title: Linux perf tools - How to simultaniously profiling multiple processes? How to extract Percentage of CPU cycles?
body: <p>I am trying to profile a set of processes on my CPU. In order to be very precise I want to use the <code>perf stat</code> command to see how many CPU cycles my processes used.
  This is different from top, where I only see the percentage of the CPU used in a snapshot. </p>
  
  <p>Unfortunately I didn't find a way to profile multiple processes at the same time. Is this possible?</p>
  
  <p>And as a second question: Is it possible to not only see the CPU cycles used, but also the total amount of CPU cycles (or the percentage) used in the same time interval?</p>