DMD is heap profiler built into Firefox, best known for being the tool used to diagnose the sources of “heap-unclassified” memory in about:memory.

It’s been unusable on Win32 for a long time due to incredibly slow start-up times. And recently it became very slow on Mac due to a performance regression in libunwind.

Fortunately I have been able to fix this in both cases (Win32, Mac) by using FramePointerStackWalk() instead of MozStackWalk() to do the stack tracing within DMD. (The Gecko Profiler likewise uses FramePointerStackWalk() on those two platforms, and it was my recent work on the profiler that taught me that there was an alternative stack walker available.)

So DMD should be usable and effective on all Tier 1 platforms. I have tested it on Win32, Win64, Linux64 and Mac. I haven’t tested it in Linux32 or Android. Please let me know if you encounter any problems.