How can I measure the actual memory usage of an application or process?

Question

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How do you measure the memory usage of an application or process in Linux?

From the blog articl

Answer 1

I am using Arch Linux and there's this wonderful package called ps_mem:

ps_mem -p 

Example Output

$ ps_mem -S -p $(pgrep firefox)

Private   +   Shared  =  RAM used   Swap used   Program

355.0 MiB +  38.7 MiB = 393.7 MiB    35.9 MiB   firefox
---------------------------------------------
                        393.7 MiB    35.9 MiB
=============================================