regular
>lock-ups during times of high-memory, high-swap activity, typically
>during a nightly rsync run against a large filesystem on a remote
>machine.  I can still break into the debugger, but all higher level
>function are frozen. (I don't even get character echo on the serial
>console). The tracebacks for the last two lock-ups are:

I've seen lockups that I attribute to similar causes.  I haven't been 
able to get into the debugger, but I'm almost always in X.

		--Steve Bellovin, http://www.research.att.com/~smb (me)
		http://www.wilyhacker.com (2nd edition of "Firewalls" book)