On Tue, 21 Apr 1998 19:30:46 +0200 
 Manuel Bouyer <bouyer@antioche.lip6.fr> wrote:

 > > Out of curiosity... How stable is UVM? How stable is -current in general
 > > right now? I'm itching to start tracking it again. (A related question:
 > > does top work with UVM? If so, does it exhibit the memory leak that seems
 > > to be pretty common after the VM changes that happened during 1.2-current?)
 > 
 > I'm trancking -current (with UVM on) on my home PC, which I use for
 > developpemnts (so it's mostly running X, vi and gcc :). Never got a
 > panic ...
 > However, I'm not sure I would run UVM on a critical server yet. Maybe
 > I'm too timorous :)
 > I would surely run -current/UVM on my desktop PCs and sparc at work too,
 > if I wasn't running INRIA's ipv6 stack on these machines.

I'm running UVM on all of the systems I can run it on, in my small cluster
of machines at work.  One of these systems is a bread-and-butter file
server and build host.  One of them is my desktop workstation (a SPARC).

I've found it to be quite stable.  As a test of my almost-rewrite of
NetBSD/alpha's pmap, I ran a little experiment: I did 4 concurrent
kernel builds, each with a "make -j64".  Needless to say, with all of
those LARGE cc1 processes running, I maxed out physical memory on
my 256M AlphaStation 500.  The UVM kernel fared much better under this
extreme memory load situation than the Mach VM system did (the Mach VM
kernel went catatonic during two of four tries, and UVM kernel survived
all four attempts).

I do notice "mb_map full" a lot when I really pound on my PPro file
server running UVM, but I can't say for sure if it's UVM-related or
not.  I may try using an Intel Etherexpress PRO on that machine to
see if it's the Tulip driver that's causing this to happen.

Jason R. Thorpe                                       thorpej@nas.nasa.gov
NASA Ames Research Center                            Home: +1 408 866 1912
NAS: M/S 258-5                                       Work: +1 650 604 0935
Moffett Field, CA 94035                             Pager: +1 415 428 6939