Debugging Memory Usage in Nim

A few weeks ago I made this little tool for fun to visualize memory usage for multi threaded programs: it injects a little LD_PRELOAD lib overriding malloc() and friends and draws all allocations in a 2D hilbert projection of the heap; nice to get a "feel" of what your program is doing, also fun

Debugging Memory Usage in Nim

Valgrind was the ticket. Very easy to use Massif to find exactly what was growing unbounded over time.

Debugging Memory Usage in Nim

+1 for valgrind, dead simple usage. All my tests were passing until I added valgrind and it caught bunches of mem leaks

Debugging Memory Usage in Nim

Valgrind also has a tool called massif which can be used to track memory allocations:

Debugging Memory Usage in Nim

I haven't found my problem yet but the valgrind suggestion works and looks like it will help. Running a series of tests and I'll analyze the valgrind results in the morning. Thanks, @zevv!

Debugging Memory Usage in Nim

When on Linux: compile with `--debugger:native -d:useMalloc`, put in a `quit()` somewhere and run your program on valgrind; when the process exists valgrind will tell you exactly which memory has been allocated where. Example: type Foo = ref object val: int proc flop

Debugging Memory Usage in Nim

I found and that looks like it will help.

Debugging Memory Usage in Nim

I have a Nim application that hits OOM limits on Linux. I would like to know what objects are taking up all of that memory so I know what to modify. What would be the recommended way to debug this? Application is compiled with `mm:orc` I saw references to a Heap Dump in old versions of the nim