Atop is an ASCII full-screen performance monitor
that is capable of reporting the activity of all
processes (even if processes have finished during
the interval), daily logging of system and process
activity for long-term analysis, highlighting
overloaded system resources by using colors, etc.
At regular intervals, it shows system-level
activity related to the CPU, memory, swap, disks,
and network layers, and for every active process
it shows the CPU utilization, the memory growth,
priority, username, state, and exit code.