There are a lot of data points in that report, so we'll break them down: If there are other demands for the RAM that the kernel has poached for its own devices, it relinquishes the memory instantly, so there's no harm done. It's usually just the kernel tenaciously doing its job in the background.
It's easy to get the impression that your system's RAM has been consumed by some runaway process or memory leak, but that's rarely the case. Linux uses any spare RAM for things like file buffer space, to keep your computer running at optimum performance. It's kind of like a mother bird with more open beaks pointed at her than she has the grub for. The kernel referees the memory squabbles and allocates the rationed memory out to all the hungry processes.
RAM is a finite resource that all processes, like applications and daemons, want a piece of. We'll also look at reading /proc/meminfo directly. In this roundup, we'll cover the most commonly used command-line methods: free, vmstat, and top. There are plenty of ways you can get the lowdown on memory usage within your Linux system.
