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> and the unfortunate fact is you can't traverse a tree with constant RAM

This is not true. See Knuth, The Art of Computer Programming Vol.1, § 2.3.5).

Generally I wouldn't recommend naive SDW as a good strategy for filesystems, but if you have a fixed number of processes (common in microcontroller applications) it might be worth trying.



Reading through 2.3.5 (Lists and Garbage Collection), it looks like it's describing a tree where the leaf nodes also contain references to the root of the next tree.

This wouldn't work as a copy-on-write tree, as the root node is changed every write.

Copy-on-write behavior requires very strict trees, and this gets in the way of adding extra structures for traversal.


Pointer swizzling tree traversal requires writes to the tree which isn’t possible in this case.




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