#!/bin/bash
peak=0
while pid=$1
do
    sample=`cat /proc/$pid/smaps | grep 'Rss:' | awk '{sum += $2} END{print sum}'`
    if [ -n "$sample" ];then
        let peak="sample > peak ? sample : peak"
        sleep 1
    else
        echo "process $pid exit"
        break
    fi
done
echo "memusg: peak=$peak" >&2
echo "pid = $pid"