There is a little-known Valgrind tool called "DHAT" (short for "Dynamic Heap Analysis Tool") that's designed to help find exactly these sorts of excessive alloc

There is a little-known Valgrind tool called "DHAT" (short for "Dynamic Heap Analysis Tool") that's designed to help find exactly these sorts of excessive allocations. Here's an old blog post describing it, by DHAT's author: https://blog.mozilla.org/jseward/2010/12/05/fun-n-games-with-dhat/ https://blog.mozilla.org/jseward/2010/12/05/fun-n-games-with... Here's another blog post in which I describe how I used it to speed up the Rust compiler significantly: https://blog.mozilla.org/nnethercote/2016/10/14/how-to-speed-up-the-rust-compiler/ https://blog.mozilla.org/nnethercote/2016/10/14/how-to-speed... And here is the user manual: http://valgrind.org/docs/manual/dh-manual.html http://valgrind.org/docs/manual/dh-manual.html