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Hhaving worked on quite complex embedded projects, my 2 cents is that dynamic allocation should be avoided as much as possible (and its been possible to avoid it 100% of the time for me). Memory layouts are often pre planned, with hand-written linker files, which are sometimes even necessary, as there are quirks like DMA only being able to access certain addresses etc. In embedded, engineers often want hard real time guarantees, very high (essentially unfailing) reliablity, at the lowest possible price points. Dynamic memory allocation is often no good - embedded allocators either waste RAM, have large code sizes, have worse runtimes than their desktop-grade cousins - something like jemalloc generates 10x as much code as the rest of your app, and assumes your heap is at least megabytes in size. On the other hand, embedded-grade allocators often use algorithms that are prone to fragmentation, unpredictable runtimes, and tend to be less tested in general, while still wasting RAM and Flash. Having an allocator that has a bad runtime behavior can basically ruin your hard runtime guarantees, and if you prealloc all you memory you will never run out - on the other hand, even the paper states they measured not calculated the max memory usage, meaning we have no knowledge of what the actual max is. |