Lyon,
You need to let all call finishes, and wait a little bit time to let all timers expires, and then see if memory goes back to the value when repro starts.
If you want to check memory leak, run repro with a small CPS, for example 5 or 10 CPS under valgrind, and then let all call finishes, wait a little bit time, then clean shutdown repro, you will see the memory leak.
Another way is to use google
performance tool (http://goog-perftools.sourceforge.net/) to check the memory leak if you do not want to clean shutdown the repro. Google performance tool also does not degrade the performance of repro under high CPS load.
/Kaiduan