Measure the peak memory of the system while a command is running (this only includes physical memory and not virtual memory)

peak_memory.bash

#!/usr/bin/env bash
# peak_memory [command ...]
# Run the given command line in the background and kill if script exits
trap 'kill $(jobs -p) 2&> /dev/null' EXIT
"$@" & 
pid=$! phys_peak=0 not_avail_peak=0
# while command still running
while ps -p $pid &>/dev/null; do
  sleep 1
  mem_total="$(cat /proc/meminfo | grep  'MemTotal:' | grep -oe '\([0-9.]*\)')"
  mem_free="$(cat /proc/meminfo | grep  'MemFree:' | grep -oe '\([0-9.]*\)')"
  mem_avail="$(cat /proc/meminfo | grep  'MemAvailable:' | grep -oe '\([0-9.]*\)')"
  phys=$(($mem_total - $mem_free))
  not_avail=$(($mem_total - $mem_avail))
  let phys_peak='phys > phys_peak ? phys : phys_peak'
  let not_avail_peak='not_avail > not_avail_peak ? not_avail : not_avail_peak'
done
phys_peak=$(($phys_peak / 1048576))
not_avail_peak=$(($not_avail_peak / 1048576))
printf '%s %s\n' "$(date)" "Peak Used Physical memory: $phys_peak GiB" 1>&2
printf '%s %s\n' "$(date)" "Peak Used Not-Available memory (exc. mmap and cache): $not_avail_peak GiB" 1>&2

Example output:

$ peak_memory sleep 2	
Fri Dec  2 14:46:08 GMT 2022 Peak Used Physical memory: 140 GiB	
Fri Dec  2 14:46:08 GMT 2022 Peak Used Not-Available memory (exc. mmap and cache): 17 GiB