On Tue, Jun 13, 2023 at 10:39:06AM +0200, Linus Walleij wrote: > +Paged virtual memory was invented along with virtual memory as a concept in > +1962 on the Ferranti Atlas Computer which was the first computer with paged > +virtual memory. The feature migrated to newer computers and became a de facto > +feature of all Unix-like systems as time went by. In 1985 the feature was > +included in the Intel 80386, which was the CPU Linux 1.0 was developed on. I still don't think the origin story is useful. It's trivia and doesn't help someone understand what they need to know. > +Page tables map virtual addresses as seen by the CPU program counter into > +physical addresses as seen on the external memory bus. This makes it sound like virtual addresses are only used for instructions. I had better wording earlier, but there's no point in repeating it. Just: I dissent. > +Linux defines page tables as a hierarchy which is currently five levels in > +height. The target architecture code for each supported architecture will then > +map this to the restrictions of the target hardware. The word "target" isn't adding any value in this paragraph. Honestly, I don't like much about this document. The writing is flabby and untargetted. Much of my last review was ignored. I'm just going to stop here since I have low confidence that any suggestions would be incorporated.
