severe VM breakaage in 2.1.34

Simon Karpen (slk@teroknor.stu.rpi.edu)
Tue, 15 Apr 1997 09:01:38 -0400 (EDT)


with kernel 2.1.34 on a sparc (sparcstation slc, sun4c, 16mb ram),
the vm subsystem is severely broken.

after running a couple large programs (say an emacs, a sunos netscape),
the system starts to thrash badly doing anything.

while running the emacs:

total used free shared buffers cached
Mem: 14212 14084 128 3200 1028 7372
-/+ buffers: 5684 8528
Swap: 130684 8576 122108

and after running the emacs

Mem: 14212 13748 464 3592 1028 8344
-/+ buffers: 4376 9836
Swap: 130684 5816 124868

note that running this amount of stuff didn't cause severe thrashing
under 2.0.29 or 2.0.30, though in other ways 2.1.34 is a lot faster.
(i.e. sun4c context switch)

has anybody else seen this problem? i also noticed it with 2.1.29.
are there any patches? i really don't understand what's going on in
that part of the kernel very well.

Simon Karpen
karpes@rpi.edu, slk@acm.rpi.edu, slk@karpes.stu.rpi.edu
In a world without fences, who needs Gates?
--Scott McNealy