The idea that you can classify a programmer's understanding of pointers based on doing linked list tricks is absurd. Usually Linus says things that make sense, but not this time IMHO.
Also the code proposed may work for linked lists that is a very well understood topic, but code like this in general is hard to understand and debug, without actually providing some serious advantage.
I remember some code on the Linux kernel implementing the inode caching in the virtual file system layer that was a mess like that, but multiplied by 1000. Very "Smart" indeed, but for the sake of what?
Also the code proposed may work for linked lists that is a very well understood topic, but code like this in general is hard to understand and debug, without actually providing some serious advantage.
I remember some code on the Linux kernel implementing the inode caching in the virtual file system layer that was a mess like that, but multiplied by 1000. Very "Smart" indeed, but for the sake of what?