On Thu, 27 Jan 2000 04:44:32 -0500 (EST) 
 maximum entropy <entropy@zippy.bernstein.com> wrote:

 > When it hung I was running: "make -j 12 build" in /usr/src; "make
 > build" in /usr/xsrc; screen; top; irc; emacs; StarOffice attempting to
 > load a 4 megabyte RTF file; a full filesystem dump under Amanda;
 > Netscape with about 20 browser windows open; xconsole; an assortment
 > of xterms.
 > 
 > The system happily chugged away for about 3 hours like this, then
 > locked up solid.  
 > 
 > I'm totally out of ideas now...

do you have DDB enabled in your kernel?  If so, dropping into DDB
while running X is going to give the appearance of a "hang".

I'm thinking what happened there is that you ran out of kernel virtual
address space, and went boom.

softdeps is known to be pretty evil with memory management (Frank and
I have some ideas on how to fix it, but there's a decent bit of work
involved).  These other applications that you ran could certainly put
a strain on your KVA space, as well...

        -- Jason R. Thorpe <thorpej@nas.nasa.gov>