Comment 4 for bug 182960

@Steve

I stand ready to be corrected, but my understanding is that Linux will only kill processes when it actually runs out of memory. This only happens when it runs out of swap. If a process is out of control, then it will cause the system to thrash the swap and become unusable, but long before Linux runs out of memory to allocate and invokes oom_kill because it can still allocate out of swap.

By this point everything you actually need has gone into swap, so there is a long delay before you can open a terminal window and find and kill the errant process. Less technical users would have to go through System->Administration->System Monitor->Processes->End Process and this would involve many more page faults on the GNOME library and take considerably longer. Even Ctrl-Alt-F1 takes a long time, let alone the time it takes to log in and run top.

We are talking many minutes of swap thrashing before the user can get things back under control. There is a limit to how long the system has slowed to a crawl so much as to be unusable before a user can claim that a hard reboot was the only option. If it takes tens of minutes, then a hard reboot is easier for the user to perform.

Setting a resource limit seems like a much better idea, doesn't it?