title: peak memory measurement of long running process in linux
body: <p>How do I monitor the peak memory consumed by a process in Linux? 
  This is not a program I can internally modify to measure peak memory usage.</p>
  
  <p>I do not really want detailed measurements, nor do I want them to slow down my program excessively.. so valgrind or anything heavyweight is not what I am looking for...
  And like other posts earlier [<a href="https://stackoverflow.com/questions/774556/peak-memory-usage-of-a-linux-unix-process]">Peak memory usage of a linux/unix process</a>, time -v doesn't seem to report memory for my machine...</p>
  
  <p>I can just run top or ps and extract the memory consumed strings for
  my process id using a simple script. However, my process runs for about 20-30 minutes so I want to be able to log and get the max.
  I can tolerate coarse grained samples... every 1-minute or so... Specifically how do I->
  1. fork this simple mem-measure script in zsh?
  2. kill it when the process-under-test finishes?</p>