memstat.c starts a new process and sample its memory usage at a given interval. memreport.py plots the recorded data.

First, record the memory usage of a program with memstat, for example:

memstat 1000 wasmtime run ./pwhash_scrypy

It will start the command wasmtime run ./pwhash_scrypy and sample its memory usage at a interval of 1000 microseconds. The data will be saved in memstat.data.

Then run memreport.py, it will read the recorded data from memstat.data and plot the memory usage of the program over time.

memstat samples the memory usage of a program by perodically read /proc/pid/statm. It just saves the raw output of /proc/pid/statm into memtest.data.

memreport.py plots the memory usage with matplotlib.