pmap

The command pmap report memory map of a process. Use this command to find out causes of memory bottlenecks.

pmap -d PID

The last line is very important:

• mapped: 933712K total amount of memory mapped to files
• writeable/private: 4304K the amount of private address space
• shared: 768000K the amount of address space this process is sharing with others

Linux find the memory used by a program / process using pmap command