Google for Linux OOM Killer (Out Of Memory Killer).

It's really annoying, your application may get killed without any way to react, even to just print a "Low memory" error.

The entire concept of the Linux OOM Killer is asinine

It is a well known design feature (I would call it a flaw) of Unix/Linux which makes forking processes with copy-on-write memory possible.

You can run out of both physical memory and swap space. Or your system is swapping is so heavily that, for all practical purposes, the system becomes unusable.

Probably one of the best examples of my claim that UNIX has bad architecture. A well-designed system will either prevent or catch this sort of thing with apps able to detect and/or recover from it without geniuses writing them. Then, there's UNIX/Linux...

I should probably add this to my list of non-security reasons (or an angle at least) for using Nizza-style architecture [1] where critical functionality is taken out of Linux part to run on microkernel or small runtime. Maybe even potential to go further and have such apps that monitor for this sort of thing with a signal to apps that works across platforms. Not just this design flaw, but potentially others where app doesn't have necessary visibility. What you think?

[1] http://genode-labs.com/publications/nizza-2005.pdf

Coming from a Windows viewpoint, I would have thought the same thing. AFAIK, under Windows you just end up hitting the system swap file. Of course, you can start getting into a situation where physical memory is so low that everything grinds to a (ahem, virtual) halt....

Yes, that's the first response. "running out of physical pages" here in the GP really means "running out of free or reclaimable pages and running out of swap".