I'm running 32-bit Ubuntu 10.04 on a 4-core AMD Phenom machine with 4GB of RAM. With normal use (a dozen or so Chrome tabs, 1 VirtualBox machine, 2 or 3 instances of QtCreator, ) the memory will occasionally fill >95% and the machine will become mostly unresponsive.
If I look at the System Monitor during these periods, it shows the memory usage at 95%+ but only a few hundred MB of my 9GB swap partition are used! Why isn't more memory shifted into swap to avoid running out?
pae
kernel to get that missing 800MiB of RAM.