I am using latest the Raspbian Wheezy release with kernel 3.10. I am running four Python programs 24 hours/day on the Raspberry Pi. Three programs out of four are like background services, which consume at the maximum 2.4% CPU and around 1.2% memory each. The fourth Python code is a pygame application that is displayed on a 1920x1080 screen, which consumes about 50% CPU and 2.4% memory. Thus in total when I am running all 4 programs total memory used is 90 MB and 60% CPU is in use all the time.
The problem is that Raspberry Pi suddenly hangs (no response the keyboard nor mouse, and I'm also not able to ping) after 2-3 days and thus we have to reboot it forcefully. What could be the reason for it to hang? There is no problem of a memory leak since even after 2-3 days the total memory usage and CPU usage is unchanged.