Steps to reproduce:

1. Start Zabbix Server with default StartPreProcessor count (3)
2. Monitor memory usage of Zabbix Server over time
3. Note that server begins to use virtual memory instead of physical memory, behaving very much like a memory leak.
4. Perform a shutdown of zabbix_server and watch the virtual memory usage go down.
5. Watch running processes using a tool like top and note that the process spending the most time terminating is the preprocessing manager.

Result:

Expected:

Preprocessing manager to not use (and continue to increase usage) of virtual memory when physical memory is available.