Hang after running out of memory

[Mike Hunter]

On Apr 20, "Craig Reyenga" wrote:

> I have been following the thread here on current@ about problems occuring
> when running out of memory, so I wrote a C++ program that simply mallocs
> about 144M of memory. My system has 256MB+491MB(swap). I can run the system
> out of memory just fine by running multiple copies of the program, and the
> kernel does kill one if I run too many, however shortly after, when I go to
> killall the programs the system hangs, (although pings, etc manage to
> survive for a few mintues longer) and I have no choice but to press the
> reset button. While it is hung, I _can_ press ^T and it shows the load,
> which increases by 1 about every 45 seconds:
> 
> load: 11.58  cmd: killall 20125 [running] 0.00u 0.00s 11% 292k
> load: 12.27  cmd: killall 20125 [running] 0.00u 0.00s 12% 292k
> 
> Also, the console is just as unusable as any other terminal. I'm not sure
> what is going on, but this is reproducible, and I can post more info upon
> request.

I've experienced similar things after running out of memory.  It seemed
like the scheduler went crazy:  The only way I could get my ssh session to
keep talking was to start other ssh sessions, which would buy me about 20
keystrokes.  shutdown -r got half done and failed into a weird state.  I 
think the kernel was from around April 8.