How to find out memory layout of your data structure implementation on Linux 64bit machine

Design a code for a data-structure to test

Pre-fill the data-structure under test with significant-values ( 0x00000000, 0x01111111, ... ) highlighting the layout borders & data belonging to data-structure elements

Use debugging tools to view actual live-memory content & layout that the coded data-structure element-under-test uses in-vivo

( be systematic & patient )

Perhaps just traversing the data structure to print element addresses (and sizes if they vary) would give you enough information to feed to for instance graphviz? I'm not sure why did you include the linux-kernel tag. Basic virtual memory mapping happens at page granularity (ignoring huge pages here) so physical vs virtual address don't matter. You can easily do your tests in user space.

I would proceed as follows:

1. place calls to dump your N-ary trees in the code OR use a GDB script to do it
2. write a script in your favourite scripting language to group objects into pages (masking lower 12 bits of addresses out gives page id), calculate statistics, see if objects span multiple pages, do whatever you want; output graphviz description file
3. run graphviz to enjoy the vizualisation

The first thing you need to do is figure out the data you need to represent in graphical format. The memory layout in Poul-Henning Kamp's figures are both the pointer structure, and contiguous virtual memory pages. The former can easily be displayed using a debugging tool like ddd. The latter takes a bit more effort, and there are more ways to accomplish it.

A few ideas...

• Write a function to traverse the data structure and print values, compile as scaffold code and run
• Add function and call it from a debugger, such as gdb
• Write a script to be called from a debugger

Another possibility nobody mentioned yet, would be reading through the specification for the language you're writing the code in. This should generally let you determine the memory layout of the structures in the actual compiled code (C/C++, etc...), neglecting compiler optimization. This can be altered by telling the compiler to lay out the data structures in non-default ways though (alignas, __attribute__(aligned), etc...). You would still need to consider how the memory is allocated from the heap and the operating system.

However, once you have the relevant values, you should be able to use any software you like to convert the data into a graphical format (graphviz, etc...).