Improving performance when target has 100k's of processes

[bobergj]

When entopping a system with 300k processes, it takes quite a while to refresh the process list (up to a minute). Would be cool if entop could use a different update strategy when it discovers that the number of processes is huge.
For example: refresh only top 1000 processes after getting the initial list (starting with the visible ones, and then it can figure out if a process on the top list has been replaced by keeping track of the Min and Max value for the current sort column), and only get the complete process list in the background, every let's say 30 seconds.