HTOP is a popular ncurses-based process viewer for Linux. You can scroll through processes horizontally as well as vertically. Killing processes is also quite handy where you do not need to enter the PID.
But have you noticed the color coded bars for CPU, Memory and Swap that comes up when you launch htop. They tell you the usage of respective resources in general but do those green/yellow/red color codes mean anything ?
Those color codes on HTOP mean a lot of things. We will be discussing them here. Let’s start with CPU first.
CPU
You can see 4 different colors for CPU usage.
- Blue, signifies low priority processes usually reniced.
- Green shows the normal priority process.
- Red are the kernel processes.
- Cyan are the Virtual processes in the system.
Memory & Swap
- Green is the used memory by normal processes.
- Blue is the memory used by system buffers.
- Yellow is the memory which is used as system cache.
- Swap is shown using red bars in a separate row.
