I have a program that exhibits the behavior of a memory leak. It gradually takes up all of the systems memory until it fills all swap space and then the operating system kills it. This happens once every several days.
I have extensively profiled the heap in a manner of ways (-hy, -hm, -hc) and tried limiting heap size (-M128M) tweaked the number of generations (-G1) but no matter what I do the heap size appears constant-ish and low always (measured in kB not MB or GB). Yet when I observe the program in htop, its resident memory steadily climbs.
What this indicates to me is that the memory leak is coming from somewhere besides the GHC heap. My program makes use of dependencies, specifically Haskell’s
yaml library which wraps the C library
libyaml, it is possible that the leak is in the number of foreign pointers it has to objects allocated by
My question is threefold:
- What places besides the GHC heap can memory leak from in a Haskell program?
- What tools can I use to track these down?
- What changes to my source code need to be made to avoid these types of leaks, as they seem to differ from the more commonly experienced space leaks in Haskell?