Swap exhaustion

[Doug Hardie]

I have a process that is eating up 6 GB of swap space.  At that point, FreeBSD 9.3 terminates a process.  However, occasionally its not the one eating up the space.  When I manually quit the process then the swap space returns to a few KB used.  The system runs fine after that.

I have very little knowledge of what this process is doing internally but would like to know what might be causing this issue.  There are 5 of these processes running (parent plus 4 children).  Normally each uses about 90 MB RES/SIZE.  However when the problem occurs they are about 2GB RES/SIZE each.  The system has 4 GB memory.  I thought that a malloc would not be able to grab that much memory, even with swapping as it has to be in memory.  Could a malloc cause this growth in process size or need I look elsewhere?