Ubuntu 10.4 Server x86.
I need to set up a monitor for the physical memory, available for user-space applications.
I.e. "Alert! Soon new allocations will force system to use swap".
But I'm confused by /proc/meminfo output. Which parameter should I monitor? I tried a couple of likely options, but looks like they do not corellate well with what I want. (Perhaps I just looked at a wrong data.)