VM error, unreproducable.

Spirilis (spirilis@mindmeld.dyn.ml.org)
Tue, 7 Jul 1998 19:21:52 -0400 (EDT)

Hi,
Using 2.1.108ac2, earlier I was running a _lot_ of processes on this 486
DX/33 8MB RAM system...
I had one person logged in, one Micq process, one telnet, one BitchX running, an
ssh session, and a MOD playing.
Quite a few hours later, I was doing something in lynx (at the point where lynx
probably had a very big cache going or a lot of memory leaks at the time) and
suddenly I saw a message on the bottom of the screen regarding VM: and something
about freeing a swapped page... but lynx's redraw (while accessing a document)
erased it. Few seconds later, my console was FLOODED with the VM errors, with
another swap_free error. Problem was, they were flooding my console so fast
(and alternately) that I couldn't quite read them in detail, but I did see that
one of them had a memory hex address (something like c0(something)) regarding
swap_free and freeing a swapped page or something
I rebooted using Alt-SysRQ (couldn't get a single key through that mess... and
the HD was cranking only very slowly ... probably b/c most of the CPU time must
have been used up scrolling the console and displaying the message...) and tried
running a hoard of programs again. I had about 11 consoles open, 3 BitchX
processes, 8 lynx processes, and my modified version of mikmod (which supports
memory locking) which was set wit hthe option to lock ALL its pages into
memory... Most of the lynx'es weren't running in true getty logins but I used
open to run them on other consoles...
Plus I was running micq and ssh
But the message never appeared... I waited about 20 minutes of nonstop thrashing
and the system just stabilized.
Oh, and this is BitchX 75 and lynx 2.8.1dev-16 we're talking about.

Here's an idea of what it was like after the thrashing stopped:
7:06pm up 34 min, 11 users, load average: 1.78, 5.29, 5.16
USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT
root tty1 6:32pm 10:41 11.61s 10.46s BitchX
root tty2 6:32pm 22.00s 9.84s 8.87s lynx
root tty3 6:32pm 6:03 1.49s 1.49s zsh
root tty4 6:32pm 29:02 1.21s 0.13s ansitel
root tty5 6:32pm 12:31 6.58s 5.52s BitchX
root tty6 6:32pm 14:17 1:31 1:30 lynx
root tty7 6:39pm 14:18 20.71s 19.62s lynx
root tty8 6:46pm 9.00s 5.08s 3.67s ssh -C -lzephim
root tty9 6:48pm 3.00s 1.57s 0.40s w
root tty13 6:48pm 14:20 3.77s 2.88s lynx
root tty14 6:48pm 6:03 5.74s 4.83s BitchX

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